mpv/demux/demux_timeline.c

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Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
/*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* mpv is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <assert.h>
#include <limits.h>
#include "common/common.h"
#include "common/msg.h"
#include "demux.h"
#include "timeline.h"
#include "stheader.h"
#include "stream/stream.h"
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
struct segment {
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
int index; // index into virtual_source.segments[] (and timeline.parts[])
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
double start, end;
double d_start;
char *url;
bool lazy;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
struct demuxer *d;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
// stream_map[sh_stream.index] = virtual_stream, where sh_stream is a stream
// from the source d, and virtual_stream is a streamexported by the
// timeline demuxer (virtual_stream.sh). It's used to map the streams of the
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
// source onto the set of streams of the virtual timeline.
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
// Uses NULL for streams that do not appear in the virtual timeline.
struct virtual_stream **stream_map;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
int num_stream_map;
};
// Information for each stream on the virtual timeline. (Mirrors streams
// exposed by demux_timeline.)
struct virtual_stream {
struct sh_stream *sh; // stream exported by demux_timeline
bool selected; // ==demux_stream_is_selected(sh)
int eos_packets; // deal with b-frame delay
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
struct virtual_source *src; // group this stream is part of
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
};
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
// This represents a single timeline source. (See timeline.next. For each
// timeline struct there is a virtual_source.)
struct virtual_source {
struct timeline_par *tl;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
bool dash, no_clip;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
struct segment **segments;
int num_segments;
struct segment *current;
struct virtual_stream **streams;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
int num_streams;
// Total number of packets received past end of segment. Used
// to be clever about determining when to switch segments.
int eos_packets;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
bool eof_reached;
double dts; // highest read DTS (or PTS if no DTS available)
bool any_selected; // at least one stream is actually selected
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
struct demux_packet *next;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
};
struct priv {
struct timeline *tl;
double duration;
// As the demuxer user sees it.
struct virtual_stream **streams;
int num_streams;
struct virtual_source **sources;
int num_sources;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
};
static bool add_tl(struct demuxer *demuxer, struct timeline_par *par);
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
static bool do_read_next_packet(struct demuxer *demuxer,
struct virtual_source *src);
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
static void update_slave_stats(struct demuxer *demuxer, struct demuxer *slave)
{
demux_report_unbuffered_read_bytes(demuxer, demux_get_bytes_read_hack(slave));
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
static bool target_stream_used(struct segment *seg, struct virtual_stream *vs)
{
for (int n = 0; n < seg->num_stream_map; n++) {
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
if (seg->stream_map[n] == vs)
return true;
}
return false;
}
// Create mapping from segment streams to virtual timeline streams.
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
static void associate_streams(struct demuxer *demuxer,
struct virtual_source *src,
struct segment *seg)
{
if (!seg->d || seg->stream_map)
return;
int num_streams = demux_get_num_stream(seg->d);
for (int n = 0; n < num_streams; n++) {
struct sh_stream *sh = demux_get_stream(seg->d, n);
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
struct virtual_stream *other = NULL;
for (int i = 0; i < src->num_streams; i++) {
struct virtual_stream *vs = src->streams[i];
// The stream must always have the same media type. Also, a stream
// can't be assigned multiple times.
if (sh->type != vs->sh->type || target_stream_used(seg, vs))
continue;
// By default pick the first matching stream.
if (!other)
other = vs;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
// Matching by demuxer ID is supposedly useful and preferable for
// ordered chapters.
if (sh->demuxer_id == vs->sh->demuxer_id)
other = vs;
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
MP_TARRAY_APPEND(seg, seg->stream_map, seg->num_stream_map, other);
}
}
static void reselect_streams(struct demuxer *demuxer)
{
struct priv *p = demuxer->priv;
for (int n = 0; n < p->num_streams; n++) {
struct virtual_stream *vs = p->streams[n];
vs->selected = demux_stream_is_selected(vs->sh);
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
for (int x = 0; x < p->num_sources; x++) {
struct virtual_source *src = p->sources[x];
for (int n = 0; n < src->num_segments; n++) {
struct segment *seg = src->segments[n];
if (!seg->d)
continue;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
for (int i = 0; i < seg->num_stream_map; i++) {
bool selected =
seg->stream_map[i] && seg->stream_map[i]->selected;
// This stops demuxer readahead for inactive segments.
