Instead of weirdly deciding this on every packet read and having the
code far away from where it's actually needed, just run it where it's
actually needed.
A typical idiom for calling functions that remove something from the
array being iterated, but it's not needed here. I have no idea why this
was ever done.
Setting ds->refreshing for unselected streams could lead to a
nonsensical queue overflow warning, because read_packet() took it as a
reason to continue reading.
Also add some more information to the queue overflow warning (even if
that one doesn't have anything to do with this bug - it was for
unselected streams only).
This fixes an endless loop with threading disabled, such as for example
when playing a file with an external subtitle file, and seeking to the
beginning. Something will set in->seeking, but the seek is never
executed, which made demux_read_packet() loop endlessly. (External
subtitles will use non-threaded mode for whatever reasons.)
Fix this by by making the unthreaded code to execute the worker thread
body, which reduces the difference in logic.
Until now, the demuxer cache was limited to a single range. Extend this
to multiple range. Should be useful for slow network streams.
This commit changes a lot in the internal demuxer cache logic, so
there's a lot of room for bugs and regressions. The logic without
demuxer cache is mostly untouched, but also involved with the code
changes. Or in other words, this commit probably fucks up shit.
There are two things which makes multiple cached ranges rather hard:
1. the need to resume the demuxer at the end of a cached range when
seeking to it
2. joining two adjacent ranges when the lowe range "grows" into it (and
resuming the demuxer at the end of the new joined range)
"Resuming" the demuxer means that we perform a low level seek to the end
of a cached range, and properly append new packets to it, without adding
packets multiple times or creating holes due to missing packets.
Since audio and video never line up exactly, there is no clean "cut"
possible, at which you could resume the demuxer cleanly (for 1.) or
which you could use to detect that two ranges are perfectly adjacent
(for 2.). The way how the demuxer interleaves multiple streams is also
unpredictable. Typically you will have to expect that it randomly allows
one of the streams to be ahead by a bit, and so on.
To deal with this, we have heuristics in place to detect when one packet
equals or is "behind" a packet that was demuxed earlier. We reuse the
refresh seek logic (used to "reread" packets into the demuxer cache when
enabling a track), which checks for certain packet invariants.
Currently, it observes whether either the raw packet position, or the
packet DTS is strictly monotonically increasing. If none of them are
true, we discard old ranges when creating a new one.
This heavily depends on the file format and the demuxer behavior. For
example, not all file formats have DTS, and the packet position can be
unset due to libavformat not always setting it (e.g. when parsers are
used).
At the same time, we must deal with all the complicated state used to
track prefetching and seek ranges. In some complicated corner cases, we
just give up and discard other seek ranges, even if the previously
mentioned packet invariants are fulfilled.
To handle joining, we're being particularly dumb, and require a small
overlap to be confident that two ranges join perfectly. (This could be
done incrementally with as little overlap as 1 packet, but corner cases
would eat us: each stream needs to be joined separately, and the cache
pruning logic could remove overlapping packets for other streams again.)
Another restriction is that switching the cached range will always
trigger an asynchronous low level seek to resume demuxing at the new
range. Some users might find this annoying.
Dealing with interleaved subtitles is not fully handled yet. It will
clamp the seekable range to where subtitle packets are.
libavcodec can't deal with them, because its API doesn't distinguish
between 0 sized packets and sending EOF. As such, keeping them doesn't
do any good, ever. This actually fixes some obscure mkv sample (see
previous commit).
This adds a bunch of stuff (mostly unused or redundant) as preparation
for supporting multiple seek ranges. Actual support is probably still
far away.
One change that messes deeper with the actual code is that we account
for total buffered bytes instead of just the backwards bytes now. This
way, prune_old_packets() doesn't have to iterate over all seek ranges to
determine whether something needs pruning.
The main purpose of this commit is avoiding any hidden O(n^2) algorithms
in the code for pruning the demuxer cache, and for determining the
seekable boundaries of the cache. The old code could loop over the whole
packet queue on every packet pruned in certain corner cases.
There are two ways how to reach the goal:
1) commit a cardinal sin
2) do everything incrementally
The cardinal sin is adding an extra field to demux_packet, which caches
the determined seekable range for a keyframe range. demux_packet is a
rather general data structure and thus shouldn't have any fields that
are not inherent to its use, and are only needed as an implementation
detail of code using it. But what are you gonna do, sue me?
In the future, demux.c might have its own packet struct though. Then the
other existing cardinal sin (the "next" field, from MPlayer times) could
be removed as well.
This commit also changes slightly how the seek end is determined. There
is a note on the manpage in case anyone finds the new behavior
confusing. It's somewhat cleaner and might be needed for supporting
multiple ranges (although that's unclear).
The demuxer cache seeking mechanism looks at keyframe ranges to
determine the earlierst PTS of a packet. Instead of looping over all
packets twice (once to find the next keyframe, a second time to find the
seek PTS), do it in one go.
For that basically turn recompute_keyframe_target_pts() into an
iteration functionn. Functionality should be unchanged with this commit.
The base_ts field is used to guess the decoder position, and when set to
NOPTS, it just read ahead arbitrarily. Also demux_add_packet() sets
base_ts to the new timestamp when appending a packet, which would also
make it readahead by a too large amount.
