[Freeswitch-dev] Merging A Law Audio data

[Steve Underwood]

On 06/29/2010 09:38 PM, Anthony Minessale wrote:
> you either have to decode them and merge them together by adding the 
> samples or know some kind of dsp trick to do it while its encoded.
There isn't really a DSP trick you can use. You could use a 64k entry 
look up table, but otherwise you decompress the A-law, add with 
saturation, compress to A-law and send it.

Steve

>
>
> On Mon, Jun 28, 2010 at 4:34 AM, Achim Stamm <stamm at lyth.de 
> <mailto:stamm at lyth.de>> wrote:
>
>     Hello!
>
>     I have following problem:
>
>     I get 160 Bytes Audio data (Format PCM A Law) from a Free Switch
>     Session
>     and save the data in a byte vector.
>     At same time i get 160 Bytes Audio data (Format PCM A Law) from an
>     external program and save the data in a byte vector.
>     I want to merge the two audio data like a conference FreeSwitch
>     Session
>     mixed them.
>     Can I use a Free Switch audio - Merge (C ++)  Function ?
>     How does Free Switch merge Audio Data in Conference mode ?
>
>     regards
>
>     Achim Stamm
>
>     --
>     Achim Stamm, Dipl.-Inform. (FH)
>
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> -- 
> Anthony Minessale II
>
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