[speex-dev] Optimizing speex for 44.1kHz

Greg Herlein gherlein at herlein.com
Fri Jan 10 12:49:38 PST 2003



> > excessive... unless you really do want to do CD quality.
> 
> True, I think the best sampling rate for VoIP is probably 16 kHz.

Actually, if you are going to interface to the PSTN it's silly to
sample at faster than 8kHz since that is what you will be limited
to due to the legacy PSTN.

Personally, I think you should evaluate the additional sound
quality of sampling at 16kHz verses 8kHz against the fact that
you are doubling your needed bandwidth when you do it.  Two mode
3 compression streams sampled at 8kHz will use 8kbps each... add
about 15% for packet overhead and you use about 35kbps for a two
way conversation.  You can easily fit that across a 64k
link...  doublign your sample rate to 16kHz would no longer let
that same conversation fit across that link. 

It's a tradeoff.

Greg

<p>--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'speex-dev-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.



More information about the Speex-dev mailing list