[asterisk-users] cpu usage for G.729 codec

[Matthew Rubenstein]

(Note: resending with proper Subject)

	If I use Asterisk to initiate two call legs with a callfile, dialing
the channel and setting the extension to an AGI that dials another
channel, and both dial by SIP connection to a switch that allows only
G.729, do I need a G.729 codec running on Asterisk? Do I need 2?

	And if I use the callfile to connect by SIP to a switch that allows
only G.729, then use the extension AGI to play a file pre-encoded in
G.729, do I need a codec? Where is the SW that encodes files in G.729?


On Thu, 2007-05-17 at 08:38 -0700,
asterisk-users-request at lists.digium.com wrote:
> Date: Thu, 17 May 2007 11:22:17 -0400
> From: "Race Vanderdecken" <asteriskusers at codetyrant.com>
> Subject: RE: [asterisk-users] cpu usage for G.729 codec
> To: "'Asterisk Users Mailing List - Non-Commercial Discussion'"
>         <asterisk-users at lists.digium.com>
> Message-ID: <01d101c79897$2c802df0$0e01a8c0 at PressonMobile1>
> Content-Type: text/plain; charset="us-ascii"
> 
>  
> G.729 is a compromise of bandwidth vs. CPU power. It takes more CPU
> but
> less bandwidth.
>  
> It depends on what your want to do with the G.729. 
>  
> Pass through does not involve any transcoding, that I know of, so it
> is
> just an RTP packet movement, no different than the cost of other pass
> through codecs.
>  
> I did work on converting G.729 to G.711 to disk storage in real time
> and
> that took about 3% of a Xeon CPU for full duplex.
>  
> Memory wise each convert call might have used 640KB in buffers and
> trash, but not much. 
-- 

(C) Matthew Rubenstein