[vorbis] Chat with ogg

[Craig Dickson]

Olaf Marzocchi wrote:

> The last week, after 5 minutes of astonishment for the great compression 
> ratio achieved by ogg (370MB wav of voice -> 14 MB OGG, 28 kbps without any 
> perceivable and/or significant quality loss), I had the idea of use ogg to 
> stream my voice, in order to chat in almost-realtime with a friend (only 
> one, of course: I have a 56k modem).

You're probably really talking about Vorbis (the codec) rather than Ogg
(the framing layer).

Vorbis is designed for music, not spoken words. It certainly can
compress voice signals, but a codec designed for voice will do a better
job. Additionally, as I understand it, Vorbis's latency is uncomfortably
high for realtime two-way speech.

You might want to look at the Speex codec, which is a patent-free, open
source voice codec that uses the Ogg framing layer:

   http://speex.sourceforge.net

Speex can do a very good job with voice data at bit rates as low as 5
kb/sec, and supports rates as high as 30 kb/sec when you want the best
quality and you have the bandwidth to support it.

Craig

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