[Asterisk-Users] G729 Codec

[steve at daviesfam.org]

On Tue, 3 Aug 2004, Steve Underwood wrote:

> Eh? G.729 has no particular features to allow more effective packet loss 
> concealment. iLBC has, but at the cost of a substantially higher bit 
> rate. In fact G.711 is a little ahead of G.729 in the regard, since 
> packets are completely independant. The smoothing in G.729 means you 
> need the previous packet to decode the current one properly.

For IAX2, at least, Asterisk oes not use the lost-packet-concealment of 
any codec.  This is because the incoming frames "clock" Asterisk.  For 
iLBC's lost packet concealment to work, Asterisk would have to start 
calling the decoder with a NULL at the point when the missing packet shold 
have arrived.

Can't say for sure for SIP, but I'd guess that its the same.

Steve