Re: Sine wave in an envelope

Hello Jeff,


you wrote:
 > Actually I'll have both mono and stereo cases, but was asking
 > about the stereo case.  Of course I can split the stereo into two mono
 > files.  I was hoping to do it in one line, which was the real question
 > here -- the synth effect documentation says it can operate differently
 > on different channels but I couldn't figure how to make that work.

Okay, I see what you mean in the documentation for "synth" where it says
"Audio for each channel in a multi-channel audio file can be synthesised
independently".

Hmm.  I haven't checked the code, but my gut feeling is that this
multiple channel setting of the synth effect only works for _creating_
waves in different channels.

As soon as you don't have "create" as the combine operation (in your
case it is "amod)" it is hard to find out for sox whether the combine
operator should apply to the input or some previous waveform.

In general and in my opinion, sox is not very good at doing some
specific processing on single channels of an input file as in your case.
  One similar example would be a parallel compression ("New York City
compression") where a compressed signal is combined with the original:
as far as I know this only can be done with a temporary file.


          Best regards,

                  Thomas