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.
Many of these functions were named foo_free_context, and since
the functions no longer should free the context itself, only
allocated elements within it, the previous naming was slightly
misleading.
Signed-off-by: Martin Storsjö <martin@martin.st>
This makes it more consistent with depacketizers that don't have any
.free function at all, where the payload context is freed by the
surrounding framework. Always free the context in the surrounding
framework, having the individual depacketizers only free any data
they've specifically allocated themselves.
This is similar to how this works for demuxer/muxers/codecs - a
component shouldn't free the priv_data that the framework has
allocated for it.
Signed-off-by: Martin Storsjö <martin@martin.st>
This avoids exposing a dummy AVStream which won't get any data
and which will make avformat_find_stream_info wait for info about
this stream.
Signed-off-by: Martin Storsjö <martin@martin.st>
In the name of consistency:
put_byte -> avio_w8
put_<type> -> avio_w<type>
put_buffer -> avio_write
put_nbyte will be made private
put_tag will be merged with avio_put_str
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
The vorbis decoder doesn't handle more than one audio frame packed into
the same AVPacket, so they need to be split in the depacketizer.
Originally committed as revision 24704 to svn://svn.ffmpeg.org/ffmpeg/trunk
This can avoid segfaults in some cases.
Patch by Josh Allmann, joshua dot allmann at gmail
Originally committed as revision 24537 to svn://svn.ffmpeg.org/ffmpeg/trunk
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
codec, so there's no reason to (invalidly) limit it to only Theora.
Also fixes issue 1880 (compilation error on -DDEBUG).
Originally committed as revision 22886 to svn://svn.ffmpeg.org/ffmpeg/trunk
AVERROR(ENOMEM).
AVERROR_NOMEM is deprecated and will be dropped at the next libavutil
major bump.
Originally committed as revision 22791 to svn://svn.ffmpeg.org/ffmpeg/trunk
This was accidentally overwritten in the recent merge of the theora/vorbis codepaths
Originally committed as revision 22774 to svn://svn.ffmpeg.org/ffmpeg/trunk
the Vorbis / theora depacketizers.
Patch by Josh Allmann <joshua DOT allmann AT gmail DOT com>.
Originally committed as revision 22765 to svn://svn.ffmpeg.org/ffmpeg/trunk
