[FFmpeg-devel] [RFC] AAC Encoder

Loren Merritt lorenm
Mon Aug 18 03:17:09 CEST 2008

On Sun, 17 Aug 2008, Michael Niedermayer wrote:

> the scalefactors from the psy model should be useable as RD factors for
> weighting between rate and distortion. Iam pretty sure a relation like
> lambda = A*sf^B  with A and B constants should be more than good enough
> for our purposes, it is for mpeg4 ASP. I guess loren or dark shikari can
> comment on what the relation commonly used in h.264 between the quantization
> factor (NOT QP which has a log scale) and lambda is?

lambda for SAD is directly proportional to quantizer. lambda for SSD is 
proportional to quantizer^2.

--Loren Merritt

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