[FFmpeg-devel] [PATCH] QCELP decoder

[Kenan Gillet]

On Oct 17, 2008, at 4:30 PM, Michael Niedermayer wrote:
>>>> +
>>>> +    for (i = 0; i < 160; i++)
>>>> +        outbuffer[i] = av_clipf(outbuffer[i], -8192., 8191.75) /
>>>> 8192.;
>>>
>>> cant this scale factor be merged into some tables?
>>
>> by merging it in qcelp_g12ga and testing on the samples
>> from samples.mplayerhq.hu and others:
>>
>> I use 'ffmpeg --i sample_file sample_file.wav' to create the output
>> I use md5sum to check if the output had changed
>>  and run 'tiny_psnr old_file new_file' if it had.
>>
>> here are the results:
> [...]
>> qtaudio-qcelp-problem.3g2: audio mismatchs from previous build
>>     stddev:   11.93 PSNR: 26.59 bytes:   208044/   208044
>>
> [...]
>> zg3dx2d6.3g2: audio mismatchs from previous build
>>     stddev:   17.77 PSNR: 23.12 bytes:   486444/   486444
>>
>> vidoo_MP4_audio_Qcelp13k.k3g: audio mismatchs from previous build
>>     stddev:   10.94 PSNR: 27.34 bytes:   743724/   743724
>>
>>
>> does it look reasonable ? is at acceptable?
>
> i think not, question is, why do these differ?
> There really should be no difference just from scaling floats  
> differently

fixed, i forgot to update the clipping values :(