rt_pvc :
real-time phase vocoder analysis/synthesis library + visualization

authors: Ge Wang | Ahmed Abdallah | Paul Botelho
date:Spring 2004
version: 1.0

rt_pvc is a:

  • real-time phase vocoder library for synthesis/analysis
  • vocoder application that allows the user to do time-expansion, frequency expansion, and cross-synthesis in real-time, from mic-input or from file.
  • real-time phase vocoder visualization
  • learning tool that teaches about the phase vocoder and its implemementation
  • open source!

rt_pvc runs on MacOS X, Linux, and Windows.

download rt_pvc
(you need OpenGL/GLUT):

get source (v1.0.0) (all platforms)
or just get the MacOS X executable
or the file-enabled MacOS X executable


  > rt_pvc [-w initial window size=1024]
           [-h initial hop size=128] 
           [-t initial time factor=1.0]
           [-f initial freq factor=1.0]
           [-x cross synthesis input file]

real-time keyboard control:
  's' - toggle fullscreen
  '-' - decrease frequency factor
  '=' - increase frequency factor
  SHIFT('-') - decrease time factor
  SHIFT('=') - increase time factor
  '(' - decrease hop size
  ')' - increase hop size
  'p' - toggle phase adjustment

  'd' - toggle dB plot
  'w' - toggle wuterfall
  L|R mouse - rotate
  '[' - rotate
  ']' - rotate
  'g' - freeze the simulation
  'q' - quit
  'h' - print help

more phase vocoder references
  • Gotzen, A.D., N. Bernardin, D. Arfib. 2000. "Traditional Implementations of a Phase-vocoder: The Tricks of the Trade." In Proceedings of DaFX.
  • Flanagan, J. L. & R. Golden 1966. "Phase vocoder." Bell System Technical Journal, 45, 1493-1509.
  • Moore, J. A. 1978. "The Use of the Phase Vocoder in Computer Music Applications." Journal of the Audio Engineering Society 24(9), 717-727.
  • Dolson, M. 1987. "The Phase Vocoder: A Tutorial." Computer Music Journal 10(4):14-27.

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