This plug-in was written in response to a request for counting heartbeats. I’m waiting to hear back from that user, but I think it should work quite well for that purpose.
For use with music this plug-in is extremely limited as it currently is. To be really useful it would need to have much more sophisticated beat detection. Currently it detects a beat when the amplitude exceeds the threshold value. A long sustained high amplitude sound would be counted as one beat. It takes no account of rhythm so a rhythm of “beat-rest-rest-beat” would be counted as 2 beats rather than 4. If the selection includes silence before or after the actual recording, then this will throw the BPM calculation way out.
When testing on a click track, a 60 second sample was sufficient to provide accuracy of +/- 1 BPM. I think it is necessary to have some limit on the maximum duration that is analysed, and this will be particularly true if a more sophisticated (much slower and heavier on RAM) beat detection algorithm is used, but for now I’ve increased the max up to 10 minutes which still completes in a reasonable time.
Nyquist plug-ins can only return 1 result, so a label track OR text in a dialogue box may be returned.
However, a Nyquist plug-in can return a label track (or sound) AND output text into the debug window (requires that the Debug button is pressed).