BPM for Audio files

Hi Developers, For an existing DJ music software program, we are looking for a small extension. We will put in the counter of the beats per minute (BPM). For that we need a program that will automatically count the BPM in the audio files. All the software is written in Delphi, so if you write this module it can be easily added to the existing software. If you have any questions, you're welcome. Implementation is planned in June 2009.