[FFmpeg-soc] [PATCH] AMR-WB Decoder
Marcelo Galvão Póvoa
marspeoplester at gmail.com
Sun Sep 5 00:23:02 CEST 2010
On 4 September 2010 15:16, Vitor Sessak <vitor1001 at gmail.com> wrote:
> On 09/04/2010 05:22 PM, Marcelo Galvão Póvoa wrote:
>> On 4 September 2010 06:02, Vitor Sessak<vitor1001 at gmail.com> wrote:
>>> On 09/03/2010 11:50 PM, Marcelo Galvão Póvoa wrote:
>>>> Also, whether with this patch or not I guess my output to the first
>>>> sample above (attached) is not good compared to the reference decoder.
>>>> The are some sharp peaks that can be seen with Audacity, one of them
>>>> also with clipping. The stddev I've got seems ugly:
>>>> stddev: 884.86 PSNR: 37.39 MAXDIFF:23298 bytes: 473600/ 473600
>>> Indeed, the stddev is not particularly good, but don't trust only it to
>>> comparisons. A very small phase shift can completely ruin the stddev.
>>> Do you see sharp peaks in your output that are not there in the reference
>>> decoder? Or the sharp peaks shows up when you invert and superpose the
>>> waves? Do these sharp peaks gives audible artifacts?
>> Sorry, I've forgot to mention that I was comparing the reference
>> decoder output waveform with mine. In general, they look mostly the
>> same but there are some 3 or 4 points in which my decoder gives a
>> short peak. I couldn't notice audible artifacts at these moments.
> It does looks like a bug :(
I've just tested dumping all the voice_factor() values from the
reference decoder (I suspected this function was problematic) and the
output difference was not too much:
all_man.awb stddev: 0.38 PSNR:104.69 MAXDIFF: 4 bytes: 473600/ 473600
The sharp peaks and the clipping are still there, so I guess we can
discard checking this function.
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