Fix this by setting base_ts after a seek. This assumes that normally, a
cached seek target will always have the timestamp set. This is actually
not quite clear (as it calls recompute_keyframe_target_pts(), which
looks at multiple packets), but maybe it works well enough.
Don't do any of the extra work related to pruning the backbuffer if
demuxer cache seeking is disabled.
As a small extra, always prune packets with no timestamps immediately,
or queue heads that are not keyframes. (Both of them would be pruned
from the backbuffer by the normal logic anyway.)
If fulfilling --demuxer-readahead-secs requires more memory than allowed
by --demuxer-max-bytes, the queue obviously overflows. But the warning
is normally only for the case when trying to find the next video or
audio packet fails, and decoding can't continue.
Use a separate variable for determining whether to prefetch, and if the
queue has overflown, skip the message. In fact, skip the EOF setting and
waking up the decoder thread as well, because the EOF flag should not be
(have been) set in this situation, and waking up the reader thread helps
only if the EOF state changed.
In a shit show of subtle corner case interactions, making the demuxer
cache buffer the entire file can display a small buffered time if
subtitles are enabled. The reason is that some subtitle decoders may
read in advance infinitely, i.e. they read the entire subtitle stream.
Then, since the other streams (audio/video) have logically reached EOF,
and the subtitle stream is set to ds->active==true. This will have to be
fixed properly later to account buffering for subtitle-only files
(another corner case) correctly, but for now this is less annoying.
We don't hope to auto-detect them at load time, as that would be too
much of a pain - even FFmpeg requires fetching and parsing of video
packets, and exposes the information only via deprecated API.
But there still needs to be a way to select them by default. This is
also needed to get the first CC packet at all (without seeking back).
This commit also attempts to clean up locking a bit, which is a PITA,
but it's better be careful & clean.
Even though only 1 seek range is supported at the time.
Other than preparation for possibly future features, the main gain is
actually that we finally separate the reporting for the buffering, and
the seek ranges. These can be subtly different, so it's good to have a
clear separation.
This commit also fixes that the ts_reader wasn't rebased to the start
time, which could make the player show "???" for buffered cache amount
in some .ts files and others (especially at the end, when ts_reader
could become higher than ts_max). It also fixes writing the cache-end
field in the demuxer-cache-state property: it checked ts_start against
NOPTS, which makes no sense.
ts_start was never used (except for the bug mentioned above), so get rid
of it completely. This also makes it convenient to move the segment
check for last_ts to the demux_add_packet() function.
Avoids that cache seeking is not possible with files that have audio
frames with no timestamps (such as avi, sometimes mkv sub-packets from
lacing). These would set back_pts (first seekable PTS) to NOPTS, and
thus disable cache seeking completely. Instead, prune such packets until
we find one with timestamps.
One corner case is that the new next good packet might be in the forward
cache. In this case we defer dropping until the next time this code is
run, and the reader position has possibly moved past the drop point.
In theory, start/ts_min could be set to NOPTS, in which case
"pts < start" for a valid pts would always evaluate to false.
Also remove the redundant "in-cache seek is possible.." message, as
there's always another message when cache seeks are done.
The seek range computation ignored streams with no timestamps. For
things like buffer estimation this is OK and wanted, but the seek range
needs to be conservative.
Which parts of the queue are considered forward or backward cache
depends on ds->reader_header. The packet at ds->reader_head, as well as
all packets following it (via the ->next field) are considered forward.
The fw_packs/fw_bytes/bw_bytes must be updated accordingly.
This broke in demux_add_packet(), when ds->reader_head was _not_ set on
the first packet (or before). This could happen since commit
05ae571241, which can require skipping packets (so they immediately end
up in the backbuffer).
With the timeline code, a packet at the start or end of a segment can
refer to an invisible frame. So it doesn't extend the seek range, and
the timestamp should be clipped to the actual segment range.
Also restructure recompute_keyframe_target_pts() to be hopefully less
confusing.
Restores some behavior from before the demuxer cache changes, though
affects mostly just OSD display. The unknown queue state is reserved for
streams with missing or messed up timestamps.
This fixes .cue files with audio files that contain attached pictures to
some degree. demux_timeline.c just discarded packets with unset index,
so the picture was never fed to the decoder.
Although seeking past the cached range will trigger a low level seek, a
seek into the region between cache end and last video key frame would
simply seek to the video key frame. This meant that you could get
"stuck" at the end of the file instead of terminating playback when
trying to seek past the end.
One change is that we fix this by _actually_ allowing SEEK_FORWARD to
seek past the last video keyframe in find_seek_target().
In that case, or otherwise seeking to cache buffer end, it could happen
that we set ds->reader_head=NULL if the seek target is after the current
packet. We allow this, because the end of the cached region is defined
by the existence of "any" packet, not necessarily a key frame. Seeking
there still makes sense, because we know that there is going to be more
packets (or EOF) that satisfy the seek target.
The problem is that just resuming demuxing with reader_head==NULL will
simply return any packets that come its way, even non-keyframe ones.
Some decoders will produce ugly soup in this case. (In practice, this
was not a problem, because seeking at the end of the cached region was
rare before this commit, and also some decoders like h264 will skip
broken frames by default anyway.)
So the other change of this commit is to enable key frame skipping.
As a nasty implementation detail, we use a separate flag, instead of
setting reader_head to the first key frame encounted (reader_head being
NULL can happen after a normal seek or on playback start, and then we
want to mirror the underlying demuxer behavior, for better or worse).
