[Asterisk-Dev] G.722 and Grandstream

[Andrew Lindh]

>Steve Kann wrote:
>
>You do realize that G.722 audio is 16kHz, and there's code all over 
>asterisk that assumes 8kHz; even if you decode G.722, you still need to 
>resample to get 8kHz, and to encode to G.722, you'll need to resample to 
>16kHz. Then there's all the code that assumes that ms = samples/8, etc..

Yes, and that's not important.....G.722 is a 64Kbit/sec (for mode 1)
data stream. So dealing with the raw G.722 is easy because it
looks just like G.711. So with any raw G.722 it does not matter that
it's 16Khz audio. On the codec conversion side, yes it would need to be
resampled to mix and match 8Khz/16Khz. Quick and easy for testing is
to just drop or add data words to match the rate. I was not planning on
supporting raw 16Khz in asterisk at all, it would always be raw G.722 or
converted to 8Khz slin audio. Anything that it would be converted to
(for now) is 8Khz based anyway, so there would be no issue of quality loss.

In my quick test I recorded a G.722 audio stream (just from the dialplan
record function) and I can play it back to the phone (from the dialplan).
When I use an external G.722 audio encoder/decoder I don't get valid audio
from the conversion. So my big issue is I don't have G.722 codec code and
information that matches the G.722 on the BT-100 phone....

  Andrew