ACELP | ADPCM | AMBE | AMR | AMR-NB | CELP | Codebook | DTMF | G.723 | G.726 | G.729 | GSM | Interpolation | LPC | LSF | LSP | MELP | PCM | Perceptual | Pitch | PSOL | QCELP | Quantization | SMV | VAD | Vocoder

Hello,

I am implementing a simple mixing program (i.e. create a new sound 
file combinig two initial files - all the same format). I have 
implemented this for WAV files (PCM) and now I want to support AMR. I 
can do this in 2 ways:

1. convert to PCM and reuse the mixing code - I cannot find any 
documentation on how to convert an AMR frame to PCM samples. What 
happens after I reorder the bits and obtain the 3 classes (A, B and 
C) ?

2. directly mix 2 AMRs frame by frame - I have no ideea how to do this.

Any help is welcome,
Thanks

Horia

______________________________
New Year Gift for Members of DSPRelated.com.  Details here.

(You need to be a member of speechcoding -- send a blank email to speechcoding-subscribe@yahoogroups.com )

To my limitted knowledge, direct mixing of 2 signals in coded domain 
is some what impossible. The best I think one can hope for is 
skipping the post filtering at the decoders.

--- In s...@yahoogroups.com, "horiaciu" <methhane@...> wrote:
>
> Hello,
> 
> I am implementing a simple mixing program (i.e. create a new sound 
> file combinig two initial files - all the same format). I have 
> implemented this for WAV files (PCM) and now I want to support AMR. 
I 
> can do this in 2 ways:
> 
> 1. convert to PCM and reuse the mixing code - I cannot find any 
> documentation on how to convert an AMR frame to PCM samples. What 
> happens after I reorder the bits and obtain the 3 classes (A, B and 
> C) ?
> 
> 2. directly mix 2 AMRs frame by frame - I have no ideea how to do 
this.
> 
> Any help is welcome,
> Thanks
> 
> Horia
>

______________________________
New Year Gift for Members of DSPRelated.com.  Details here.

(You need to be a member of speechcoding -- send a blank email to speechcoding-subscribe@yahoogroups.com )