[linux-audio-user] How can I time-stretch the sound like this (with SND & CLM)

[Kjetil S. Matheussen]

Paul:
>Hi.
>I found out a very interesting page and a webcast
>about the 9'th symphony of Beethoven stretched to 24
>hours here:
>http://www.park.nl/park_cms/public/index.php?thisarticle=118
>And on this page ( http://www.notam02.no/9/tech.htm )
>I found that for this was used CLM and SND.
>How can I do the same?

Its just a simple granulate processing with a tiny bit of reverb on top.
Halfly pseudo, it can look like this:

(let* ((read0 (make-readin filename #:channel 0))
        (read1 (make-readin filename #:channel 1))
        (gr0 (make-granulate #:expansion 22.0 #:length 0.15 #:hop 0.03))
        (gr1 (make-granulate #:expansion 22.0 #:length 0.15 #:hop 0.03)))
   (do-X-number-of-times
    (output-to-file file-object (granulate gr0 (lambda () (readin read0)))
                                (granulate gr1 (lambda () (readin read1))))))


Very simple. You have to tune the length and hop sizes though, plus volume 
and stuff.
http://ccrma.stanford.edu/software/snd/snd/clm.html#granulate



> It's possible to do this in
> batch mode?

Yes, the first first version of this stretch was actually run in batch 
I didn't want to stay up all night generating all the files. :-)