[CM] Resampling in SND

Kjetil S. Matheussen k.s.matheussen@notam02.no
Tue, 22 May 2007 10:04:33 +0200 (CEST)

On Tue, 22 May 2007, e deleflie wrote:

> I have to admit that I am stumped by src-sound .... I cant for the
> life of me work out how to resample a file from 48000 to 44100 ....
> I've read the documentation a dozen times, but I still dont understand
> what is expected from the parameters.
> src-sound (num-or-env :optional base snd chn edpos)
> The documentation says "The argument 'num-or-env' can be either a
> number or an envelope. In the latter case, 'base' sets the segment
> base ...."
> It is never stated what the first case ('num') is supposed to
> represent. I've tried putting 44100 ... assuming that 'num' is
> supposed to be the new sample rate. But this gives clearly incorrect
> results.

"num" is the sample rate change factor. So to go from 48000 to 44100, you 
set "num" to 44100/48000.

> Also, what is meant by the segment base?

Thats the "base" argument for make-env.

> Are there any examples anywhere?

Yes, lots of:

grep make-src *