[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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