Currently, AVStream contains an embedded AVCodecContext instance, which
is used by demuxers to export stream parameters to the caller and by
muxers to receive stream parameters from the caller. It is also used
internally as the codec context that is passed to parsers.
In addition, it is also widely used by the callers as the decoding (when
demuxer) or encoding (when muxing) context, though this has been
officially discouraged since Libav 11.
There are multiple important problems with this approach:
- the fields in AVCodecContext are in general one of
* stream parameters
* codec options
* codec state
However, it's not clear which ones are which. It is consequently
unclear which fields are a demuxer allowed to set or a muxer allowed to
read. This leads to erratic behaviour depending on whether decoding or
encoding is being performed or not (and whether it uses the AVStream
embedded codec context).
- various synchronization issues arising from the fact that the same
context is used by several different APIs (muxers/demuxers,
parsers, bitstream filters and encoders/decoders) simultaneously, with
there being no clear rules for who can modify what and the different
processes being typically delayed with respect to each other.
- avformat_find_stream_info() making it necessary to support opening
and closing a single codec context multiple times, thus
complicating the semantics of freeing various allocated objects in the
codec context.
Those problems are resolved by replacing the AVStream embedded codec
context with a newly added AVCodecParameters instance, which stores only
the stream parameters exported by the demuxers or read by the muxers.
* qatar/master:
rtpdec: Templatize the code for different g726 bitrate variants
rv40: move loop filter to rv34dsp context
lavf: make av_set_pts_info private.
rtpdec: Add support for G726 audio
rtpdec: Add an init function that can do custom codec context initialization
avconv: make copy_tb on by default.
matroskadec: don't set codec timebase.
rmdec: don't set codec timebase.
avconv: compute next_pts from input packet duration when possible.
lavf: estimate frame duration from r_frame_rate.
avconv: update InputStream.pts in the streamcopy case.
Conflicts:
avconv.c
libavdevice/alsa-audio-dec.c
libavdevice/bktr.c
libavdevice/fbdev.c
libavdevice/libdc1394.c
libavdevice/oss_audio.c
libavdevice/v4l.c
libavdevice/v4l2.c
libavdevice/vfwcap.c
libavdevice/x11grab.c
libavformat/au.c
libavformat/eacdata.c
libavformat/flvdec.c
libavformat/mpegts.c
libavformat/mxfenc.c
libavformat/rtpdec_g726.c
libavformat/wtv.c
libavformat/xmv.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
presets: rename presets directory
lavc: make avcodec_get_context_defaults3 "officially" public
lavf: replace av_new_stream->avformat_new_stream part II.
lavf,lavd: replace av_new_stream->avformat_new_stream part I.
lavf: add avformat_new_stream as a replacement for av_new_stream.
Use correct scaling table for bwd-pred MVs in second B-field
Ut Video decoder
Makefile: change presets extension to .avpreset
lavfi: add rgbtestsrc source, ported from MPlayer libmpcodecs
lavfi: add testsrc source
AVOptions: add documentation.
presets: update libx264 ffpresets
Conflicts:
Changelog
doc/APIchanges
doc/ffmpeg.texi
ffpresets/libx264-ipod320.ffpreset
ffpresets/libx264-ipod640.ffpreset
ffserver.c
libavcodec/avcodec.h
libavcodec/options.c
libavcodec/version.h
libavdevice/libdc1394.c
libavfilter/avfilter.h
libavfilter/vsrc_testsrc.c
libavformat/flvdec.c
libavformat/riff.c
libavformat/version.h
libavformat/wtv.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
Fix NASM include directive
dsputil_mmx: Honor HAVE_AMD3DNOW
lavf,lavd: remove all usage of AVFormatParameters from demuxers.
jack: add 'channels' private option.
VC-1: fix reading of custom PAR.
Remove redundant and dubious video codec detection by its extradata
mpeg12: remove repeat-field code disabled since May 2002
patch checklist: suggest fate instead of regression tests
Turn on resampling on sudden size change instead of bailing out during recode.
avtools: reinitialise filter chain when input video stream changes dimensions
Conflicts:
Makefile
avconv.c
doc/developer.texi
ffplay.c
libavcodec/x86/dsputil_mmx.c
libavdevice/libdc1394.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
AVFormatParameters are converted into corresponding private options in
av_open_input_file/stream() compat wrappers, so accessing them from
demuxers is redundant.
* qatar/master: (32 commits)
doc: create separate section for audio encoders
swscale: Remove orphaned, commented-out function declaration.
swscale: Eliminate rgb24toyv12_c() duplication.
Remove h263_msmpeg4 from MpegEncContext.
APIchanges: Fill in git hash for fps_probe_size (30315a8)
avformat: Add fpsprobesize as an AVOption.
avoptions: Return explicitly NAN or {0,0} if the option isn't found
rtmp: Reindent
rtmp: Don't try to do av_malloc(0)
tty: replace AVFormatParameters.sample_rate abuse with a private option.
Fix end time of last chapter in compute_chapters_end
ffmpeg: get rid of useless AVInputStream.nb_streams.
ffmpeg: simplify managing input files and streams
ffmpeg: purge redundant AVInputStream.index.
lavf: deprecate AVFormatParameters.channel.
libdc1394: add a private option for channel.
dv1394: add a private option for channel.
v4l2: reindent.
v4l2: add a private option for channel.
lavf: deprecate AVFormatParameters.standard.
...
Conflicts:
doc/APIchanges
doc/encoders.texi
ffmpeg.c
libavdevice/alsa-audio.h
libavformat/version.h
libavutil/opt.c
libswscale/rgb2rgb.h
libswscale/rgb2rgb_template.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
