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SoundTouch Audio Processing Library

The latest stable release is 1.9.0 released on 18-May-2015. See README for release details.

About the SoundTouch library

The SoundTouch Library Copyright Olli Parviainen 2001-2015

SoundTouch is an open-source audio processing library for changing the Tempo, Pitch and Playback Rates of audio streams or audio files. The library additionally supports estimating stable beats-per-minute rates for audio tracks.

  • Tempo (time stretch): Changes the sound to play at faster or slower tempo than originally without affecting the sound pitch.
  • Pitch (key) : Changes the sound pitch or key while keeping the original tempo (speed).
  • Playback Rate : Changes both tempo and pitch together as if a vinyl disc was played at different RPM rate.

The SoundTouch library is intended  for application developers writing sound processing tools that require tempo/pitch control functionality, or just for playing around with the sound effects.

The SoundTouch library source kit includes also an example utility SoundStretch that uses SoundTouch library for processing .wav audio files from command-line interface.

More information:

SoundTouch library Features

  • Efficient C++ implementation of time-stretch, pitch-shift and sample rate transposing routines.
  • Full source codes available for both the SoundTouch library and the example application.
  • Clear and easy-to-use programming interface via a single C++ class.
  • Support 16bit integer and 32bit floating point mono/stereo/multi-channel audio formats
  • Capable of real-time audio stream processing:
    • input/output latency max. ~ 100 ms.
    • Processing 44.1kHz/16bit stereo sound in realtime requires a 133 Mhz Intel Pentium processor or better ;-)
  • Portable implementation: The SoundTouch library compiles for any processor and OS platform supporting GNU C compiler (gcc) or Visual Studio, for example Win32, Mac OSX, Linux & other *nixes, Raspberry Pi, Android, iOS...
  • MMX & SSE instruction set optimizations for x86 processors
  • Compiled executable binaries supplied for Windows & Mac OS
  • Released under the GNU Lesser General Public License (LGPL) v2.1

Contact Information

Author contact information.

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Copyright © Olli Parviainen