This change is relatively untested, so you get to keep the pieces for
yourself.
Seems like most code dealing with this was for setting it in redundant
cases. Now SEEK_BACKWARD is redundant, and SEEK_FORWARD is the odd one
out.
Also fix that SEEK_FORWARD was not correctly unset in try_seek_cache().
In demux_mkv_seek(), make the arbitrary decision that a video stream is
not required for the subtitle prefetch logic to be active. We might want
subtitles with long duration even with audio only playback, or if the
file is used as external subtitle.
This improves upon the previous commit, and partially rewrites it (and
other code). It does:
- disable the seeking within cache by default, and add an option to
control it
- mess with the buffer estimation reporting code, which will most likely
lead to funny regressions even if the new features are not enabled
- add a back buffer to the packet cache
- enhance the seek code so you can seek into the back buffer
- unnecessarily change a bunch of other stuff for no reason
- fuck up everything and vomit ponies and rainbows
This should actually be pretty usable. One thing we should add are some
properties to report the proper buffer state. Then the OSC could show a
nice buffer range. Also configuration of the buffers could be made
simpler. Once this has been tested enough, it can be enabled by default,
and might replace the stream cache's byte ringbuffer.
In addition it may or may not be possible to keep other buffer ranges
when seeking outside of the current range, but that would be much more
complex.
More the ignore_eof field to the internal demux_stream struct. This is
relatively messy, because the internal struct exists only once the
stream is created, and after that setting the ignore_eof flag is a race
condition. We could bother with adding demux_add_sh_stream() parameters
for this, but let's not. So in theory a tiny race condition is
introduced, which can never be triggered since all demux API functions
are called by the playback thread only anyway.
Fix that ts_offset is accessed without log (this was introduced much
earlier by myself).
Introduce an alternative way of avoiding the annoying EOF reached
messages by not resetting the EOF flags for CC streams when a CC packet
is added. This makes the second commit in the PR which added the
original fix unnecessary.
As another cosmetic change merge the check in cached_demux_control()
into a single if().
In the future, the CC pseudo-stream should probably be replaced with an
entire pseudo-demuxer or such, which would avoid some of the messiness
(or maybe not, we don't know yet).
As usual, the history of these files is a bit murky. It starts with the
initial commit. (At which some development had already been done,
according to the AUTHORS and ChangeLog files at the time, we should be
but covered with relicensing agreements, though.) then it goes on with
complete lack of modularization, which was cleaned up later (cd68e161).
As usual, we don't consider the copyright of the stuff that has been
moved out cleanly.
There were also contributions to generic code by people who could not be
reached or who did not agree to the relicensing, but this was all
removed.
The only patches that we could not relicense and which were still in the
current code in some form are from Dénes Balatoni: 422b0d2a, 32937181.
We could not reach him, so commits f34e1a0d and 18905298 remove his
additions. It still leaves the demux_control() declaration itself, but
we don't consider it copyrightable. It's basically an idiom that existed
in MPlayer before that change, applied to the demuxer struct. (We even
went as far as making sure to remove all DEMUXER_CTRLs the original
author added.)
Commit be54f481 might be a bit of a corner case, but this was rewritten,
and we consider the old copyright removed long ago.
Similar purpose as f34e1a0dee.
Somehow this is much more natural too, and needs less code.
This breaks runtime updates to duration. This could easily be fixed, but
no important demuxer does this anyway. Only demux_raw and demux_disc
might (the latter for BD/DVD). For the latter it might actually have
some importance when changing titles at runtime (I guess?), but guess
what, I don't care.
This is more uniform, and potentially gets rid of some past copyrights.
It might be that this subtly changes caching behavior (it seems before
this, it synced to the demuxer if the length was unknown, which is not
what we want.)
It's all explained in the DOCS changes. Although this option was always
kind of obscure and pointless. Until it is removed, the only reason for
setting it would be to raise the static default limit, so change its
default to INT_MAX so that it does nothing by default.
Instead of enabling it only when a stream-cache is enabled, also try to
enable it independently from that if the demuxer is marked as
is_network.
Also add some code to the EDL code, so EDLs containing network streams
are automatically cached this way.
Extend the OSD info line so that it shows the demuxer cache in this case
(more or less).
I didn't find where or whether options.rst describes how the demuxer
cache is enabled, so no changes there.
"uncached_stream" is a pretty bad name. It could be mistaken for a
boolean, and then its meaning would be inverted. Rename it.
Also add a "caching" field, which signals that the stream is a cache or
reads from a cache. This is easier to understand and more flexible.
This was excessively useless, and I want my time back that was needed to
explain users why they don't want to use it.
It captured the byte stream only, and even for types of streams it was
designed for (like transport streams), it was rather questionable.
As part of the removal, un-inline demux_run_on_thread() (which has only
1 call-site now), and sort of reimplement --stream-dump to write the
data directly instead of using the removed capture code.
(--stream-dump is also very useless, and I struggled coming up with an
explanation for it in the manpage.)
Disabling cache readahead by default until at least 1 track is selected
is mainly for external files and such, where you don't want them to use
up resources until they're actually used.
It doesn't make sense to disable the cache for the demuxer opened for
prefetch. Also, it's fine to let it do that for the main file too (doing
or not doing it is of little consequence). That saves us from having to
distinguish them.
