follow2 — Another controllable envelope extractor.
asig -- the input signal whose envelope is followed
katt -- the attack rate (60dB attack time in seconds)
krel -- the decay rate (60dB decay time in seconds)
The output tracks the amplitude envelope of the input signal. The rate at which the output grows to follow the signal is controlled by the katt, and the rate at which it decreases in response to a lower amplitude, is controlled by the krel. This gives a smoother envelope than follow.
Here is an example of the follow2 opcode. It uses the file follow2.csd, and beats.wav.
Example 313. Example of the follow2 opcode.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform -odac ;;;realtime audio out ;-iadc ;;;uncomment -iadc if realtime audio input is needed too ; For Non-realtime ouput leave only the line below: ; -o follow2.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 32 nchnls = 2 0dbfs = 1 instr 1 asig soundin "beats.wav" outs asig, asig endin instr 2 ;using follow2 as soundin "beats.wav" af follow2 as, p4, p5 ar rand 44100 ;noise ; "beats.wav" provides amplitude for noise asig balance ar, af outs asig, asig endin </CsInstruments> <CsScore> i 1 0 2 i 2 2 2 0.001 0.01 ;quick attack & deacy i 2 5 2 0.1 0.5 ;slow attack & deacy e </CsScore> </CsoundSynthesizer>