[FFmpeg-devel] [PATCH] QCELP postfilter

Vitor Sessak vitor1001
Tue Mar 30 19:32:30 CEST 2010


Michael Niedermayer wrote:
> On Tue, Mar 30, 2010 at 06:42:27PM +0200, Vitor Sessak wrote:
>> Ronald S. Bultje wrote:
>>> Hi,
>>> On Mon, Mar 29, 2010 at 6:34 PM, Ronald S. Bultje <rsbultje at gmail.com> 
>>> wrote:
>>>> I guess my patch does something wrong. ;-). I'll see if I can get ref
>>>> minus postfilter as a comparison.
>>> Correction. The ref decoder always turned off the postfilter, because
>>> the patch from that mailinglist thread you pointed out never turned it
>>> on. ;-). No wonder it got worse.
>>> New results: http://people.gnome.org/~rbultje/cmp2.png
>>> Note how the last arrow ref decoder+postfilter is being clipped,
>>> whereas our results (plus postfilter) are unclipped (and thus better).
>>> bash-3.2$ tests/tiny_psnr ~/Desktop/out-{us,ref-pf}.wav 2 0 44
>>> stddev:  319.49 PSNR: 46.24 bytes:  8820800/  8820800
>> [...]
>>
>>> bash-3.2$ tests/tiny_psnr ~/Desktop/out-{nopf,ref-nopf}.wav 2 0 44
>>> stddev:  281.97 PSNR: 47.33 bytes:  8820800/  8820800
>> So adding postfiltering to both increase stddev of about 20%. A little big 
>> but acceptable IMHO.
> 
> you should be testing raw encoder input against decoder output for both
> the reference decoder and ours.

I'm not really sure that applies to a postfilter patch. Its main goal is 
not to improve PSNR...

-Vitor




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