[asterisk-users] meetme conference using g729?

[Tilghman Lesher]

On Wednesday 03 October 2007 06:09:01 Peter Fern wrote:
> Tilghman Lesher wrote:
> > Or, in other words, you cannot mix compressed data.  You must first
> > decompress the data for mixing, then recompress it for transmission.
> > During both operations, there is a potential for signal degradation.
>
> Ummm, why??  Unless you can explain some technical reason for this,
> looks like about 11 lines to change, +3 for correct log messages, +1 for
> a define, +~3 to add it as a nice config option in meetme.conf.
>
> So, in all about... 18 lines worth of code to get it running on any
> available codec, configurable from meetme.conf, which IMHO would make a
> lot of sense for single-codec systems... especially for G.729 due to
> better use of licenses, but for others too, due to load reduction and
> improved audio quality...
>
> Of course, I could be missing something obvious, please correct me if
> that's the case.

I invite you to try it.  You could make a lot of really smart people look like
fools if you're able to mix compressed audio together without decompressing,
or you might make yourself look like a fool, because you get back garbage for
attempting to mix compressed data.

While I won't go so far as to say mixing compressed audio is impossible
without decompressing first, it is not *simple* by any means whatsoever.  In
fact, I would go so far as to say that not only are you likely to degrade the
audio even further, but the CPU time it would take is an order of magnitude
higher than the current methodology.

-- 
Tilghman