The child_class_next API relied on different (de)muxers to use
different AVClasses; yet this API has been replaced by
child_class_iterate.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This is possible now that the next-API is gone.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Signed-off-by: James Almer <jamrial@gmail.com>
The MPEG-PS muxer uses a custom queue of custom packets. To keep track
of it, it has a pointer (named predecode_packet) to the head of the
queue and a pointer to where the next packet is to be added (it points
to the next-pointer of the last element of the queue); furthermore,
there is also a pointer that points into the queue (called premux_packet).
The exact behaviour was as follows: If premux_packet was NULL when a
packet is received, it is taken to mean that the old queue is empty and
a new queue is started. premux_packet will point to the head of said
queue and the next_packet-pointer points to its next pointer. If
predecode_packet is NULL, it will also made to point to the newly
allocated element.
But if premux_packet is NULL and predecode_packet is not, then there
will be two queues with head elements premux_packet and
predecode_packet. Yet only elements reachable from predecode_packet are
ever freed, so the premux_packet queue leaks.
Worse yet, when the predecode_packet queue will be eventually exhausted,
predecode_packet will be made to point into the other queue and when
predecode_packet will be freed, the next pointer of the preceding
element of the queue will still point to the element just freed. This
element might very well be still reachable from premux_packet which
leads to use-after-frees lateron. This happened in the tickets mentioned
below.
Fix this by never creating two queues in the first place by checking for
predecode_packet to know whether the queue is empty. If premux_packet is
NULL, then it is set to the newly allocated element of the queue.
Fixes tickets #6887, #8188 and #8266.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Fixes: signed integer overflow: -9223372036854775808 - 45000 cannot be represented in type 'long'
Fixes: ticket8187
Found-by: Suhwan
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
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.
Andreas Rheinhardt
Andreas Rheinhardt
Michael Niedermayer
Marton Balint
James Almer
Gyan Doshi
Paul B Mahol
Vittorio Giovara
Anton Khirnov
Stefano Sabatini
Michael Niedermayer
Diego Biurrun
Luca Barbato
Lukasz Marek
Carl Eugen Hoyos