[FFmpeg-devel] [RFC] Videos that change colorspace

Jason Garrett-Glaser darkshikari
Thu Jun 18 18:06:18 CEST 2009


On Thu, Jun 18, 2009 at 2:46 AM, Michael Niedermayer<michaelni at gmx.at> wrote:
> On Wed, Jun 17, 2009 at 06:53:39PM -0700, Jason Garrett-Glaser wrote:
>> Some quite popular camera is producing MJPEG videos that change
>> colorspace: the first frame is YUVJ422P and all frames afterwards are
>> YUVJ420P.
>>
>> This crashes ffmpeg (since swscale doesn't get re-initted after the
>> video finding a new colorspace, and attempts to resample chroma that
>> doesn't exist). ?It creates rather funky video in Virtualdub as well,
>> but works perfectly in FFDshow+MPC on Windows.
>>
>> The relevant ticket can be found here:
>> https://roundup.ffmpeg.org/roundup/ffmpeg/issue1165
>>
>> To give you an idea of how widespread this issue is, Facebook receives
>> (my estimate based on grepping the logs) around one thousand of these
>> files a day.
>>
>> How should we deal with this issue?
>
> same as with resolution changes ... theres a patch for the later that i
> should review ...
>
> anyway, any idea why th cammera does that?

By the way, my local hacky solution is to track pix_fmt and re-init
swscale if pix_fmt changes.

Dark Shikari



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