[FFmpeg-devel] [RFC] AAC Encoder

Michael Niedermayer michaelni
Mon Aug 18 03:47:37 CEST 2008

On Sun, Aug 17, 2008 at 07:17:09PM -0600, Loren Merritt wrote:
> 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.

thanks, its the same in mpeg4 ASP / h263

So i would suspect this will also hold true for AAC ...

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

When the tyrant has disposed of foreign enemies by conquest or treaty, and
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