This is a program for stretching the 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.
Please note that this is suitable only for extreme time stretching (e.g. if have a melody of 3 minutes and you want to listen it in 3 hours). If you want "less extreme" time stretching, you can use a program which contains the SoundTouch library.
Features
* It produces high quality extreme sound stretching. While most sound stretching software sounds bad when trying to stretch the sounds a lot, this one is optimized for extreme sound stretching. So, the stretch amount is unlimited.
* You can play the stretched sound in real-time (including the possibility to "freeze" the sound) or you can render the whole sound or a part of it to audio files
* It has many post-processing effects, like: filters, pitch/frequency shifters
* Support for WAV, OGG VORBIS files and MP3 files
* It is a Free Software
Reference: http://hypermammut.sourceforge.net/paulstretch/