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Old 23rd November 2011, 16:42   #14  |  Link
poisondeathray
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Join Date: Sep 2007
Posts: 5,345
Quote:
Originally Posted by Yellow_ View Post
My comment was with regard to the assumption that people take 'lossless' as 'harmless' conversion, I was suggesting where that assumption could be incorrect and lead to unnecessary degrading of a perfectly decent source. :-)

Can you suggest a lossless codec that supports full range luma when transcoding from h264 4:2:0? utcodec, huffyuv and lagarith don't appear to with ffmpeg, from tests I've done, in the case of huffy & utcodec they go to YUY2 and squeeze luma.

I don't think it's misleading to express concern over so called lossless codecs.

Here's a simple example of a codec mishandling a full luma h264 AVC 4:2:0 source as per utcodec, lagarith, huffyUV and the resulting in the conversion to RGB, again with regard to NLE / media player use.

http://forum.doom9.org/showthread.ph...23#post1525723
Just to clarify, the "lossless" codecs are lossless in the same colorspace

It's not the codec author's fault if the other application treats it as RGB, incurring a Rec601/709 conversion

If you don't import into a regular NLE, and just use avisynth, you can keep the same colorspace.

Those lossless codecs (UT, huffyuv, lagarith etc... ) do accept full luma range - you're incurring a RGB conversion somewhere that is causing loss of superbrights/darks
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