[theora] ffmpeg2theora 0.25 synchronization issues when converting from .mov

Andrew Chew andrew at okashistudios.com
Sun Oct 4 20:06:37 PDT 2009

On Oct 4, 2009, at 7:16 PM, Michael A. Peters wrote:

> Andrew Chew wrote:
>>> I just realized that I normally convert my videos using the Xiph   
>>> Quicktime components.  I stopped using that when I upgraded to  
>>> Snow  Leopard and realized that the Xiph Quicktime components  
>>> don't work  with the latest Quicktime that ships with Snow  
>>> Leopard.  In any  case, I've never had problems converting using  
>>> that.  It's only when  I went to using ffmpeg2theora that I  
>>> started having these problems.
>>> So it would appear that there's more evidence that this is an  
>>> ffmpeg  problem, not a theora problem.
>> Oops.  Didn't send to the whole mailing list.  Resending.
> Something you might want to try rather than downgrading you  
> QuickTime is transcoding to mpeg2 first.
> That's how I solved a different ffmpeg2theora problem.
> Going from dv source (adjust args accordingly):
> ffmpeg -i $video.dv -deinterlace -vcodec mpeg2video \
>   -qscale 1 -qmin 1 -intra -an -y video.m2v
> ffmpeg -i video.dv -acodec copy -vn -y video.wav
> That demuxes the source into m2v video and wav audio
> Then -
> ffmpeg2theora-0.25 video.m2v --noaudio --two-pass -V ${vid} \
>  -x ${wid} -y ${hei} -o video_tmp.ogv
> oggenc -b ${aud} video.wav -o video_tmp.ogg
> That endodes the video as theora and audio as ogg.
> ${vid} is target bitrate, etc.
> oggzmerge -o video.ogv video_tmp.ogv video_tmp.ogg
> That muxes the theora video and ogg audio into single file.
> oggzmerge is not standard part of ogg tools, I think it is in  
> package called oggz-tools.

Thanks :)  I'll try that some time.  But I've already grabbed the old  
Quicktime 7 with the latest Xiph component for ogv (that has libtheora  
1.1), and did a conversion.  Synchronization is perfect with this.

So I think the problem is very likely to be an ffmpeg issue, and not a  
theora issue.

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