[Freeswitch-users] SRTP in PhonerLite and Freeswitch

[Brian West]

Yes that is correct.. you say 8000 but its really 16000 anyone that  
says 16000 is doing it wrong.

/b

On May 28, 2008, at 1:01 PM, Alfred E. Heggestad wrote:

> Brian West wrote:
>> What else is great is his phone does G722 wideband.  w00t!
>
> btw, what kind of G.722 wideband codec do you support?
>
> I see that you are using G.722 implementation from the "voipcodecs"
> library, and that you are using different samplerates, one signalled
> in SDP (8000 Hz) and 16000Hz as the actual DSP samplerate. Is this
> correct?
>
> From RFC 3551:
>
> 4.5.2 G722
>
>   G722 is specified in ITU-T Recommendation G.722, "7 kHz audio-coding
>   within 64 kbit/s".  The G.722 encoder produces a stream of octets,
>   each of which SHALL be octet-aligned in an RTP packet.  The first  
> bit
>   transmitted in the G.722 octet, which is the most significant bit of
>   the higher sub-band sample, SHALL correspond to the most significant
>   bit of the octet in the RTP packet.
>
>   Even though the actual sampling rate for G.722 audio is 16,000 Hz,
>   the RTP clock rate for the G722 payload format is 8,000 Hz because
>   that value was erroneously assigned in RFC 1890 and must remain
>   unchanged for backward compatibility.  The octet rate or sample-pair
>   rate is 8,000 Hz.
>
>
> ...
>
> are you planning to add G.722.1 support at some point? I guess there
> are no free implementations of this codec, yet..
>
>
> Thanx
>
>
> /alfred

Brian West
sip:brian at freeswitch.org