if (!src->current || seg->d != src->current->d)
selected = false;
struct sh_stream *sh = demux_get_stream(seg->d, i);
demuxer_select_track(seg->d, sh, MP_NOPTS_VALUE, selected);
update_slave_stats(demuxer, seg->d);
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
}
}
bool was_selected = src->any_selected;
src->any_selected = false;
for (int n = 0; n < src->num_streams; n++)
src->any_selected |= src->streams[n]->selected;
if (!was_selected && src->any_selected) {
src->eof_reached = false;
src->dts = MP_NOPTS_VALUE;
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
TA_FREEP(&src->next);
}
}
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
static void close_lazy_segments(struct demuxer *demuxer,
struct virtual_source *src)
{
// unload previous segment
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
for (int n = 0; n < src->num_segments; n++) {
struct segment *seg = src->segments[n];
if (seg != src->current && seg->d && seg->lazy) {
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
TA_FREEP(&src->next); // might depend on one of the sub-demuxers
demux_free(seg->d);
seg->d = NULL;
}
}
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
static void reopen_lazy_segments(struct demuxer *demuxer,
struct virtual_source *src)
{
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
if (src->current->d)
return;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
close_lazy_segments(demuxer, src);
struct demuxer_params params = {
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
.init_fragment = src->tl->init_fragment,
.skip_lavf_probing = true,
};
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
src->current->d = demux_open_url(src->current->url, &params,
demuxer->cancel, demuxer->global);
if (!src->current->d && !demux_cancel_test(demuxer))
MP_ERR(demuxer, "failed to load segment\n");
if (src->current->d)
update_slave_stats(demuxer, src->current->d);
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
associate_streams(demuxer, src, src->current);
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
static void switch_segment(struct demuxer *demuxer, struct virtual_source *src,
struct segment *new, double start_pts, int flags,
bool init)
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
{
if (!(flags & SEEK_FORWARD))
flags |= SEEK_HR;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
MP_VERBOSE(demuxer, "switch to segment %d\n", new->index);
if (src->current && src->current->d)
update_slave_stats(demuxer, src->current->d);
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
src->current = new;
reopen_lazy_segments(demuxer, src);
if (!new->d)
return;
reselect_streams(demuxer);
if (!src->no_clip)
demux_set_ts_offset(new->d, new->start - new->d_start);
if (!src->no_clip || !init)
demux_seek(new->d, start_pts, flags);
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
for (int n = 0; n < src->num_streams; n++) {
struct virtual_stream *vs = src->streams[n];
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
vs->eos_packets = 0;
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
src->eof_reached = false;
src->eos_packets = 0;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
static void seek_source(struct demuxer *demuxer, struct virtual_source *src,
double pts, int flags)
{
struct segment *new = src->segments[src->num_segments - 1];
for (int n = 0; n < src->num_segments; n++) {
if (pts < src->segments[n]->end) {
new = src->segments[n];
break;
}
}
switch_segment(demuxer, src, new, pts, flags, false);
src->dts = MP_NOPTS_VALUE;
TA_FREEP(&src->next);
}
static void d_seek(struct demuxer *demuxer, double seek_pts, int flags)
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
{
struct priv *p = demuxer->priv;
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
seek_pts = seek_pts * ((flags & SEEK_FACTOR) ? p->duration : 1);
flags &= SEEK_FORWARD | SEEK_HR;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
// The intention is to seek audio streams to the same target as video
// streams if they are separate streams. Video streams usually have more
// coarse keyframe snapping, which could leave video without audio.
