[asterisk-dev] Asterisk SVN trunk and wideband

[Matthew Fredrickson]

On May 9, 2007, at 4:25 PM, Stephen Davies wrote:
>
> Can someone clue me in about the state of play for wideband in SVN 
> trunk?

It's limited to G.722 right now, since it's really easy to do directly 
G.722<->8000hz signed linear.  There isn't a generic way of doing 
resampling.

>
> I took 2 SNOM phone and told then to do G722, dialled them through an
> svn trunk box.  sip show channels says they are using g722.  One phone
> was a '320, the other a '190.
>
> So the call didn't sound amazingly better.  bs and ps were more
> distinct I reckon but I did expect more.

You might check to see if it's being transcoded to 8000hz signed 
linear.  Reasons that would cause that to happen would be inband DTMF 
detection, and anything else you can think of that might make it 
necessary to transcode to 8000hz signed linear.

>
> So - should I hear 8kHz bandwidth?  Are there other steps I need to do?

See above.

>
> And also - what's the prospect for Speex 16kHz?

There's not a way to do that right now.

>
> And transcoding between the two?

Since there isn't a generic resampling (more specifically 8000hz signed 
linear <-> 16000hz signed linear) function in Asterisk right now, it 
cannot do anything with 16khz speex.

Matthew Fredrickson