SoX (Sound eXchange) is a cross-platform command line program for doing things with audio.
It can be used to convert between different audio formats, trim, join and mix files, add effects, play and record files, change sample rates and bit depths and many other common audio tasks. It is sometimes likened to a command line sibling to Audacity.
One of the great strengths of SoX is that as a command line utility it can easily be used with batch processing scripts.
Today I have been looking at the “Compander” effect because I had need of an aggressive, fast compressor/limiter effect.
A brief summary of the available commands is given by:
sox -h
A brief summary of the effects commands is given by
sox --help-effect <effect>
so for the Compander the brief help can be shown with:
sox --help-effect compand
This gives:
sox: SoX v14.3.1
Effect usage:
compand attack1,decay1{,attack2,decay2} [soft-knee-dB:]in-dB1[,out-dB1]{,in-dB2,out-dB2} [gain [initial-volume-dB [delay]]]
where {} means optional and repeatable and [] means optional.
dB values are floating point or -inf'; times are in seconds.
I found this to be a bit more than slightly cryptic, so I looked in the SoX manual http://sox.sourceforge.net/sox.html#index
… more to follow