[CM] snd config, help
Mon, 20 Nov 2006 11:25:06 -0800
> 1. to visually see or other way detect clipping (or identify
> lossy coding)
Here's a function that looks for clipping:
(define* (channel-clipped? :optional snd chn)
(let ((last-y 0.0))
(let ((result (and (>= (abs y) 0.9999)
(>= (abs last-y) 0.9999))))
(set! last-y y)
0 #f snd chn)))
On the mpeg filtering -- I haven't paid much attention to that
business, so I don't know exactly what to look for, but presumably
you could take a spectrum and look for the mpeg signature.
> 2. do "Hard Limiting" (I don't know how to do it in snd)
I don't know what "hard limiting" means.
> 4. Identify digital silence in audio
I usually use some form of moving-average for this -- map-silence
in extsnd.html for example.