[FFmpeg-devel] [PATCH v3 3/6] ffmpeg: move A/V non-streamcopy initialization to a later point

Jan Ekström jeebjp at gmail.com
Mon Oct 19 23:29:30 EEST 2020

On Sat, Oct 17, 2020 at 3:32 AM Jan Ekström <jeebjp at gmail.com> wrote:
> On Fri, Oct 16, 2020, 22:47 Michael Niedermayer <michael at niedermayer.cc> wrote:
>> On Fri, Oct 16, 2020 at 04:16:46PM +0300, Jan Ekström wrote:
>> > - For video, this means a single initialization point in do_video_out.
>> > - For audio we unfortunately need to do it in two places just
>> >   before the buffer sink is utilized (if av_buffersink_get_samples
>> >   would still work according to its specification after a call to
>> >   avfilter_graph_request_oldest was made, we could at least remove
>> >   the one in transcode_step).
>> >
>> > Other adjustments to make things work:
>> > - As the AVFrame PTS adjustment to encoder time base needs the encoder
>> >   to be initialized, so it is now moved to do_{video,audio}_out,
>> >   right after the encoder has been initialized. Due to this,
>> >   the additional parameter in do_video_out is removed as it is no
>> >   longer necessary.
>> > ---
>> >  fftools/ffmpeg.c | 112 ++++++++++++++++++++++++++++++++---------------
>> >  1 file changed, 77 insertions(+), 35 deletions(-)
>> This breaks:
>> ./ffmpeg -ss 30.0 -i ~/tickets/1745/1745-Sample.mkv -f vob -c:a copy  -f framecrc -
> I put the first attempt at a fix for this as a separate commit in this patch set since it clearly is separate from this change by itself, as well as if someone would give a better recommendation on how to handle it, it would be simpler to adjust.

In case it was not obvious from this reply, my initial attempt to
improve this handling would be

As noted, I decided that this would be another change in the behavior
and this at least until there's been some review/discussion about it,
it should be a separate change from this one. That is why this test
case fails with just this patch of this patch set applied. I did not
specifically ignore it because you were nice enough to point at it


More information about the ffmpeg-devel mailing list