The current muxer behaviour is to create streams in read_header() based
on the audio/video presence flags, but fill in the stream parameters
later when we actually get some packets for them. This is rather shady,
since other demuxers set the stream parameters immediately when the
stream is created and do not touch the stream codec context after that.
Change the flv demuxer to behave in the same way as other similar
demuxers -- create the streams only when we get a packet for them.
Almost all the places from which this function is called already check
the header manually and in the two that don't (the mp3 muxer) the check
should not cause any problems.
It will not be set unless the muxing codec context is also the encoding
context, which is discouraged. When the frame size is not known from
av_get_audio_frame_duration(), the fallback should still be good enough.
It will not be set if the stream codec context is not the encoding
context. Use av_get_audio_frame_duration() instead, it should work for
all audio codecs supported by the muxer.
matroskaenc applies divisors to the display width/height when generating
stereo content. This patch adds the corresponding multipliers to matroskadec
so that the original sample aspect ratio can be recovered.
Signed-off-by: wm4 <nfxjfg@googlemail.com>
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
These variables are coming from mpegvideoenc where are supposedly used
as bit counters on various frame properties. However their use is
unclear as they lack documentation, are available only from a very small
subset of encoders, and they are hardly used in the wild. Also frame_bits
in aacenc is employed in a similar way.
Remove this functionality from AVCodecContex, these variable are mostly
frame properties, and too few encoders support setting them with anything
useful.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Most option values are simply unused or ignored and in practice the
majory of codecs only need to check whether to enable rle or not.
Add appropriate codec private options which better expose the allowed
features.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Checking the codec context parameters to find out this information is
far too unreliable to be useful, so it is safer to assume B-frames are
always present.
Fall back to maximum DPB size if the level is unknown.
This should be more spec-compliant and does not depend on the caller
setting has_b_frames before opening the decoder.
The old behaviour, when the delay is supplied by the caller setting
has_b_frames, can still be obtained by setting strict_std_compliance
below normal.
According to the spec, the reference list for a slice should be
constructed by first generating an initial (what we now call "default")
reference list and then optionally applying modifications to it.
Our code has an optimization where the initial reference list is
constructed for the first inter slice and then rebuilt for other slices
if needed. This, however, adds complexity to the code, requires an extra
2.5kB array in the codec context and there is no reason to think that it
has any positive effect on performance. Therefore, simplify the code by
generating the reference list from scratch for each slice.
Anton Khirnov
Dave Yeo
Luca Barbato
Aaron Colwell
Vittorio Giovara
Ganesh Ajjanagadde