[FFmpeg-devel] [PATCH] avformat/oggparseopus: fix segmented timestamps

Michael Niedermayer michaelni at gmx.at
Sat Jan 4 21:57:28 CET 2014


On Sat, Jan 04, 2014 at 12:19:41PM -0800, Mark Harris wrote:
> On Sat, Jan 4, 2014 at 11:59 AM, Michael Niedermayer <michaelni at gmx.at>wrote:
> 
> > On Tue, Dec 31, 2013 at 11:04:54AM -0800, Mark Harris wrote:
> > > Fix timestamp calculation for code 3 Ogg Opus packets with less than
> > > 2 bytes in the last segment (e.g. packet length 255 or 256).
> > > A sample that would seek incorrectly in ffplay can be created with:
> > >   ffmpeg -i in.wav -b:a 34k -vbr off -frame_duration 60 out.opus
> >
> > i dont seem to be able to reproduce the issue even though it seems
> > i did have a in.wav file in my local directory. Or maybe iam trying
> > the wrong things with the generated file
> >
> >
> The input audio doesn't matter as long as you can distinguish beginning,
> middle, and end (so don't use "sine" or a similar source).  It's the

ive used a 3 minute long piece of music (48khz stereo), seeking to the
middle works fine before this patch in ffplay.
That said i see that the code was wrong before. iam just trying to
understand how to reproduce this issue


> particular Opus packet sizes that cause the problem; encoding anything
> to 34kb/s CBR with 60ms frame duration will trigger the issue.
> Without the patch, "ffplay out.opus" and clicking in the middle of the
> window to seek to the middle will seek to the end instead, due to
> incorrect timestamps.



> 
>  - Mark
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-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Let us carefully observe those good qualities wherein our enemies excel us
and endeavor to excel them, by avoiding what is faulty, and imitating what
is excellent in them. -- Plutarch
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