struct virtual_source *master = NULL;
bool has_slaves = false;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
for (int x = 0; x < p->num_sources; x++) {
struct virtual_source *src = p->sources[x];
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
bool any_audio = false, any_video = false;
for (int i = 0; i < src->num_streams; i++) {
struct virtual_stream *str = src->streams[i];
if (str->selected) {
if (str->sh->type == STREAM_VIDEO)
any_video = true;
if (str->sh->type == STREAM_AUDIO)
any_audio = true;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
}
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
if (any_video)
master = src;
// A true slave stream is audio-only; this also prevents that the master
// stream is considered a slave stream.
if (any_audio && !any_video)
has_slaves = true;
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
if (!has_slaves)
master = NULL;
if (master) {
seek_source(demuxer, master, seek_pts, flags);
do_read_next_packet(demuxer, master);
if (master->next && master->next->pts != MP_NOPTS_VALUE) {
// Assume we got a seek target. Actually apply the heuristic.
MP_VERBOSE(demuxer, "adjust seek target from %f to %f\n", seek_pts,
master->next->pts);
seek_pts = master->next->pts;
flags &= ~(unsigned)SEEK_FORWARD;
}
}
for (int x = 0; x < p->num_sources; x++) {
struct virtual_source *src = p->sources[x];
if (src != master)
seek_source(demuxer, src, seek_pts, flags);
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
}
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
static bool d_read_packet(struct demuxer *demuxer, struct demux_packet **out_pkt)
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
{
struct priv *p = demuxer->priv;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
struct virtual_source *src = NULL;
for (int x = 0; x < p->num_sources; x++) {
struct virtual_source *cur = p->sources[x];
if (!cur->any_selected || cur->eof_reached)
continue;
if (!cur->current)
switch_segment(demuxer, cur, cur->segments[0], 0, 0, true);
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
if (!cur->any_selected || !cur->current || !cur->current->d)
continue;
if (!src || cur->dts == MP_NOPTS_VALUE ||
(src->dts != MP_NOPTS_VALUE && cur->dts < src->dts))
src = cur;
}
if (!src)
return false;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
if (!do_read_next_packet(demuxer, src))
return false;
*out_pkt = src->next;
src->next = NULL;
return true;
}
static bool do_read_next_packet(struct demuxer *demuxer,
struct virtual_source *src)
{
if (src->next)
return 1;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
struct segment *seg = src->current;
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
if (!seg || !seg->d)
return 0;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
struct demux_packet *pkt = demux_read_any_packet(seg->d);
if (!pkt || (!src->no_clip && pkt->pts >= seg->end))
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
src->eos_packets += 1;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
update_slave_stats(demuxer, seg->d);
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
// Test for EOF. Do this here to properly run into EOF even if other
// streams are disabled etc. If it somehow doesn't manage to reach the end
// after demuxing a high (bit arbitrary) number of packets, assume one of
// the streams went EOF early.
