[FFmpeg-devel] New to the list

Stefan Gehrer stefan.gehrer
Tue Sep 23 08:47:27 CEST 2008


Jason Garrett-Glaser wrote:
> On Mon, Sep 22, 2008 at 1:36 PM, Stefan Gehrer <stefan.gehrer at gmx.de> wrote:
>> Jason Garrett-Glaser wrote:
>>> 5.  Port any number of algorithmic encoding improvements pioneered by
>>> x264 into libavcodec to improve the encoding of older formats.
>> This made me curious, could you elaborate or point to a source
>> what these improvements are? I saw you blogging about Psy-RDO,
>> any other big topics?
> 
> 1.  A useful adaptive quantization method (the current ones in lavc
> are, last I checked, not just bad but actually broken to some extent).
>  This should be trivial to port; I literally ported it to Xvid in less
> than 20 minutes without any prior knowledge of the Xvid code.  Its
> design wasn't ideal, but at least it worked.

By adaptive quantization do you mean varying the qp value on a
macroblock basis? If so, is the quantizer of the macroblock dependent
on its content or found before encoding the macroblock by some
ratecontrol mechanism?




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