[FFmpeg-soc] [soc]: r4376 - in amr: amrnbfloatdata.h amrnbfloatdec.c

[Colin McQuillan]

2009/6/2 Robert Swain <robert.swain at gmail.com>:
> cmcq wrote:
>>
>> Author: cmcq
>> Date: Tue Jun  2 13:58:23 2009
>> New Revision: 4376
>>
>> Log:
>> Rescale AMR samples from 16-bit PCM values
>> The samples /A-codecs/amr/{sample,sample2,whatireallywant}.amr now produce
>> recognizable output. There is still significant distortion.
>
> Great! :D
>
>> Modified:
>>   amr/amrnbfloatdata.h
>>   amr/amrnbfloatdec.c
>>
>> Modified: amr/amrnbfloatdata.h
>>
>> ==============================================================================
>> --- amr/amrnbfloatdata.h        Mon Jun  1 19:34:02 2009        (r4375)
>> +++ amr/amrnbfloatdata.h        Tue Jun  2 13:58:23 2009        (r4376)
>> @@ -38,6 +38,9 @@
>>  #define AMR_BLOCK_SIZE    160
>>  #define AMR_SUBFRAME_SIZE  40
>>  +// AMR is designed to produce 16-bit PCM samples (3GPP TS 26.090 4.2)
>> +#define AMR_SAMPLE_SCALE 32768.0
>
> Maybe have:
>
> #define AMR_SAMPLE_BOUND 32768.0
> #define AMR_SAMPLE_SCALE 1.0/32768.0
>
> and edit the other code accordingly so that you can use * rather than /. We
> may have some suitable dsputil function for this anyway so it's not
> massively important. Michael would have a suggestion about it later I
> expect.
>
> Regards,
> Rob

Since most of the processes are linear, I should be able to scale the
innovative vectors definitions in amrnbfloatdata.h. However, I need to
investigate what other effects this will have.

Do you have any scripts to help generate amrnbfloatdata.h except reformat.pl?