[Asterisk-Dev] 16 KHz audio ?

[Alessandro Gatti]

We should also bear in mind that most videoconferencing systems already
support G.722. G.722.1 (I believe it is also called "Siren") is only
supported in Windows Messenger and Polycom systems, it does have several
patents and it is subject to the licensing terms as G.729A and G.723.1.

In the view of an open source project, where I see most people liking G.711
and codecs such as GSM 6.10, LPC-10, iLBC and Speex primarily because of the
licensing issues, I would vote for G.722 for a number of reasons:

- it does require supporting 16KHz audio which is req	uired in any case by
any wideband codec
- it is fairly low complexity (similar to GSM) and therefore can be
supported in embedded platforms
- as Andrew just said, it is the same bandwidth as G.711, which most people
are happy with, with quantifiably better quality.

Once the first step of supporting it is done, we can add others (SpeexWB,
G.722.1, G.722.2/AMR-WB) as needed.

G.722 is the G.711 of wideband audio.

Best,

Alessandro

-----Original Message-----
From: asterisk-dev-bounces at lists.digium.com
[mailto:asterisk-dev-bounces at lists.digium.com] On Behalf Of Dorn Hetzel
Sent: Sunday, December 19, 2004 6:43 PM
To: Andrew Lindh; Asterisk Developers Mailing List
Subject: Re: [Asterisk-Dev] 16 KHz audio ?

On Fri, Dec 17, 2004 at 05:15:24PM -0500, Andrew Lindh wrote:
> 
> 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.
>

I think Grandtream does the old G.722, at least from what
the bit rate seems implied to be...  I don't mind 64K, I
use G.711 now, so it would be no more bits and better sound :)

-Dorn
 
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