[Ffmpeg-devel] PTS / DTS with XViD

Måns Rullgård mru
Sat Jul 22 11:28:19 CEST 2006

Rich Felker said:
> On Fri, Jul 21, 2006 at 08:01:13PM +0300, Jani Boutellier wrote:
>> As a concluding remark, I'll have to state that the problem was not at all
>> in the OGM format.
>> After hours of trial and error I managed to get the XViD-encoded video into
>> a MPEG4 -container (.mp4). Surprisingly the the abovementioned problem with
>> OGM occurred also with mp4, so I figured that the true source of problems
>> was XViD.
>> Soon I discovered that the video clips I had used, contained a so-called
>> "packed bitstream", which meant that the B-frames were crammed inside
>> P-frames. After I changed this in encoding settings and re-encoded the
>> video clips, the decoding worked well.
> Did ffmpeg generate these bitstreams? I sure hope it's not calling
> xvid with packed bitstream enabled...

FFmeg doesn't mux OGM so it can't have made those files.

>> This means that although the OGM format was labeled as a "broken format" in
>> this thread, it probably would work well also with b-frames. However, I
>> didn't try that in practice anymore, since I'm happy with mp4 now :)
> I imagine the timestamps would still be invalid but I'm not sure..

Ogg only has frame count, no real timestamps.

M?ns Rullg?rd
mru at inprovide.com

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