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 files fold.orc and fold.sco.
Example 153. Example of the fold opcode.
/* fold.orc */ ; Initialize the global variables. sr = 44100 kr = 4410 ksmps = 10 nchnls = 1 ; Instrument #1. instr 1 ; Use an ordinary sine wave. asig oscils 30000, 100, 1 ; Vary the fold-over amount from 1 to 200. kincr line 1, p3, 200 a1 fold asig, kincr out a1 endin /* fold.orc */
/* fold.sco */ ; Play Instrument #1 for four seconds. i 1 0 4 e /* fold.sco */