[Ffmpeg-cvslog] r8182 - trunk/doc/TODO

[Michael Niedermayer]

Hi

On Fri, Mar 02, 2007 at 10:54:19AM +0100, Baptiste Coudurier wrote:
> Hi
> 
> Nico Sabbi wrote:
> > bcoudurier wrote:
> > 
> >> - mpeg2 non linear quantizer
> >>  
> >>
> > is this implemented? how to use it? what are the benefits?
> > 
> 
> Nope, It's on my TODO, after digging a bit, it seems it would be needed
> to use a completely different quantization code, since other codecs
> using mpegvideo.c are using linear one, maybe Im wrong though, some mpeg
> code is still black magic for me.
> 
> static const uint8_t non_linear_qscale[32] = {
>     0, 1, 2, 3, 4, 5, 6, 7,
>     8,10,12,14,16,18,20,22,
>     24,28,32,36,40,44,48,52,
>     56,64,72,80,88,96,104,112,
> };
> 
> Benefits is capability to use 1,3,5,7... quantization coefficients, and
> then going up to 112, which in practice improve very high bitrates
> quality and also should compress more at (very)low bitrates.

video above mpeg2 qscale 62 looks too bad to be useable, and below 
mpeg2 qscale 2 you will not see a difference, the only usefull thing
in this is maybe 3 and 5

so IMO the whole thing is a waste of time

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I count him braver who overcomes his desires than him who conquers his
enemies for the hardest victory is over self. -- Aristotle
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