[FFmpeg-devel] About guess_correct_pts / AVFrame.best_effort_timestamp

Ronald S. Bultje rsbultje
Wed Feb 16 17:02:46 CET 2011


On Wed, Feb 16, 2011 at 7:26 AM, Nicolas George
<nicolas.george at normalesup.org> wrote:
> Commit 76ad67c introduced best_effort_timestamp into AVFrame and moved
> guess_correct_pts from cmdutils to lavc. It was accepted in ffmpeg at videolan
> but not in ffmpeg at ffmpeg.

I have no idea what guess_correct_pts or best_effort_timestamp is.
I've brought up in one of these troll-threads that I want the whole
PTS/DTS thing explained to me before any more change goes in. You went
as far as to admit that "if A and B and C and D and E and F, then
maybe sometimes perhaps PTS is this and otherwise it's very complex".
Reimar simply admitted it's incomprehensible.

I want this whole mess re-designed. best_effort_timestamp may or may
not be part of the solution.

First of all, where. This should be in lavf, not lavc, otherwise
transcoding of formats where timestamps are missing to those where
they are required doesn't work. lavc should do nothing more but
reorder timestamps for these formats where display order != coding

If you accept that premise, I'm willing to help looking into a
solution that removes any and all non-reordering code from lavcodec,
obliviates any and all timestamp screwups in ffmpeg.c, cmdutils.c,
ffplay.c etc, and cleanly implements format-specific hacks where they
belong: in lavformat.


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