Re: [SoX-users] compand usage

[Nicola L. <ni...@te...>]

 > Where might I find some information on the usage of the
 > compand function?
 >
 > I'm educated in DSP, but inexperienced in audio processing.

I am well versed in audio processing, and have the same need currently. What
I need is exactly the compand application detailed in the soxexam man page
of the 12.17.3 version, that is, compressing tracks for car use.

Unfortunately I cannot seem to make it working well. :^(

I upgraded the SoX version in Mandrake 8.2 from 12.17.1 to 12.17.3
suspecting some bug, but result have not changed.

My reference is the Cooledit Windows program, where things work just fine.

I tried a few transfer function, i.e. the following command lines:

$ sox in.wav out.wav compand 0.001,0.5 -60,-20,0,0
$ sox in.wav out.wav compand 0.001,0.5 -80,-20,0,0
$ sox in.wav out.wav compand 0.001,0.5 -90,-10,0,0

By the way, from the source it seems that the attack and decay times are 
expressed in seconds, but the result is always too "flat", as if the times 
are much longer.

Only the last line gives a result resembling what I need, that is 3:1 
compression above -60dB , but the stereo image flutters and I hear too much 
noise pumping.

Nick Bailey, are you there?


-- 
Two witches watch two watches. Which witch watched which watch?

Nicola Larosa - ni...@te...