The if branch has a weak check to test whether the codec_id is the short
ID, and handles the long IDs in the else branch. The long IDs are all
longer than 12 bytes long, so hardcoding the string offset to get the
trailing part of the name makes sense. But the if condition checks for
another thing, which could get the else branch run even if the codec_id
is short.
Fix the bogus control flow and check if the codec_id is long enough. One
of these checks could be considered redundant, but include them both for
defensive coding.
Do a minimal check on data read with stream_peek(). This could help with
probing from unseekable streams in some situations. (We could check the
entire EBML and Matroska headers, but probably not worth the trouble. We
could also seek back to the start, which demux.c doesn't do, but which
would work usually - also not worth the trouble.)
Make the changes started in commit c827ae5f more eloborate, and provide
an option to control the amount of data read before the seek-target. To
achieve this, rewrite the loop that finds the lowest still acceptable
target cluster. It is now searched by time instead of file position. The
behavior (both with and without preroll option) may be different from
before this change, although it shouldn't be worse.
The change demux_mkv_read_cues() fixes a bug: when seeking after playing
normally, the code would erroneously assume that durations are set. This
doesn't happen if the first operation after loading was a seek instead
of playback.
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.
Revert commit 24e52f66; even though the old beheavior doesn't make sense
(as the commit message assured), it turns out that this works better:
typically, it means preroll will start from the previous video key frame
(the video CUE index will contain clusters with video key frames only),
which often coincides with subtitle changes. Thus the old behavior is
actually better.
Change the code that uses CueDuration elements. Instead of merely
checking whether preroll should be done, find the first cluster that
needs to be read to get all subtitle packets. (The intention is to
compensate for the enlarged preroll cluster-range due to reverting
commit 24e52f66.)
Found by clang sanitizer. Casting unsigned integers to signed integers
with same size has implementation defined behavior (it's even allowed to
crash), but it seems reasonable to expect that reasonable
implementations do a complement of 2 "conversion".
This considered only index entries that were for the same track ID as
the track used for seeking. This doesn't make much sense for preroll;
it'll just possibly skip clusters, and select an earlier cluster.
One possible negative side-effect is that the preroll might be too tight
now, and miss subtitle packets more often.
The demuxer has a hack to seek to the cluster before the target cluster
in order to "catch" subtitle lines that start before the seek target,
but overlap with the video after the seek target.
Avoid this hack if the cue index indicates that there are no overlapping
subtitle packets that can be caught by seeking to the previous cluster.
Nothing is done with them yet. This is preparation for the following
commit.
CueRelativePosition isn't even saved anywhere, because I don't intend to
use it. (Too messy for no gain.)
Instead of indexing only 1 packet per cluster (which is enough for
working seeking), add every packet to the index.
Since on seek, we go through every single index entry, this probably
makes seeking slower. On the other hand, this code is used for files
without index only (e.g. incomplete files), so it probably doesn't
matter much.
Preparation for the following commits.
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.
This mechanism was introduced for Opus, and allows correct skipping of
"preroll" data, as well as discarding trailing audio if the file's
length isn't a multiple of the audio frame size.
Not sure how to handle seeking. I don't understand the purpose of the
SeekPreRoll element.
This was tested with correctness_trimming_nobeeps.opus, remuxed to mka
with mkvmerge v7.2.0. It seems to be correct, although the reported file
duration is incorrect (maybe a mkvmerge issue).
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.
Basically, this will mark the demuxer as seekable with rtmp* and mmsh
protocols. These protocols have network-level time seeking, and whether
you can seek on the byte level does not matter.
Until now, seeking was typically only enabled because of the cache, and
a (nonsensical) warning was shown accordingly.
It still could happen that the server doesn't actually support thse
requests (or simply rejects them), so this is somewhat imperfect.
I'm not sure if this could be done in libavformat instead. Probably not,
because libavformat doesn't seem to have any mechanism for trying one
protocol and reverting (or redirecting) to another one if needed.