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
bool eos_reached = src->eos_packets > 0;
if (eos_reached && src->eos_packets < 100) {
for (int n = 0; n < src->num_streams; n++) {
struct virtual_stream *vs = src->streams[n];
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
if (vs->selected) {
int max_packets = 0;
if (vs->sh->type == STREAM_AUDIO)
max_packets = 1;
if (vs->sh->type == STREAM_VIDEO)
max_packets = 16;
eos_reached &= vs->eos_packets >= max_packets;
}
}
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
src->eof_reached = false;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
if (eos_reached || !pkt) {
talloc_free(pkt);
struct segment *next = NULL;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
for (int n = 0; n < src->num_segments - 1; n++) {
if (src->segments[n] == seg) {
next = src->segments[n + 1];
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
break;
}
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
if (!next) {
src->eof_reached = true;
return false;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
}
switch_segment(demuxer, src, next, next->start, 0, true);
return true; // reader will retry
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
if (pkt->stream < 0 || pkt->stream >= seg->num_stream_map)
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
goto drop;
if (!src->no_clip) {
pkt->segmented = true;
if (!pkt->codec)
pkt->codec = demux_get_stream(seg->d, pkt->stream)->codec;
if (pkt->start == MP_NOPTS_VALUE || pkt->start < seg->start)
pkt->start = seg->start;
if (pkt->end == MP_NOPTS_VALUE || pkt->end > seg->end)
pkt->end = seg->end;
}
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
struct virtual_stream *vs = seg->stream_map[pkt->stream];
if (!vs)
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
goto drop;
// for refresh seeks, demux.c prefers monotonically increasing packet pos
// since the packet pos is meaningless anyway for timeline, use it
if (pkt->pos >= 0)
pkt->pos |= (seg->index & 0x7FFFULL) << 48;
if (pkt->pts != MP_NOPTS_VALUE && !src->no_clip && pkt->pts >= seg->end) {
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
// Trust the keyframe flag. Might not always be a good idea, but will
// be sufficient at least with mkv. The problem is that this flag is
// not well-defined in libavformat and is container-dependent.
if (pkt->keyframe || vs->eos_packets == INT_MAX) {
vs->eos_packets = INT_MAX;
goto drop;
} else {
vs->eos_packets += 1;
}
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
double dts = pkt->dts != MP_NOPTS_VALUE ? pkt->dts : pkt->pts;
if (src->dts == MP_NOPTS_VALUE || (dts != MP_NOPTS_VALUE && dts > src->dts))
src->dts = dts;
pkt->stream = vs->sh->index;
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
src->next = pkt;
return true;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
drop:
talloc_free(pkt);
return true;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
static void print_timeline(struct demuxer *demuxer)
{
struct priv *p = demuxer->priv;
MP_VERBOSE(demuxer, "Timeline segments:\n");
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
for (int x = 0; x < p->num_sources; x++) {
struct virtual_source *src = p->sources[x];
if (x >= 1)
MP_VERBOSE(demuxer, " --- new parallel stream ---\n");
for (int n = 0; n < src->num_segments; n++) {
struct segment *seg = src->segments[n];
int src_num = n;
for (int i = 0; i < n; i++) {
if (seg->d && src->segments[i]->d == seg->d) {
src_num = i;
break;
}
}
MP_VERBOSE(demuxer, " %2d: %12f - %12f [%12f] (",
n, seg->start, seg->end, seg->d_start);
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
for (int i = 0; i < seg->num_stream_map; i++) {
struct virtual_stream *vs = seg->stream_map[i];
MP_VERBOSE(demuxer, "%s%d", i ? " " : "",
vs ? vs->sh->index : -1);
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
MP_VERBOSE(demuxer, ")\n source %d:'%s'\n", src_num, seg->url);
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
if (src->dash)
MP_VERBOSE(demuxer, " (Using pseudo-DASH mode.)\n");
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
MP_VERBOSE(demuxer, "Total duration: %f\n", p->duration);
}
static int d_open(struct demuxer *demuxer, enum demux_check check)
{
struct priv *p = demuxer->priv = talloc_zero(demuxer, struct priv);
p->tl = demuxer->params ? demuxer->params->timeline : NULL;
if (!p->tl || p->tl->num_pars < 1)
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
return -1;
demuxer->chapters = p->tl->chapters;
demuxer->num_chapters = p->tl->num_chapters;
struct demuxer *meta = p->tl->meta;
if (!meta)
return -1;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
demuxer->metadata = meta->metadata;
demuxer->attachments = meta->attachments;
demuxer->num_attachments = meta->num_attachments;
demuxer->editions = meta->editions;
demuxer->num_editions = meta->num_editions;
demuxer->edition = meta->edition;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
