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

[Baptiste Coudurier]

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.

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