Is there open source audio feature extraction software avaliable?

Question

I undertaking a personal project which involves the development of a system which will automatically generate audio thumbnail clips (about 30 seconds in length) from a full length track.

In order to do this I want to look at the energy and pitch of the audio to try and correctly identify its major structural features.

Is there any open source software available that can do energy/pitch extraction? If not I will start looking into alternative methods using MATLAB.

Thanks!