for (int n = 0; n < p->tl->num_pars; n++) {
if (!add_tl(demuxer, p->tl->pars[n]))
return -1;
}
if (!p->num_sources)
return -1;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
demuxer->is_network |= p->tl->is_network;
demuxer->is_streaming |= p->tl->is_streaming;
demuxer->duration = p->duration;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
print_timeline(demuxer);
demuxer->seekable = true;
demuxer->partially_seekable = false;
demuxer->filetype = talloc_asprintf(p, "%s/%s",
p->tl->format,
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
meta->filetype ? meta->filetype : meta->desc->name);
reselect_streams(demuxer);
return 0;
}
static bool add_tl(struct demuxer *demuxer, struct timeline_par *tl)
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
{
struct priv *p = demuxer->priv;
struct virtual_source *src = talloc_ptrtype(p, src);
*src = (struct virtual_source){
.tl = tl,
.dash = tl->dash,
.no_clip = tl->no_clip || tl->dash,
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
.dts = MP_NOPTS_VALUE,
};
if (!tl->num_parts || !tl->track_layout)
return false;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
MP_TARRAY_APPEND(p, p->sources, p->num_sources, src);
p->duration = MPMAX(p->duration, tl->parts[tl->num_parts - 1].end);
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
struct demuxer *meta = tl->track_layout;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
int num_streams = demux_get_num_stream(meta);
for (int n = 0; n < num_streams; n++) {
struct sh_stream *sh = demux_get_stream(meta, n);
struct sh_stream *new = demux_alloc_sh_stream(sh->type);
new->demuxer_id = sh->demuxer_id;
new->codec = sh->codec;
new->title = sh->title;
new->lang = sh->lang;
new->default_track = sh->default_track;
new->forced_track = sh->forced_track;
new->hls_bitrate = sh->hls_bitrate;
new->missing_timestamps = sh->missing_timestamps;
new->attached_picture = sh->attached_picture;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
demux_add_sh_stream(demuxer, new);
struct virtual_stream *vs = talloc_ptrtype(p, vs);
*vs = (struct virtual_stream){
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
.src = src,
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
.sh = new,
};
MP_TARRAY_APPEND(p, p->streams, p->num_streams, vs);
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
assert(demux_get_stream(demuxer, p->num_streams - 1) == new);
MP_TARRAY_APPEND(src, src->streams, src->num_streams, vs);
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
for (int n = 0; n < tl->num_parts; n++) {
struct timeline_part *part = &tl->parts[n];
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
// demux_timeline already does caching, doing it for the sub-demuxers
// would be pointless and wasteful.
if (part->source) {
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
demuxer->is_network |= part->source->is_network;
demuxer->is_streaming |= part->source->is_streaming;
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
struct segment *seg = talloc_ptrtype(src, seg);
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
*seg = (struct segment){
.d = part->source,
.url = part->source ? part->source->filename : part->url,
.lazy = !part->source,
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
.d_start = part->source_start,
.start = part->start,
.end = part->end,
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
};
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
associate_streams(demuxer, src, seg);
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
seg->index = n;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
MP_TARRAY_APPEND(src, src->segments, src->num_segments, seg);
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
demuxer->is_network |= tl->track_layout->is_network;
demuxer->is_streaming |= tl->track_layout->is_streaming;
return true;
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
static void d_close(struct demuxer *demuxer)
{
struct priv *p = demuxer->priv;
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
for (int x = 0; x < p->num_sources; x++) {
struct virtual_source *src = p->sources[x];
src->current = NULL;
demux_timeline: add heuristic to fix shifted seeks with separate audio If you have a EDL stream with separate sources for audio and video stream (like ytdl_hook now creates), you can get the problem that the video stream seeks to a different position than audio due to different key frame granularity. In particular, if you seek backward, the video might undershoot the seek target by a lot. Then video will resume from an earlier position than audio, and the player plays silence. This is annoying. Fix this by explicitly implementing a heuristic to detect separate audio/video streams, determining where a video seek ends up, and then seeking the audio stream to the video destination. This also makes sure to not seek audio with SEEK_FORWARD, so it will always seek before the video