The libavformat API is not suitable for exporting output devices as muxers.
Some practical problems are e.g. lack of timing/synchronization mechanisms
or interaction with output-specific features.
This does not trigger any warnings, but adds robustness.
Reviewed-by: Nicolas George <george@nsup.org>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Current implementation didn't include duration of
last processed packet.
Device may return negative timestamps without
this correction.
Signed-off-by: Lukasz Marek <lukasz.m.luki@gmail.com>
In testing, the file output plugin gave a max buffer size of about 20 million
frames, which is way more than what is really needed and causes a memory
allocation error on my system.
The PTS for captured audio was measured using snd_pcm_htimestamp.
snd_pcm_htimestamp hangs when the input is a dsnoop plugin.
Furthermore, at some point, snd_pcm_htimestamp started returning monotonic
timestamps rather than wall clock timestamps, in most but not all
situations.
Monotonic timestamps are fine, but ffmpeg uses wall clock timestamps
everywhere else, and we have no API to inform the user which kind of
timestamps it is.
A separate snd_pcm_htimestamp is only slightly less accurate than
snd_pcm_htimestamp: the standard deviation for the difference between two
consecutive timestamps is (on my hardware):
- ~13 µs with snd_pcm_htimestamp;
- ~35 µs with av_gettime;
- ~5 µs with av_gettime and a timefilter.
Currently quad, 5.0, 5.1 and 7.1 are implemented.
Implementing support for other formats/layouts and capture should be
straightforward.
5.0 and 7.1 support by Carl Eugen Hoyos.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Currently, only S16 quad, 5.1 and 7.1 are implemented.
Implementing support for other formats/layouts and capture should be
straightforward.
7.1 support by Carl Eugen Hoyos.
Passing an explicit filename to this command is only necessary if the
documentation in the @file block refers to a file different from the
one the block resides in.
Originally committed as revision 22921 to svn://svn.ffmpeg.org/ffmpeg/trunk
Otherwise doxygen complains about ambiguous filenames when files exist
under the same name in different subdirectories.
Originally committed as revision 16912 to svn://svn.ffmpeg.org/ffmpeg/trunk
Patch by Nicolas George: name surname normalesup org
Original thread: [FFmpeg-devel] [PATCH] ALSA for libavdevice
Date: 12/09/2008 07:17 PM
Originally committed as revision 16800 to svn://svn.ffmpeg.org/ffmpeg/trunk
Carl Eugen Hoyos
Diego Biurrun
Ganesh Ajjanagadde
Lukasz Marek
Lukasz Marek
Anton Khirnov
Nicolas George
Michael Niedermayer
Justin Ruggles
Stefano Sabatini
Mans Rullgard
Carl Eugen Hoyos
Nicolas George