Cover art handling is a disgusting hack that causes a mess in all
components. And this will stay this way. This is the Xth time I've
changed cover art handling, and that will probably also continue.
But change the code such that cover art is injected into the demux
packet stream, instead of having an explicit special case it in the
decoder glue code. (This is somewhat more similar to the cover art hack
in libavformat.)
To avoid that the over art picture is decoded again on each seek, we
need some additional "caching" in player/video.c. Decoding it after each
seek would work as well, but since cover art pictures can be pretty
huge, it's probably ok to invest some lines of code into caching it.
One weird thing is that the cover art packet will remain queued after
seeks, but that is probably not an issue.
In exchange, we can drop the dec_video.c code, which is pretty
convenient for one of the following commits. This code duplicates a
bunch of lower-level decode calls and does icky messing with this weird
state stuff, so I'm glad it goes away.
It has only 1 caller, and is too far appart within the file. I think it
used to have multiple callers, but now it just doesn't make any sense to
keep it separate anymore.
This deals with the estimation of buffered packets, which is used mostly
for display, but also things like pausing on low buffer levels.
If a stream is fully EOF (no more packets), we don't want to include it
in the total buffer amount. This also means we should make ds->eof less
flaky and more stable, so don't reset it in ds_get_packets() (this
function reset ds->eof just to retrigger a packet read attempt - we can
have this slightly simpler). This somewhat fixes buffering display when
e.g. issuing a refresh seek after re-enabling audio/video when playing
with subtitles only.
When switching a subtitle track, the subtitle wasn't necessarily
updated, especially when playback was paused.
Some awfully subtle and complex interactions here.
First off (and not so subtle), the subtitle decoder will read packets
only on explicit update_subtitles() calls, which, if video is active, is
called only when a new video frame is shown. (A simply video frame
redraw doesn't trigger this.) So call it explicitly. But only if
playback is "initialized", i.e. not when it does initial track selection
and decoder init, during which no packets should be read.
The second issue is that the demuxer thread simply will not read new
packets just because a track was switched, especially if playback is
paused. That's fine, but if a refresh seek is to be done, it really
should do this. So if there's either 1. a refresh seek requested, or 2.
a refresh seek ongoing, then read more packets.
Note that it's entirely possible that we overflow the packet queue with
this in unpredicated weird corner cases, but the queue limit will still
be enforced, so this shouldn't make the situation worse.
Don't access MPOpts directly, and always use the new m_config.h
functions for accessing them in a thread-safe way.
The goal is eventually removing the mpv_global.opts field, and the
demuxer/stream-layer specific hack that copies MPOpts to deal with
thread-safety issues.
This moves around a lot of options. For one, we often change the
physical storage location of options to make them more localized,
but these changes are not user-visible (or should not be). For
shared options on the other hand it's better to do messy direct
access, which is worrying as in that somehow renaming an option
or changing its type would break code reading them manually,
without causing a compilation error.
This is for text subtitles. libavformat currently always reads text
subtitles completely on init. This means the underlying stream is
useless and will consume resources for various reasons (network
connection, file handles, cache memory).
Take care of this by closing the underlying stream if we think the
demuxer has read everything. Since libavformat doesn't export whether it
did (or whether it may access the stream again in the future), we rely
on a whitelist. Also, instead of setting the stream to NULL or so, set
it to an empty dummy stream. This way we don't have to litter the code
with NULL checks.
demux_lavf.c needs extra changes, because it tries to do clever things
for the sake of subtitle charset conversion.
The main reason we keep the demuxer etc. open is because we fell for
libavformat being so generic, and we tried to remove corresponding
special-cases in the higher-level player code. Some of this is forced
due to ass/srt mkv/mp4 demuxing being very similar to external text
files. In the future it might be better to do this in a more
straight-forward way, such as reading text subtitles into libass and
then discarding the demuxer entirely, but for aforementioned reasons
this could be more of a mess than the solution introduced by this
commit.
Probably fixes#3456.
Cleaner and makes it easier to change the underlying stream.
mp_property_stream_capture() still directly accesses it directly via
demux_run_on_thread(). This is evil, but still somewhat sane and is not
getting into the way here.
Not sure if I got all field accesses.
It doesn't necessarily have to mean anything bad.
We're still too lazy to provide any more detailed information (e.g.
whether this happened to likely bad interleaving, excessive amount of
packets like with some ASS subs, or that the readahead user option is
limitted by the packet queue size).
When an ogg track upodates metadata, we have to perform a complicated
runtime update due to the demux.c architecture. A detail was broken and
an array was allocated with the previous number of streams, which
usually led to invalid memory write accesses at least on the first
update.
See github commit comment on commit b9ba9a89.
If the PEAK tag is invalid, return an error.
Make the error signalling conventions more uniform by strictly returning
a negative value on error, and treating >=0 as success.
The demuxer layer usually doesn't log per-stream information, and even
the replaygain information was logged only if it came from tags.
So log it in af_volume instead.
...and ignore it. The main purpose is for retrieving per-track
replaygain tags. Other than that per-track tags are not used or accessed
by the playback core yet.
The demuxer infrastructure is still not really good with that whole
synchronization thing (at least in part due to being inherited from
mplayer's single-threaded architecture). A convoluted mechanism is
needed to transport the tags from demuxer thread to user thread. Two
factors contribute to the complexity: tags can change during playback,
and tracks (i.e. struct sh_stream) are not duplicated per thread.
