It is only used by demuxers (although it is hypothetically
possible that some day e.g. a protocol might need it, but
that is unlikely given that they don't deal with AVCodecParameters).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
These functions already free it themselves before they allocate the new
extradata.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Some muxers may use the BMP_HEADER Format Data size instead
of the ASF-specific one.
Bug-Id: 1020
CC: libav-stable@libav.org
Signed-off-by: Diego Biurrun <diego@biurrun.de>
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.
Due to this bug in VC++ 2015 Update 1:
https://connect.microsoft.com/VisualStudio/feedback/details/2291638
the 'key' array in ff_read_riff_info() ends up being not null
terminated which led to failures in a Chromium unit tests. Update 2
should have a fix, but until then it is important to avoid problems.
This avoids a division by zero for G726.
Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>
Andreas Rheinhardt
Vittorio Giovara
Paul B Mahol
Andreas Rheinhardt
Thierry Foucu
Alexandra Hájková
Hendrik Leppkes
Carl Eugen Hoyos
Anton Khirnov
Bruce Dawson
Michael Niedermayer
Andreas Cadhalpun
Luca Barbato
Michael Niedermayer
Thomas Volkert
James Almer
Martin Storsjö
Diego Biurrun