[Asterisk-Users] What is the highest quality codec I can use for recording voice messages?

[Fats Neutron]

On 15/8/03 20:15, "WipeOut ." <wipeout at linuxmail.org> wrote:

>> Thanks for the fast reply.
>> 
>> I assume you mean that alaw or ulaw is what the carrier delivers. Because my
>> customers use the phones they have I do not have control over the carrier
>> they use, I just meant it to mean all carriers. As in what is the standard
>> format they deliver in.
>> 
>> I assume that I have no control over how they deliver but at the Asterisk
>> end I wanted to ensure the highest quality recording.
>> 
>> If I used a direct connection from one computer to asterisk could I increase
>> the quality by using a different codec, assuming they have broadband access
>> at their end. I have read that the g711 is the highest quality in the sample
>> rate but was not sure if this would still work with Asterisk or if I should
>> use G729 as it seems to be double the bandwidth sampling at between 8 and 12
>> kps whereas g711 seems to sample at 64kbs but that may flood the connection.
>> 
>> Any ideas?
>> 
>> Thanks
>> Fats.
>> 
> 
> Basically G.711 applies the least amout of compression and therefore the least
> amout of quality loss.. similarly G729 applies a very high level of
> compression so in theory would have a high quality loss..
> 
> Unfortuantely its not always that simple as not all codecs are created equal..
> :)
> 
> And as you said the G.711 having the highest quality also has the highest
> bandwidth requirement of 64Kbps (this increases to just over 80Kbps after you
> add IP overhead) so if you can sustain that leavel of throughput then the use
> of G.711 is irrelevant..
> 
> Like I said if you are really concerned then the best way is to test it and
> then listen to the results and see if you are happy with it..
> 
> Later..

Yes you probably right.
Test and see.

So how do I get and use each codec to test them. I understand some are under
tight copyright control. Do they have testing variations rather than buying
first, find it it does not work, and your stuck with the cost?


Thanks for you help.

As always a fast reply.
Thanks

Fats.