Time stretching and pitch scaling

[Altaryan]

Hi everybody !!

I have a work to do about audio modifications, and more particularly, about time stretching and pitch scaling algorithms.
Could you explain me how these algorithms work, because audacity can do it, but i need a mathematic explication of this.

If a developper (or other) want to contact me: altaryan at hotmail dot fr

Thanks.

Altaryan

[steve]

Audacity uses Libsoundtouch.
A good place to start your search would probably be here: http://www.surina.net/soundtouch/
There is a basic introduction in the README http://www.surina.net/soundtouch/README.html
For more detailed information you will probably need to study the source code and examples, or speak to the soundtouch developers.

By the way, posting your e-mail address on a public forum is an open invitation to spammers - it may be wise to edit your previous post.