[FFmpeg-devel] [PATCH 2/2] Add SIPR decoder for 5k0, 6k5 and 8k5 modes

Vitor Sessak vitor1001
Thu Jan 14 05:07:40 CET 2010


M?ns Rullg?rd wrote:
> "Ronald S. Bultje" <rsbultje at gmail.com> writes:
> 
>> Hi,
>>
>> On Sun, Jan 10, 2010 at 4:43 PM, Vitor Sessak <vitor1001 at gmail.com> wrote:
>>> Now the patch that adds 16k support. I'm undecided if I should put this code
>>> in a separated file...
>> Index: libavcodec/siprdata.h
>> [..]
>> +static const float gain_cb_16k[32] =
>> +{
>> +    0.07499,     0.10593,     0.14125,     0.18836,
>>
>> Lots of spaces?
>>
>> [..]
>>
>> Index: libavcodec/sipr.c
>> [..]
>> +    int ma_pred_switch;        ///< switched MA predictor
>>
>> What's MA?
> 
> Moving average?
> 
>> +/**
>> + * Convert an lsf vector into an lsp vector.
>> + *
>> + * @param lsf               input lsf vector
>> + * @param lsp               output lsp vector
>> + */
>> +static void lsf2lsp(float *lsf, double *lsp)
>> +{
>> +    int i;
>>
>> -static void dequant(float *out, const int *idx, const float *cbs[])
>> +    for (i = 0; i < LP_FILTER_ORDER_16k; i++)
>> +        lsp[i] = cos(lsf[i]);
>> +}
>> +
>> +static void dequant(float *out, const int *idx, const float *cbs[],
>> +                    int mode_16k)
>>
>> I wish we could teach diff how silly this looks. Just look.
>>
>> You can mark lsf as const, maybe makes it a bit faster, since it's not
>> changed in the function. the same could probably be done elsewhere
>> also (not critical...).
> 
> It is generally a good idea to use const where possible.  There's a
> slight chance of getting better code, and it avoids accidentally
> modifying something.
> 




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