Converting explicit avio_flush() calls helps us to buffer more data and avoid
flushing the IO context too often which causes reduced IO throughput for
non-streamed file output.
The user can control FLUSH_POINT flushing behaviour using the -flush_packets
option, the default typically means to flush unless a non-streamed file output
is used, so this change should have no adverse effect on streaming even if it
is assumed that after an avio_flush() the output buffer is clean so small
seekbacks within the output buffer will work even when the IO context is not
seekable.
Signed-off-by: Marton Balint <cus@passwd.hu>
If there is an error in mpeg_mux_init() (the write_header function of
the various MPEG-PS muxers), two things might happen:
1. Several fifos might leak. Instead of freeing them, the goto fail part
of the functions freed the private data of the AVStreams instead,
although this will be freed later in free_stream() anyway.
2. And if the function is exited via goto fail, it automatically
returned AVERROR(ENOMEM), although this is also used when the error is
not a memory allocation failure.
Both of these issues happened in ticket #8284 and have been fixed.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
The MPEG-PS muxer only accepts PCM streams having up to 8 channels
and the following sampling rates: 32/44.1/48/96 kHz.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
PCM_S16BE stream packets in MPEG-PS have a 3-byte header and
are recognized as PCM_DVD by the demuxer which prevents their
correct remuxing in MPEG-1/2 PS.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
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.
Marton Balint
James Almer
Andreas Rheinhardt
Gyan Doshi
Paul B Mahol
Michael Niedermayer
Vittorio Giovara
Anton Khirnov
Stefano Sabatini
Michael Niedermayer
Diego Biurrun
Luca Barbato
Lukasz Marek
Carl Eugen Hoyos
Martin Storsjö