[SoX-users] --plot versus audio processing

[Jan S. <ha...@st...>]

The --plot function of sox has been very useful to me,
mainly in tweaking the compand parameters.

When using the plot function no actual audio is processed,
as the manpage clearly describes:

         For the  first  given  effect  that supports  the  selected
         plotting program, SoX will output commands to plot the effect's
	 transfer func- tion, and then exit without actually processing
	 any audio.

So I usually end up running sox twice, as in:

(1)	sox                in.wav out.wav compand [arguments]
(2)	sox --plot=gnuplot in.wav -n      compand [arguments]

to both hear the results of the compansion
and see the transfer function plotted.

I suppose it is a design decision for 'sox --plot' not to do
any audio work, just plot functions. But when I run

(3)	sox --plot=gnuplot in.wav out.wav compand [arguments]

then not only is no audio processed,
but out.wav gets deleted if it already exists.
Is this intentional?

	Jan