[asterisk-dev] OpenCL for improved performance transcoding and conferencing

[Chris Coleman]

Chris Coleman wrote:
> > The biggest drain on CPU cycles in Asterisk, appears to be 
transcoding and conferencing.

Paul Belanger wrote:
 >Why are you transcoding audio?


Asterisk -- from what I understand, and from my own experience in audio 
-- automatically decodes the audio from each conference call 
participant, so it can mix the audio together, re-encode, and transmit 
the new audio mix back to each conference participant.

You can't mix encoded (compressed) audio streams without decoding them 
first, then re-encode them!

This is essentially equal in computation to a transcode.

Also, each participant may require that the audio stream sent back to 
them be in a different audio codec from everyone else....