[SoX-users] step backward in file for effects proessing?

[forget c. <for...@gm...>]

I want to reprocess parts of a file after I already did something to it.

For example, let's say I have a 5 second file and I want to adjust the
speed of seconds 0-3 to 1.02 and, after that adjustment, I want to adjust
the speed of seconds 0-2 to .98. So in trim notation what I'd want is
something like:

   play in.wav trim 0 3 speed 1.02 : trim -3 3 speed 0.98

But I can't use a negative number as the first input to trim.

I could accomplish it with this:

  sox in.wav tmp1.wav trim 0 3 speed 1.02
  sox tmp1.wav out.wav trim 0 3 speed 0.98

But is there a way to do this in one command? I don't just want it for one
step back but constantly over an entire file.

thx
fg