In particular, we update the way replaygain tags are retrieved. We first
try to use per-track tags (common in Matroska) and global tags
(effectively formats like mp3). This part fixes#3405.
Remove the explicit whitelisting of formats for refresh seeks. Instead,
check whether the packet position is somewhat reliable during demuxing.
If there are packets without position, or the packet position is not
monotonically increasing, then do not use them for refresh seeks.
This does not make sure of some requirements, such as deterministic
seeks. If that happens, mpv will mess up a bit on stream switching.
Also, add another method that uses DTS to identify packets, and prefer
it to the packet position method. Even if there's a demuxer which
randomizes packet positions, it hardly can do that with DTS. The DTS
method is not always available either, though. Some formats do not have
a DTS, and others are not always strictly monotonic (possibly due to
libavformat codec parsing and timestamp determination issues).
If the packet read function returns, and EOF was detected, and a seek
was issued in the meantime, then don't use the EOF result. The seek will
be processed later, and reset the EOF state anyway.
The main effect is probably that we don't return EOF to the decoders
(which the playback core resets before issuing the seek), and that we
won't log an EOF message.
Not important, but slightly more correct.
When switching tracks, we normally have the problem that data gets lost
due to readahead buffering. (Which in turn is because we're stubborn and
instruct the demuxers to discard data on unselected streams.) The
demuxer layer has a hack that re-reads discarded buffered data if a
stream is enabled mid-stream, so track switching will seem instant.
A somewhat similar problem is when all tracks of an external files were
disabled - when enabling the first track, we have to seek to the target
position.
Handle these with the same mechanism. Pass the "current time" to the
demuxer's stream switch function, and let the demuxer figure out what to
do. The demuxer will issue a refresh seek (if possible) to update the
new stream, or will issue a "normal" seek if there was no active stream
yet.
One case that changes is when a video/audio stream is enabled on an
external file with only a subtitle stream active, and the demuxer does
not support rrefresh seeks. This is a fuzzy case, because subtitles are
sparse, and the demuxer might have skipped large amounts of data. We
used to seek (and send the subtitle decoder some subtitle packets
twice). This case is sort of obscure and insane, and the fix would be
questionable, so we simply don't care.
Should mostly fix#3392.
Instead of having a separate for each, which also requires separate
additional caching in the demuxer. (The demuxer adds an indirection,
since STREAM_CTRLs are not thread-safe.)
Since this includes the cache speed, this should fix#3003.
This is simpler, because it doesn't have to wait from both threads for
synchronization.
Apart from being simpler/cleaner, this serves vague plans to stop/start
the demuxer thread itself automatically on demand (for the purpose of
reducing unneeded resource usage).
This pause stuff is bothersome and is needed only for a few corner-
cases. This commit removes it from the demuxer public API and replaces
it with a demux_run_on_thread() function and refactors the code which
needed demux_pause(). The next commit will change the implementation.
Commit 503c6f7f essentially removed timestamps from "laces" (Block sub-
divisions), which means many audio packets will have no timestamp.
There's no reason why bitrate calculation can't just delayed to a point
when the next timestamp is known.
Fixes#2903 (no audio bitrate with mkv files).
Ever since a change in mplayer2 or so, relative seeks were translated to
absolute seeks before sending them to the demuxer in most cases. The
only exception in current mpv is DVD seeking.
Remove the SEEK_ABSOLUTE flag; it's not the implied default. SEEK_FACTOR
is kept, because it's sometimes slightly useful for seeking in things
like transport streams. (And maybe mkv files without duration set?)
DVD seeking is terrible because DVD and libdvdnav are terrible, but
mostly because libdvdnav is terrible. libdvdnav does not expose seeking
with seek tables. (Although I know xbmc/kodi use an undocumented API
that is not declared in the headers by dladdr()ing it - I think the
function is dvdnav_jump_to_sector_by_time().) With the current mpv
policy if not giving a shit about DVD, just revert our half-working seek
hacks and always use dvdnav_time_search(). Relative seeking might get
stuck sometimes; in this case --hr-seek=always is recommended.
If a stream is marked as EOF (due to no packets found in reach), then we
need to wakeup the decoder. This is important especially if no packets
are found at the start of the file, so the A/V sync logic actually
starts playback, instead of waiting for packets that will never come.
(It would randomly start playback when running the playback loop due to
arbitrary external events like user input.)
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.
Slightly helps with timeline stuff, like EDL. There is no need to keep
network (or even just disk I/O) busy for all segments at the same time,
because 1. the data won't be needed any time soon, and 2. will probably
be discarded anyway if the stream is seeked when segment is resumed.
Partially fixes#2692.
This is mainly a refactor. I'm hoping it will make some things easier
in the future due to cleanly separating codec metadata and stream
metadata.
Also, declare that the "codec" field can not be NULL anymore. demux.c
will set it to "" if it's NULL when added. This gets rid of a corner
case everything had to handle, but which rarely happened.
This slightly changes behavior when seeking with external audio/subtitle
tracks if transport streams and mpeg files are played, as well as
behavior when seeking with such external tracks.
get_main_demux_pts() is evil because it always blocks on the demuxer (if
there isn't already a packet queued). Thus it could lock up the player,
which is a shame because all other possible causes have been removed.