This commit is sort of a hack too, because it redirects the URL by
pretending the http:// link is a playlist containing the mmsh:// link.
The list of mime types is borrowed from MPlayer (which has completely
different code to handle this).
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.
Although this is fine when the stream cache is active (which caches
these and returns the result immediately), it seems cleaner not to
rely on this detail.
Remove the update_cache() call from demux_thread(), because it's sort
of in the way. I forgot why it exists, and there's probably no good
reason for it to exist anyway.
It's needed for some obscure feature in combination with .rar reading.
However, it's unconditionally used by the subtitle loader code, so take
care of not blocking the main thread unnecessarily.
(Untested.)
Apparently using the stream index is the best way to refer to the same
streams across multiple FFmpeg-using programs, even if the stream index
itself is rarely meaningful in any way.
For Matroska, there are some possible problems, depending how FFmpeg
actually adds streams. Normally they seem to match though.
Especially with other components (libavcodec, OSX stuff), the thread
list can get quite populated. Setting the thread name helps when
debugging.
Since this is not portable, we check the OS variants in waf configure.
old-configure just gets a special-case for glibc, since doing a full
check here would probably be a waste of effort.
Normally, we pass libavformat demuxers a wrapped mpv stream. But in some
cases, such as HLS and RTSP, we let libavformat open the stream itself.
In these cases, set typical network properties like useragent according
to the mpv options.
(We still don't set it for the cases where libavformat opens other
streams on its own, e.g. when opening the companion .sub file for .idx
files - not sure if we maybe should always set these options.)
Fixes opening some streams.
This means the HLS playlist will be opened twice, but that's not much of
a problem, considering it's pretty small, and HLS will make many other
http accesses anyway.
The one in msg.c was mistakenly removed with commit e99a37f6.
I didn't actually test the change in ao_sndio.c (but obviously "ap"
shouldn't be static).
Commit 50e131b43e happened to make it work for DVD (because the higher
bits of the ID are masked in the DVD case), but failed for Bluray. This
probably fixes it, although I don't have a sample to multiple streams to
confirm it really does it right.
CC: @mpv-player/stable
This code meant to flush demuxer internal buffers by doing a byte seek
to the current position. In theory this shouldn't drop any stream data.
However, if the stream positions mismatch, then avio_seek() (called by
av_seek_frame()) stops being a no-op, and might for example read some
data to skip to the seek target. (This can happen if the distance is
less than SHORT_SEEK_THRESHOLD.)
The positions get out of sync because we drop data at one point (which
is what we _want_ to do). Strictly speaking, the AVIOContext flushing is
done incorrectly, becuase pb->pos points to the start of the buffer, not
the current position. So we have to increment pb->pos by the buffered
amount.
Since there are other weird reasons why the positions might go out of
sync (such as stream_dvd.c dropping buffers itself), and they don't
necessarily need to be in sync in the first place unless AVIOContext has
nothing buffered internally, just use the sledgehammer approach and
correct the position manually.
Also run av_seek_frame() after this. Currently, it shouldn't read
anything, but who knows how that might change with future libavformat
development.
This whole change didn't have any observable effect for me, but I'm
hoping it fixes a reported problem.
When flushing the AVIOContext, make sure it can't seek back to discarded
data. buf_ptr is just the current read position, while buf_end - buffer
is the actual buffer size. Since mpegts.c is littered with seek calls,
it might be that the ability to seek could read
Mark the stream (which the demuxer uses) as not seekable. The cache can
enable seeking again (this behavior is sometimes useful for other
things). I think this should have had no bad influence in theory, since
seeking BD/DVD first does the "real" seek, then flushes libavformat and
reads new packets.
Makes it behave slightly better for VP9. This is also the behavior
libavformat has.
Also while we're at it, don't set duration except for the first packet.
Normally we don't use the duration except for subtitles (which are never
parsed or "laced"), so this should make no observable difference.
wm4