Mixxx uses the BPMDetect class from the SoundTouch library to detect BPM. There is also another open source library called BPMDj , which is harder to use, but more accurate.
I personally would not rely on that either. Then I am again an amateur DJ, so I tend to rely more on my ears.
EDIT
There is a much better OSS library called aubio . It can also perform beat detection and start detection.
OTHER IMAGE
Mixxx has now moved to a set of VAMP plugins, which is much better, supports aubio and many other bit detection libraries. It also supports key detection and other sound analysis functions.
Phillip Whelan Sep 13 '09 at 9:51 2009-09-13 09:51
source share