[x264-devel] x264 SSIM analysis

[Niccolò Belli]

In data lunedì 24 febbraio 2014 22:12:47, BugMaster ha scritto:
> Because nowhere and never there was any official statemantes that same
> CRF will produce same PSNR/SSIM or same subjective quality with
> different settings (presets). If you thought so than you was wrong or
> was misleaded. All what CRF mode mean is constant ratefactor (notice
> it is ratefactor and not quality which are not equal thing). And
> constant ratefactor means more or less constant tradeoff bitween
> quality/bitrate along the the source (not between different sources or
> different options).

It makes sense. placebo will of course analize the frame better than veryfast 
and thus choose a more adeguate quantizer.
I'm pretty sure I read somewhere on the net that CRF aims to produce the same 
PSNR/SSIM but I'm not surprised to find out that someone misunderstood it.

Thanks,
Niccolò
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