[Asterisk-Dev] 16 KHz audio ?

[Andrew Lindh]

Here are some other G.722 versions:

Codec	ITU yr	type		delay	rate
G.722	1988	SB-ADPCM	2ms	48 56 64k
G.722.1	1999	Transform?	20ms	24 32k
G.722.2	2002	ACELP		20ms	23.85 down to 6.6k

G.722.2 is also known as AMR-WB which looks good on paper. But again
the patent pool has a deep end and it's not cheap...

While G.722 may be free and easy it is not the advanced codec that
most people will be looking for. G.722 and it's additions are
rather different from each other, I don't know what the phones
support today. They may support only newer versions.

Speex may offer some more features and quality, but hardware support
seems limited (or non-existant?)....It's easy to install (with a few
simple changes to the makefile it's fine).



>That is the obsolete G.722 It is too old to have patent protection, but 
>too nasty to be interesting. It was part of the original definition of 
>ISDN, and was supposed to be the PSTN's path to an all 7.1kHz bandwidth 
>future. It never happened. The 10MIPs figure is for a DSP chip. It is 
>probably 50-60MIPs on a Pentium (just an educated guess).
>
>G.722.1 is the current standard, but it is recent and patented (i.e. the 
>patents will not expire any time soon).
>
>Regards,
>Steve