The reduced "precision" when seeking in the ts/mpeg cases (where
SEEK_FACTOR is used, resulting in byte seeks instead of timestamp seeks)
might lead to issues. We should probably drop this heuristic. (It was
introduced because there is no other way to seek in files with PTS
resets with libavformat, but its value is still questionable.)
Slightly change how it is decided when a new packet should be read.
Switch to demux_read_packet_async(), and let the player "wait properly"
until required subtitle packets arrive, instead of blocking everything.
Move distinguishing the cases of passive and active reading into the
demuxer, where it belongs.
The demuxer infrastructure was originally single-threaded. To make it
suitable for multithreading (specifically, demuxing and decoding on
separate threads), some sort of tripple-buffering was introduced. There
are separate "struct demuxer" allocations. The demuxer thread sets the
state on d_thread. If anything changes, the state is copied to d_buffer
(the copy is protected by a lock), and the decoder thread is notified.
Then the decoder thread copies the state from d_buffer to d_user (again
while holding a lock). This avoids the need for locking in the
demuxer/decoder code itself (only demux.c needs an internal, "invisible"
lock.)
Remove the streams/num_streams fields from this tripple-buffering
schema. Move them to the internal struct, and protect them with the
internal lock. Use accessors for read access outside of demux.c.
Other than replacing all field accesses with accessors, this separates
allocating and adding sh_streams. This is needed to avoid race
conditions. Before this change, this was awkwardly handled by first
initializing the sh_stream, and then sending a stream change event. Now
the stream is allocated, then initialized, and then declared as
immutable and added (at which point it becomes visible to the decoder
thread immediately).
This change is useful for PR #2626. And eventually, we should probably
get entirely of the tripple buffering, and this makes a nice first step.
All of these are supported by FFmpeg now. It was disabled by default
too (with FFmpeg).
If compiled against Libav, mpv will lose the ability to read some
subtitle formats (but the most important ones, srt and ass, still should
work).
Most of this is explained in the DOCS additions.
This gives us slightly more sanity, because there is less interaction
between the various parts. The goal is getting rid of the video_offset
entirely.
The simplification extends to the user API. In particular, we don't need
to fix missing parts in the API, such as the lack for a seek command
that seeks relatively to the start time. All these things are now
transparent.
(If someone really wants to know the real timestamps/start time, new
properties would have to be added.)
This loaded external .ass files via libass. libavformat's .ass reader is
now good enough, so use that instead.
Apparently libavformat still doesn't support fonts embedded into text
.ass files, but support for this has been accidentally broken in mpv for
a while anyway. (And only 1 person complained.)
This makes the bitrate properties unavailable, instead of
returning 0 when:
1. No track is selected, or
2. Not enough packets have been read to have a bitrate estimate yet
Make handling of metadata slightly more generic, and add reading of the
"PERFORMER" fields. There are some more fields, but for now let's leave
it at this.
TRACK-specific PERFORMER fields have to be read from the per-chapter
metadata (somewhat obscure).
Fixes#2328.
This works similar to the existing .rar support, but uses libarchive.
libarchive supports a number of formats, including zip and (most of)
rar.
Unfortunately, seeking does not work too well. Most libarchive readers
do not support seeking, so it's emulated by skipping data until the
target position. On backwards seek, the file is reopened. This works
fine on a local machine (and if the file is not too large), but will
perform not so well over network connection.
This is disabled by default for now. One reason is that we try
libarchive on every file we open, before trying libavformat, and I'm not
sure if I trust libarchive that much yet. Another reason is that this
breaks multivolume rar support. While libarchive supports seeking in
rar, and (probably) supports multivolume archive, our support of
libarchive (probably) does not. I don't care about multivolume rar, but
vocal users do.
Instead, force everyone to use the metadata struct and set a "title"
field. This is only a problem for the timeline producers, which set up
chapters manually. (They do this because a timeline is a separate
struct.)
This fixes the behavior of the chapter-metadata property, which never
returned a "title" property for e.g. ordered chapters.
Add --demuxer-max-packets and --demuxer-max-bytes, which control the
maximum size of the packet queue. These can be helpful to avoid
excessive memory usage.
Memory usage is the reason why there's a limit in the first place. If a
file is more or less broken, and audio and video don't line up, the
decoders will fill up the packet queue trying to read more audio or
video, and the maximum sizes are required to avoid unbounded memory
allocation. Being able to override the maximum sizes is useful; either
for restricting memory usage further, or enlarging the sizes when
attempting to play various broken files.
Remove --demuxer-readahead-packets and --demuxer-readahead-bytes. These
were a bit useless. They could force a minimum packet queue size, but
controlling the queue size with --demuxer-readahead-secs is much nicer.
It's fairly certain nobody ever used these options.
Instead of opening a stream and then a demuxer, do both at once with
demux_open_url().
This requires some awkward additions to demuxer_params, because there
are some weird features associated with opening the main file. E.g. the
relatively useless --stream-capture features requires enabling capturing
on the stream before the demuxer is opened, but on the other hand
shouldn't be done on secondary files like external subtitles.
Also relatively bad: since demux_open_url() returns just a demuxer
pointer or NULL, additional error reporting is done via demuxer_params.
Still, at least conceptually, it's ok, and simpler than before.
Nobody wanted to restore this, so it gets the boot.
