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.
Since 596e5d4783, this is not necessary anymore. It also allows to
actually disable the flushing, improving write performance (but
possibly giving worse latency in real-time streaming).
Signed-off-by: Martin Storsjö <martin@martin.st>
This isn't required any longer, when the mpegts muxer uses it
as a proper chained muxer.
Signed-off-by: Jindrich Makovicka <makovick@gmail.com>
Signed-off-by: Martin Storsjö <martin@martin.st>
Pass the correct size in bits to mpeg4audio_get_config and add a flag
to disable parsing of the sync extension when the size is not known.
Latm with AudioMuxVersion 0 does not specify the size of the audio
specific config. Data after the audio specific config can be
misinterpreted as sync extension resulting in random and wrong configs.
Parse the extension flag bit when reading the MPEG4 AudioSpecificConfig.
This has nothing to do with SBR/PS contradictory to what was noted when it was removed.
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 ADTS output files are not explicitly signaled because the format
does not support explicit signalling.
Originally committed as revision 23935 to svn://svn.ffmpeg.org/ffmpeg/trunk
function ‘ff_log_missing_feature’
Patch by Patrik Kullman ( patrik yes nu )
Originally committed as revision 17220 to svn://svn.ffmpeg.org/ffmpeg/trunk
members and erroring out if invalid
Patch by Alex Converse ( alex converse gmail com )
Originally committed as revision 17193 to svn://svn.ffmpeg.org/ffmpeg/trunk
patch by Stefano Sabatini, stefano.sabatini-lala poste.it
along with some spelling/consistency fixes for the long names by me
Originally committed as revision 13649 to svn://svn.ffmpeg.org/ffmpeg/trunk
patch by: Björn Axelsson, bjorn d axelsson a intinor d se
thread: [PATCH] Remove static ByteIOContexts, 06 nov 2007
Originally committed as revision 11071 to svn://svn.ffmpeg.org/ffmpeg/trunk
CONFIG_MUXERS from adtsenc.c, fixes compilation with --disable-muxers.
patch by Luca Abeni, lucabe72 &at& email &dot& it
Originally committed as revision 5030 to svn://svn.ffmpeg.org/ffmpeg/trunk
