[Ffmpeg-devel] improving encoding (possibly big perceptual gains)

Michael Niedermayer michaelni
Mon Jan 2 20:35:40 CET 2006


On Mon, Jan 02, 2006 at 01:56:59PM -0500, Rich Felker wrote:
> > that ignore flickering/blinking but if done per block brightness will
> > be off per block this will not look good at all -> PSNR is still the
> > better cmp function for these decissions, maybe it should be done in
> > dct domain and different frequencies should be weighted differently
> > maybe a closer to 0 error should be considered less wrong then a farther
> > away from zero error ...
> IMO this does not address the problem I'm talking about. A motion
> block with correlaton perfect but brightness way off is still very
> good since a single DC coefficient can encode the residue perfectly
> and no detail will be lost. PSNR-based motion estimation will often
> choose a solid or near-solid block when there's very little detail,
> resulting in the same kinda ugliness that we've been seeing. (The
> coefficients of the residue are very small and high-frequency so they
> get quantized to 0..)

SATD and DCT based cmp functions are available and probably outperform
Correlation+Brightness but feel free to implement a better one, just
look at the cvslog entries of a case where a new cmp function was added



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