If anyone still wants to volunteer to restore menu support, this would
be welcome. (I might even try it myself if I feel masochistic and like
wasting a lot of time for nothing.) But if it does get restored, it
should be done differently. There were many stupid things about how it
was done. For example, it somehow tried to pull mp_nav_events through
all the layers (including needing to "buffer" them in the demuxer),
which was needlessly complicated. It could be done simpler.
This code was already inactive, so this commit actually changes nothing.
Also keep in mind that normal DVD/BD playback still works.
Until now, if a stream wasn't seekable, but the stream cache was enabled
(--cache), we've enabled seeking anyway. The idea was that at least
short seeks would typically fall within the cache. And if not, the user
was out of luck and terrible things happened. In other words, it was
unreliable.
Be stricter about it and remove this behavior. Effectively, this will
for example disable seeking in piped data.
Instead of trying to be clever, add an --force-seekable option, which
will always enable seeking if the user really wants it.
This reads the "CUESHEET" tag, and attempts to parse it as .cue data. If
any is found, the cue tracks are added as chapters.
This reuses the parser written for demux_cue.c.
Fixes#1957.
The options don't change, but they're now declared and used privately by
demux_mkv.c. This also brings with it a minor refactor of the subpreroll
seek handling - merge the code from playloop.c into demux_mkv.c. The
change in demux.c is pretty much equivalent as well.
On EOF, this stopped reporting the actual cache duration, and just
signalled unknown duration. Fix this and keep reporting whatever is left
in the packet queue.
This reverts commit 5438a8b3. The commit doesn't give a good explanation
as to why it is needed, but I guess it was because the reporting was
imperfect (it switched between unknown or 0, and the correct duration).
This also removes a line added in commit 848546f2. The line is
ds->active = false;
The "active" flag basically says that data from this stream is actively
needed, and it's used to calculate the minimum data that can actually be
played (approximately). If this were ignored, a sparse subtitle stream
would set the cache duration to 0s. The commit message adding the line
says "actually does nothing, but in theory it's cleaner". Well, screw
it.
With a recent cleanup, rar support was stuffed into demux_playlist.c
(because "opening" rar files pretty much just lists archive contents and
adds them to a playlist using a special rar:// protocol, which will
actually access the rar file contents).
Since demux_playlist.c is probed _after_ demux_lavf.c (and should/must
be), libavformat was given the chance to detect DTS streams embedded
within the rar file. This is not really what we want, and a regression
what happened before rar listing was moved to demux_playlist.c.
Fix it by moving the rar listing into its own pseudo-demuxer, and let ir
probe before demux_lavf.c.
(Yes, this feature still has users.)
Check async abort notification. libavformat already do something
equivalent.
Before this commit, the demuxer could enter resync mode (and print silly
warning messages) when the stream stopped returning data because of an
abort.
Includes some logic for not starting the demuxer thread for fully read
subtitles. (Well, the cache will still waste _lots_ of resources, and
the cache always has to be created, because we don't know whether it'll
be needed _before_ opening the file.)
See #1597.
The Matroska timeline code was the only thing which still used the
demuxer.type field. This field explicitly identifies a demuxer
implementation. The purpose of the Matroska timeline code was to reject
files that are not Matroska. But it already forces the Matroska format,
meaning loading will explicitly only use the Matroska demuxer. If the
demuxer can't open the file, no other demuxer will be tried, and thus
checking the field is redundant.
The change in demux_mkv_timeline.c removes the if condition, and
unindents the if body.
Only demux_cue and demux_edl used it. It's a weird field and doesn't
help with anything anymore - by now, it only saves a priv context in the
mentioned demuxers. Reducing the number of confusing things the demuxer
struct has is more important than minimizing the code.
If the previous subtitle packet is too far back, and the refresh seek
won't pick it up, and the packet never comes again. As a consequence,
the refresh mode was never stopped on the subtitle stream, which caused
all packets to be discarded.
Fix by assuming the file position is monotonically increasing; then it
will resume even if a packet _after_ the intended resume point is
returned. This introduces a new requirement on how the demuxer behaves.
(I'm not sure if mp4 actually satisfies this requirement in all cases.)
Fixes a regression introduced by commit f9f2e1cc.
This removes the delay when switching audio tracks in mkv or mp4 files.
Other formats are not enabled, because it's not clear whether the
demuxers fulfill the requirements listed in demux.h. (Many formats
definitely do not with libavformat.)
Background:
The demuxer packet cache buffers a certain amount of packets. This
includes only packets from selected streams. We discard packets from
other streams for various reasons. This introduces a problem: switching
to a different audio track introduces a delay. The delay is as big as
the demuxer packet cache buffer, because while the file was read ahead
to fill the packet buffer, the process of reading packets also discarded
all packets from the previously not selected audio stream. Once the
remaining packet buffer has been played, new audio packets are available
and you hear audio again.
We could probably just not discard packets from unselected streams. But
this would require additional memory and CPU resources, and also it's
hard to tell when packets from unused streams should be discarded (we
don't want to keep them forever; it'd be a memory leak).
We could also issue a player hr-seek to the current playback position,
which would solve the problem in 1 line of code or so. But this can be
rather slow.
So what we do in this commit instead is: we just seek back to the
position where our current packet buffer starts, and start demuxing from
this position again. This way we can get the "past" packets for the
newly selected stream. For streams which were already selected the
packets are simply discarded until the previous position is reached
again.
