SoundTouch is an open-source audio processing library that allows changing the sound tempo, pitch and playback rate parameters independently from each other:
* Change **tempo** while maintaining the original pitch
* Change **pitch** while maintaining the original tempo
* Change **playback rate** that affects both tempo and pitch at the
Ready [SoundStretch application executables](https://www.surina.net/soundtouch/download.html) are available for download for Windows and Mac OS.
## Language & Platforms
SoundTouch is written in C++ and compiles in virtually any platform:
* Windows
* Mac OS
* Linux & Unices (including also Raspberry, Beaglebone, Yocto etc embedded Linux flavors)
* Android
* iOS
* embedded systems
The source code package includes dynamic library import modules for C#, Java and Pascal/Delphi languages.
## License
SoundTouch is released under LGPL v2.1:
This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License version 2.1 as published by the Free Software Foundation.
This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
See [LGPL v2.1 full license text ](https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html) for details.
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Also commercial license free of GPL limitations available upon request