position. Non-precise seeks still skip audio to the video target, so this helps with ensuring that audio is present at the final seek target. The implementation is very annoying, because the only way to determine the seek target is to actually read a packet. Thus a 1-packet queue needs to be added. In theory, we could get the seek target from the index of the video file (especially if it's mp4), but libavformat does not have public API that exports this index, so we're stuck with this roundabout generic method. Note that this is only for non-precise seeks. If precise seeks are done, the problem is handled by the frontend by skipping unwanted video frames. But non-precise seeking should still work. (Personally I prefer non-precise seek mode by default because they're still significantly faster.) It also needs to be said that this is the 4th implementation of this seek adjustment thing in mpv. The 1st implementation is in the frontend (look for MPContext.seek_slave). This works only if the external audio stream is known as such on the frontend level. The 2nd implementation is in the demuxer level packet cache (top of execute_cache_seek()). This is similar to code that any demuxer needs to handle non-precise seeks sufficiently nicely. The 3rd is in demux_mkv.c. Since mkv is an interleaved format, this implementation mostly consists on trying to pick index entries for video packets if a video stream is selected. Maybe these "redundant" implementations could be avoided by exposing separate streams through the demuxer API (and making them individually seekable) or something like this, but this is messy and not without problems for multiple reasons. So for now this commit is the best way to fix the observed behavior.
2019-01-11 14:04:43 +00:00
TA_FREEP(&src->next);
demux, demux_edl: add extension for tracks sourced from separate streams This commit adds an extension to mpv EDL, which basically allows you to do the same as --audio-file, --external-file, etc. in a single EDL file. This is a relatively quick & dirty implementation. The dirty part lies in the fact that several shortcuts are taken. For example, struct timeline now forms a singly linked list, which is really weird, but also means the other timeline using demuxers (cue, mkv) don't need to be touched. Also, memory management becomes even worse (weird object ownership rules that are just fragile WTFs). There are some other dubious small changes, mostly related to the weird representation of separate streams. demux_timeline.c contains the actual implementation of the separate stream handling. For the most part, most things that used to be on the top level are now in struct virtual_source, of which one for each separate stream exists. This is basically like running multiple demux_edl.c in parallel. Some changes could strictly speaking be split into a separate commit, such as the stream_map type change. Mostly untested. Seems to work for the intended purpose. Potential for regressions for other timeline uses (like ordered chapters) is probably low. One thing which could definitely break and which I didn't test is the pseudo-DASH fragmented EDL code, of which ytdl can trigger various forms in obscure situations. (Uh why don't we have a test suite.) Background: The intention is to use this for the ytdl wrapper. A certain streaming site from a particularly brain damaged and plain evil Silicon Valley company usually provides streams as separate audio and video streams. The ytdl wrapper simply does use audio-add (i.e. adding it as external track, like with --audio-file), which works mostly fine. Unfortunately, mpv manages caching completely separately for external files. This has the following potential problems: 1. Seek ranges are rendered incorrectly. They always use the "main" stream, in this case the video stream. E.g. clicking into a cached range on the OSC could trigger a low level seek if the audio stream is actually not cached at the target position. 2. The stream cache bloats unnecessarily. Each stream may allocate the full configured maximum cache size, which is not what the user intends to do. Cached ranges are not pruned the same way, which creates disjoint cache ranges, which only use memory and won't help with fast seeking or playback. 3. mpv will try to aggressively read from both streams. This is done from different threads, with no regard which stream is more important. So it might happen that one stream starves the other one, especially if they have different bitrates. 