fold — Adds artificial foldover to an audio signal.
asig -- input signal
kincr -- amount of foldover expressed in multiple of sampling rate. Must be >= 1
fold is an opcode which creates artificial foldover. For example, when kincr is equal to 1 with sr=44100, no foldover is added. When kincr is set to 2, the foldover is equivalent to a downsampling to 22050, when it is set to 4, to 11025 etc. Fractional values of kincr are possible, allowing a continuous variation of foldover amount. This can be used for a wide range of special effects.
Here is an example of the fold opcode. It uses the file fold.csd.
Example 311. Example of the fold 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 fold.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 32 nchnls = 2 0dbfs = 1 instr 1 asig poscil3 .8, 400, 1 ;very clean sine kincr line p4, p3, p5 asig fold asig, kincr outs asig, asig endin </CsInstruments> <CsScore> ;sine wave. f 1 0 16384 10 1 i 1 0 4 2 2 i 1 5 4 5 5 i 1 10 4 10 10 i 1 15 4 1 100 ; Vary the fold-over amount from 1 to 100 e </CsScore> </CsoundSynthesizer>