[FFmpeg-devel] [RFC] AAC Encoder, now more optimal
Sun Sep 7 08:03:18 CEST 2008
On Sun, Sep 07, 2008 at 01:11:18AM +0200, Michael Niedermayer wrote:
> On Sat, Sep 06, 2008 at 08:15:55PM +0300, Kostya wrote:
> > On Sat, Sep 06, 2008 at 06:17:38PM +0200, Michael Niedermayer wrote:
> > > On Sat, Sep 06, 2008 at 06:36:16PM +0300, Kostya wrote:
> > [choosing codebooks for coeffients encoding]
> > > > IMO it should encode losslessly at this stage, so no rate distortion.
> > >
> > > How much quality do we loose from this?
> > none (yet) -
> You apparently misunderstood me, i meant
> how much quality is lost by ignoring distortion when choosing
> codebooks? Though this doesnt matter if you fix it and make it use full RD
> i just thought you wont from your first coment above. But judging from
> your next comment below it seem you do plan to fix this so its all fine
> and iam somewhat confused now :)
just wait and see ;)
> > quantization is performed the same way for all codebooks
> > I still have to introduce codebook-specific quantization (and distortion from it).
> It would be great if you did this before wasting more time with
> approximating it, because the exact solution may very well be faster than
> your approximation. pow() and cbrt() are rather slow and there is no need
> to search through the codebook bruteforce, but id like you to implement the
> bruteforce variant so we can verify that the optimized code does work
it was some thought barrier to me, will be implemented.
> Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
> Asymptotically faster algorithms should always be preferred if you have
> asymptotical amounts of data
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