That latter part is the hard part. We really want to skip packets
exactly until the position where we left off previously, or we will skip
packets or feed packets to the decoder twice. If we assume that the
demuxer is deterministic (returns exactly the same packets after a seek
to a previous position), then we can try to check whether it's the same
packet as the one at the end of the packet buffer. If it is, we know
that the packet after it is where we left off last time.
Unfortunately, this is not very robust, and maybe it can't be made
robust. Currently we use the demux_packet.pos field as unique packet
ID - which works fine in some scenarios, but will break in arbitrary
ways if the basic requirement to the demuxer (as listed in the demux.h
additions) are broken. Thus, this is enabled only for the internal mkv
demuxer and the libavformat mp4 demuxer.
(libavformat mkv does not work, because the packet positions are not
unique. Probably could be fixed upstream, but it's not clear whether
it's a bug or a feature.)
If a file is unseekable (consider e.g. a http server without resume
functionality), but the stream cache is active, the player will enable
seeking anyway. Until know, client API user couldn't know that this
happens, and it has implications on how well seeking will work. So add a
property which exports whether this situation applies.
Fixes#1522.
Pass through the seek flags to the stream layer. The STREAM_CTRL
semantics become a bit awkward, but that's still the least awkward
part about optical disc media.
Make demux_disc.c request relative seeks. Now the player will use
relative seeks if the user sends relative seek commands, and the
demuxer announces it wants these by setting rel_seeks to true. This
change probably changes seek behavior for dvd, dvdnav, bluray, cdda,
and possibly makes seeking useless if the demuxer-cache is set to
a high value.
Will be used in the next commit. (Split to make reverting the next
commit easier.)
Normally the player doesn't read from unselected streams, so this should
be a no-op. But unfortunately, some broken files can severely confuse
the player, and assign the same demuxer stream to multiple front-end
tracks. Then selecting one of the tracks would deselect the other track,
with the end result that the demuxer stream for the selected track is
deselected. This could happen with mkv files that use the same track
number (which is of course broken). timeline_set_part() sets the tracks
using demuxer_stream_by_demuxer_id(), using the broken non-unique IDs.
The observable effect was that the player never quit, because
demux_read_packet_async() told the caller to wait some longer for new
packets. Fix by returning EOF instead.
Fixes#1481.
There's no reason why parts of this demuxer would be in a separate
source file. The existence of this code is already somewhat questionable
anyway, so it may as well be dumped into a single file.
Even stranger that demux.c included mf.h for no reason (it was an
artifact from 2002 when the architecture was uncleaner).
This message was added in commit a0acb6ea. But it showed up in all sorts
of inappropriate contexts, such as when opening m3u from an unseekable
http URL, or playing DVDs. So I guess this didn't work out. Disabling it
again.
This was completely breaking any low-level caching. Change it so that at
least demuxer caching will work.
Do this by using the metadata cache mechanism to funnel through the menu
commands.
For some incomprehensible reason, I had to reorder the events (which
affects their delivery priority), or they would be ignored. Probably
some crap about the event state being cleared before it could be
delivered. I don't give a shit.
All this code sucks. It would probably be better to let discnav.c access
the menu event "queue" directly, and to synchronize access with a mutex,
instead of going through all the caching layers, making things
complicated and slow.
This was removed in commit 480f82fa. This caused the cache display not
to update while paused, because the update_cache() function is never
called in the thread (now I remember why the extra call was "needed").
The old implementation intentionally run update_cache() only before
waiting on a mutex, with no further checks for the condition variable.
In theory, this is strictly not sane, but since it was just for the
retrieval of the very fuzzy cache status, it was ok. Now we want to call
update_cache() outside of the mutex though - which means that in order
to avoid missed wakeups, a proper condition has to be used.
If no packets are queued, the readahead time is obviously 0.
If the end time is smaller than the start time, the problem is probably
that audio and video start at slightly different times - report 0 in
this case too.
Do this because seeing "???" as readahead time is a bit annoying.
This influences the demuxer readahead display. If a stream has reached
EOF, we want to ignore it for the purpose of this calculation.
Note that if a stream contains no packets, it still should cause the
value 0s to be displayed (unless it's EOF), because that's just the
actual situation.
This was relying on the fact that timestamps will always be numerically
larger than MP_NOPTS_VALUE, but the trick didn't actually work for
MP_PTS_MIN. Be a bit more sincere, and don't rely on this anymore. This
fixes the comparison, and avoids the readahead amount displaying as
"???" in some situations (since one of the values was NOPTS).
In this case, we didn't find any new packets for this stream, even
though we've read ahead as much as possible. (If reading ahead in this
case, the "Too many packets in the demuxer packet queues" error is
normally printed.)
If we do consider this an underrun, handle_pause_on_low_cache() will
pause and show the "buffering" state, which is not useful.
Could also happen on very bad interleaving.
Instead of defining a separate data structure in the core.
For some odd reason, demux_chapter exported the chapter time in
nano-seconds. Change that to the usual timestamps (rename the field
to make any code relying on this to fail compilation), and also remove
the unused chapter end time.
This was originally done for DVD/BD/DVB, where the start position could
be something different from 0, and seeking back to 0 would mess it up
completely.
Since we're not quite sure that these streams are unseekable, we can
simplify this somewhat, and also make sure we also start at 0 for normal
files. Helps a little bit with the following edition reloading commit.
