[MPlayer-dev-eng] [PATCH] Adaptive quantization

[Guillaume POIRIER]

Hi,

On 6/4/05, The Wanderer <inverseparadox at comcast.net> wrote:
> Guillaume POIRIER wrote:
> 
> > Hi there,
> > The attached patch adds adaptive quantization to MEncoder for XviD.
> >
> > Please comment, review (especially the doc part).
> 
> Since that's all I'm qualified to review anyway:

:-)


> > +.B (no)adaptive_quant
> > +Adaptive quantization allows each quant to differ inside each frame.
> 
> The phrasing "each quant" seems to imply that there are multiple
> different quantizers, which if true would be news to me. If it isn't
> true, then "the quantizer" would be better.

I'm not 100% sure, but there are 2 types of quants: global picture
quant and macroblock quant. Here's a better description of this
options that features your remarks:

.B (no)adaptive_quant
Adaptive quantization allows each macroblock quant to vary inside
each frame.
This is a 'psychosensory' setting that is supposed to make use of the
fact that the human eye tends to notice fewer details in very bright
and very dark parts of the picture.
It compresses those areas more strongly than medium ones, which will
save bits that can be spent again on other frames, raising overall
subjective quality and possibly reducing PSNR.


Guillaume
-- 
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