[Asterisk-Dev] Help with integrating EVRC codec into Asterisk

[Kevin P. Fleming]

gourij at qualcomm.com wrote:
> We have been playing around with asterisk code to integrate EVRC codec 
> into Asterisk.  Since EVRC encoding of current frame dependents on 
> previous frames, it is necessary to pass some call-id kind of 
> information into the codec.  From a quick look, it seems like the 
> call-id info is not sent outside of chan_sip.  How does it work for 
> other non-frame-independent codecs in Asterisk?

I don't think there are any codecs like that supported in Asterisk right 
now, except for video, and those codecs deal with this problem 
themselves (and Asterisk does not support video transcoding, so it 
doesn't have to deal with this problem).

I would think the best way to deal with this will be to allocate a 
"handle" to a codec instance when transcoding EVRC is needed, so the 
codec itself can maintain a buffer of previous frames for that stream.