[asterisk-dev] iax2 mini frames and speex

[Steve Kann]

Yusuf Bey wrote:
> Hi, I'm developing an IAX client that uses Speex, and when I make a 
> call I get mini frames with 21 bytes of data. I believe Speex expects 
> 160 bytes. So I'm not sure what to do. Concatenate the 21 bytes of 
> each packet? Somehow get Speex to decode 21 bytes at a time? Thanks in 
> advance for any advice you may have.

The speex decoder does not expect 160 bytes;  it expects 160 encoded 
samples (in narrowband modes, which are the only ones defined for IAX2 
at the moment).  If that was 160 bytes, it wouldn't be very good 
compression (it would be 64kbps, just like uLaw).  21 bytes would be 
8.4kbps, which is probably the 8kbps mode + some padding.

-SteveK