[FFmpeg-devel] RoQ colorspace inflated

Mike Melanson mike
Sat Jan 24 04:01:31 CET 2009

Vitor Sessak wrote:
> Mike Melanson wrote:
>> Hi,
>> I was looking at the RoQ video decoder. I noticed that the colorspace is 
>> set as YUV444P. Natively, RoQ video is YUV420P. I see that the decoder 
>> unpacks the YUV420 pixels and manually upscales the chroma samples. Is 
>> there a good reason for this?
> Yes, actually the decoder use YUV420 to store the codebooks but does 
> motion compensation using full YUV444 (or in the original decoder, RGB). 
>   Eric Lasota (who sent the patch for this change) sent a sample that 
> didn't decoded with artifacts in the YUV420 colorspace, but correctly in 
> Quake3. See 
> http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2007-June/030404.html 
> and for the sample http://icculus.org/~riot/redbox.bz2 .

Thanks. I was thinking about my question today and it occurred to me 
that this might be the explanation.

     -Mike Melanson

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