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 for processing .wav audio files from command-line interface.
Access the source codes in gitlab or download the compiled executables.
BestPractice is a musician’s practice tool, to slow down or speed up music, either from an MP3 file or directly from a CD. Ordinarily the sound is distorted when slowed down our sped up – you get the effect like when playing a 33 rpm record on 45 rpm speed (remember the Chipmunks?). BestPractice tries to correct this, so you can slow down and speed up music, while keeping the original pitch. It is also possible to change the pitch of the music without affecting its tempo. Play along with for instance Eb tuned guitars without retuning your own, or slow down that high-speed guitar solo on a CD that you like to learn.
This is a program for stretching audio. It is suitable only for extreme sound stretching of the audio (like 50x) and for applying special effects by “spectral smoothing” the sounds. It can transform any sound / music to a texture. The program is Open-Source and it’s released under the version 2 of the General Public License. You can download the source code for Linux or the Windows binaries.