4. Every stream will use a separate thread, which is an unnecessary waste of system resources. In theory, the following solutions are available (this commit works towards D): A. Centrally manage reading and caching of all streams. A single thread would do all I/O, and decide from which stream it should read next. As long as the total TCP/socket buffering is not too high, this should be effective to avoid starvation issues. This can also manage the cached ranges better. It would also get rid of the quite useless additional demuxer threads. This solution is conceptually simple, but requires refactoring the entire demuxer middle layer. B. Attempt to coordinate the demuxer threads. This would maintain a shared cache and readahead state to solve the mentioned problems explicitly. While this sounds simple and like an incremental change, it's probably hard to implement, creates more messy special cases, solution A. seems just a better and simpler variant of this. (On the other hand, A. requires refactoring more code.) C. Render an intersection of the seek ranges across all streams. This fixes only problem 1. D. Merge all streams in a dedicated wrapper demuxer. The general demuxer layer remains unchanged, and reading from separate streams is handled as special case. This effectively achieves the same as A. In particular, caching is simply handled by the usual demuxer cache layer, which sees the wrapper demuxer as a single stream of interleaved packets. One implementation variant of this is to reuse the EDL infrastructure, which this commit does. All in all, solution A would be preferable, because it's cleaner and works for all external streams in general. Some previous commit tried to prepare for implementing solution A. This could still happen. But it could take years until this is finally seriously started and finished. In any case, this commit doesn't block or complicate such attempts, which is also why it's the way to go. It's worth mentioning that original mplayer handles external files by creating a wrapper demuxer. This is like a less ideal mixture of A. and D. (The similarity with A. is that extending the mplayer approach to be fully dynamic and without certain disadvantages caused by the wrapper would end up with A. anyway. The similarity with D. is that due to the wrapper, no higher level code needs to be changed.)
2019-01-04 12:09:02 +00:00
close_lazy_segments(demuxer, src);
}
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
struct demuxer *master = p->tl->demuxer;
timeline_destroy(p->tl);
demux_free(master);
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
static void d_switched_tracks(struct demuxer *demuxer)
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
{
reselect_streams(demuxer);
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
}
const demuxer_desc_t demuxer_desc_timeline = {
.name = "timeline",
.desc = "timeline segments",
.read_packet = d_read_packet,
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
.open = d_open,
.close = d_close,
.seek = d_seek,
.switched_tracks = d_switched_tracks,
Rewrite ordered chapters and timeline stuff This uses a different method to piece segments together. The old approach basically changes to a new file (with a new start offset) any time a segment ends. This meant waiting for audio/video end on segment end, and then changing to the new segment all at once. It had a very weird impact on the playback core, and some things (like truly gapless segment transitions, or frame backstepping) just didn't work. The new approach adds the demux_timeline pseudo-demuxer, which presents an uniform packet stream from the many segments. This is pretty similar to how ordered chapters are implemented everywhere else. It also reminds of the FFmpeg concat pseudo-demuxer. The "pure" version of this approach doesn't work though. Segments can actually have different codec configurations (different extradata), and subtitles are most likely broken too. (Subtitles have multiple corner cases which break the pure stream-concatenation approach completely.) To counter this, we do two things: - Reinit the decoder with each segment. We go as far as allowing concatenating files with completely different codecs for the sake of EDL (which also uses the timeline infrastructure). A "lighter" approach would try to make use of decoder mechanism to update e.g. the extradata, but that seems fragile. - Clip decoded data to segment boundaries. This is equivalent to normal playback core mechanisms like hr-seek, but now the playback core doesn't need to care about these things. These two mechanisms are equivalent to what happened in the old implementation, except they don't happen in the playback core anymore. In other words, the playback core is completely relieved from timeline implementation details. (Which honestly is exactly what I'm trying to do here. I don't think ordered chapter behavior deserves improvement, even if it's bad - but I want to get it out from the playback core.) There is code duplication between audio and video decoder common code. This is awful and could be shareable - but this will happen later. Note that the audio path has some code to clip audio frames for the purpose of codec preroll/gapless handling, but it's not shared as sharing it would cause more pain than it would help.
2016-02-15 20:04:07 +00:00
};