fold

fold --  Adds artificial foldover to an audio signal.

Description

Adds artificial foldover to an audio signal.

Syntax

ar fold asig, kincr

Performance

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.

Examples

Here is an example of the fold opcode. It uses the files fold.orc and fold.sco.

Example 1. 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 */
        

Credits

Author: Gabriel Maldonado
Italy
1999

New in Csound version 3.56