[linux-audio-announce] Announcing ClearScale: Open Source Commercial-Grade Time Stretching/Pitch Shifting Project

[Stephan M. Bernsee]

Announcing ClearScale:
Open Source Commercial-Grade Time Stretching/Pitch Shifting Project

ClearScale is an open source GPL-based project to bring high quality 
time stretching and pitch shifting to the Linux platform. The goal is 
to create an open standard for a commercial grade algorithm that allows 
changing the pitch and speed of music and sound independently of each 
other. It should achieve this in an artifact-free, sonically pleasing 
manner, comparable to commercial algorithms on the MacOS and Windows 
platform available today.

The algorithm should work equally well with musically monophonic and 
polyphonic material over a wide range of scaling ratios, and it should 
encompass a way to compensate for the formant shifts ("Mickey-Mouse 
effect") that occur during pitch shifting.

It is hoped that an open standard  for such an immensely important 
integral part of audio processing will make Linux-based audio 
processing both easier and more popular. The algorithm should be 
designed to serve as a quality reference for other algorithms in the 
field, and a suite of audio files and test signals will be provided 
with it to serve as a testbed for other future algorithm designs.

The project is initiated by Stephan M. Bernsee (formerly Stephan M. 
Sprenger) who maintains a highly popular educational web site about 
time stretching and pitch shifting and related topics at 
http://www.dspdimension.com. He has authored several commercial 
solutions on the MacOS and Windows platform and his papers and 
algorithms are part of lectures on DSP at several universities and 
online courses.

The project has initially been funded by a private research grant and 
its running costs will be financed through PayPal donations to its 
maintainer. More information on its current status, design goals and a 
FAQ can be found on the project web site, http://www.clearscale.org