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

[Loren Merritt]

On Sat, 4 Jun 2005, Guillaume POIRIER wrote:
> On 6/4/05, The Wanderer  wrote:
>> Guillaume POIRIER wrote:
>
>>> +.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.

"allows the macroblock quants to vary".
IMHO "each macroblock" is inappropriate because a single macroblock's 
quant is constant.

> 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.

"but possibly reducing PSNR".

--Loren Merritt