Re: newbie question on cglame

[Richard G. <rg...@ta...>]

On Wed, 8 May 2002, Brian Lindholm wrote:

> Gentlemen,
> 
> Earlier this evening I successfully compiled glame-0.6.2 on my Debian
> 2.2r6 box.  I'm hoping to use cglame to run a *large* number of sound
> files through a low-pass filter for purposes of lessening tape hiss.
> 
> Unfortunately, I'm completely unfamilier with Scheme, and my efforts to
> run even a single .wav file through a low-pass filter are failing miserably.
> How do I do this in cglame?  If somebody could provide a sample
> command sequence that would run a single .wav file through the low-pass
> filter, I'd be enormously appreciative.

You can use the pre-defined save-eff scheme procedure for this. Example
use for lowpass filter use is

cglame> (save-eff "test.wav" "test_filtered.wav" '("lowpass" ("stages" 4)
("cutoff" 500) ("ripple" 0.5)))

Note that you need to change all occurrences of filter-set-param to
filter-set-param! in src/glmid/glame.scm (applied this bugfix to the
v0_6 branch already). Also you may want to change the (net-run net)
part of the save-eff procedure to (net-run net (* 64 1024)) and adjust
the net-run definition to read

; run the net, wait for completion and delete it
(define net-run
  (lambda (net . bufsize)
    (if (null? bufsize)
	(filter-launch net)
	(filter-launch net (car bufsize)))
    (filter-start net)
    (filter-wait net)))

to speed up computation (it sets larger buffer size for processing,
default buffer size is 1024 if I remember correctly).

Hope this helps, Richard.

Btw. all the above changes went into the v0_6 branch.

--
Richard Guenther <ric...@un...>
WWW: http://www.tat.physik.uni-tuebingen.de/~rguenth/
The GLAME Project: http://www.glame.de/