[linux-audio-user] voicemail?

Eric Dantan Rzewnicki rzewnickie at rfa.org
Tue May 24 16:30:10 EDT 2005

On Tue, May 24, 2005 at 08:58:33PM +0100, anahata wrote:
> On Tue, May 24, 2005 at 02:44:04PM -0400, M P Smoak wrote:
> > In my work I use telephone in similar ways.  In both cases, phone calls
> > are data.
> [snip] 
> > But it's too big.  Saving it as a .ogg file with quality = 4 gets it down
> > to about 5 meg, I think.  So the question is what's a good way to shrink 
> > it down?
> For voice you could get away with a lower quality ogg and/or resampling
> to a lower sample rate (digital telephony itself uses 8kHz)
> For the ultimate in voce compression however, there are free GSM
> compression/decompresison tools. In debian the gsm-utils pachage seems
> to the the thing you need, no doubt will pull in all the various libgsm*
> packages too. I haven't used it, but if you can get it to do what you
> want you waon't get better voce compression.
> > what type file will it be that is easily platform independent
> Ogg vorbis is quite portable. Don't know about the GSM tools.

There is also the speex codec, also from xiph.org and wrappable in an
ogg container. It's optimized for speech.

Eric Dantan Rzewnicki  |  Systems Administrator
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