wsola(1) program to stretch and compress (speed up/slow down) audio without altering its pitch.


wsola inputFile outputFile factor


wsola speeds up or slows down audio, without pitch alteration. The two files input/output are accessed using the libsndfile library and thus may be in many formats supported by libsndfile.
The input argument 'factor' specifies the output speed of the audio. Factors > 1 imply slowing of audio. Factors < 1 imply the speeding up of audio. For example a factor of 0.5 will double the speed of the audio. A factor of 2.0 will halve the speed of the audio. A factor = 1.0 will leave the audio unaltered.
WSOLA operates using the Waveform Similarity overlap add method [1]. For more information on the signal processing employed by WSOLA please read the file 'hybridDomainProcessing.pdf'.


wsola was written by Matt Flax <[email protected]>.


[1] @InProceedings{Verhelst:1993,
  author =       {Verhelst, W. and Roelands, M.},
  title =        {An overlap-add technique based on waveform similarity (WSOLA)  for high quality time-scale modification of speech},
  booktitle = {IEEE International Conference on Acoustics, Speech, and Signal Pr ocessing},
  pages =        {554-557},
  year =         {1993},
  volume =       {2},
  month =        {April} }