[x264-devel] Re: non monotone timestamps...

[bond]

> Hi
>
> bond wrote:
> >> On Sun, Aug 20, 2006 at 02:04:22PM -0700, Loren Merritt wrote:
> >>> On Sun, 20 Aug 2006, Daniel J Blueman wrote:
> >>>
> >>>> When performing 2-pass encoding [1], I see many "non monotone
> >>>> timestamps" errors [2], so frames are dropped, resulting in a shorter
> >>>> video stream than the audio stream.
> >>>>
> >>>> I tracked this down to when the +bpyramid option is passed to x264;
no
> >>>> problem occurs with '-bpyramid', ie when using B-frames as references
> >>>> is disabled. I'm converting a MJPEG 640x480 30 fps video from my
> >>>> digital camera with ffmpeg etc trees from late Jul 06 subversion.
> >>>>
> >>>> Doing a quick search, it seems little is known about this issue. Any
> >>>> ideas? I'm not on the mailing list, so please CC.
> >>> libavformat doesn't support bpyramid.
> >> do you know why? no i am not aware of an issue with bpyramid and lavf
> >> just mencoder + bframes
> >
> > the ctts atom isnt created correctly when using b-pyramid with x264
> > outputting to .mp4, therefore ffmpeg is not able to create spec
compliant
> > mp4 files when using b-pyramid (normal b-frames are fine)
> >
> > x264's own tool handles this fine
> >
>
> 'ctts' atom is actually created correctly. If a problem resides, it is
> most likely cause pts and/or dts of the packets are incorrect.
>
> Problem with B pyramid is just that lavf will not let packets pass since
> they have non monotone timestamps as mentioned in the first post of the
> thread.

the ctts atom is NOT created correctly with b-pyramid in ffmpeg!

i have just tested it again with revision 6129. i compared the ctts to what
mp4box and mp4creator create for the stream and let mp4box analyse the ctts
atom resulting into the logfile attached showing the errors

my commandline used:
ffmpeg -s 352x144 -i "c:\...\matrix.yuv" -y -vcodec h264 -bf 3 -bpyramid 1
ffmpeg.mp4
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