[FFmpeg-soc] [PATCH] AMR-WB Decoder

[Marcelo Galvão Póvoa]

Hello,

On 6 September 2010 10:13, Ronald S. Bultje <rsbultje at gmail.com> wrote:
> Hi,
>
> On Mon, Sep 6, 2010 at 5:54 AM, Vitor Sessak <vitor1001 at gmail.com> wrote:
>> On 09/06/2010 02:46 AM, Marcelo Galvão Póvoa wrote:
>>> Ok, fortunately I've found the bug!
>>>
>>> It was just a MIN_ISF_SPACING parameter which I extracted from the
>>> reference code but was unsure about it's Q level. After some time, I
>>> thought I have it figured out but I was wrong. Now I know the answer
>>> the hard way...
>>>
>>> The clipping and the sharp peaks are gone, the waveforms are really
>>> close now!
>>
>> That's great news!
>>
>>> Also, the stddev against the reference decoder decreased a
>>> lot (it was ~884 before):
>>> all_men.awb stddev:   51.72 PSNR: 62.05 MAXDIFF: 1089 bytes:   473600/
>>> 473600
>>
>> stddev of 51 looks pretty good to me for this case.
>
> Maxdiff of 1089 looks like a lot to me, with a low stddev that
> suggests that one particular part is off. Can you trace which part is
> off and why (phase shift vs. actual bug)?
>

Sorry, but can you suggest a way of doing it? Also, what do MAXDIFF
and the "2" at the end of the command line mean?

This sample have long silence parts and I'm comparing my floating
point implementation to the reference 16-bit fixed point. How close
you think they should be? I did the same test with the AMR-NB decoder
from ffmpeg and the result was the following:

stddev:   46.36 PSNR: 63.00 MAXDIFF:  452 bytes:   236800/   236800

-- 
Marcelo