Has anyone figured out a way to do BPM/Tempo detection of loops in Reaktor?

Check the midi library, it's easy to calculate the current tempo. I've done it several times over. Unless your using a wave file with or something. I have a tempo tap finder too, it works by ear ,, just tap to the music. It's easy, make a sample ramp that resets when you tape. Grab the current ramp value when a button is pressed and do the math to find the tempo. Then reset the sample ramp, easy as pie. Also rig it so the ramp doesn't self start and holds at zero samples until your first tap. If you do that, it makes it easy to average your tap readings once you start tapping. I use it to find the tempo of a song for setting the daw tempo. Same principles apply if your analyzing a wave file. Sensing the beat of something to replace the button might be a problem if you need to do it in real time though.

Another thing might be to envelope follow then downsample a lot, then use a long fft... but not tell the fft that the data is downsampled. .. then decode/select the loudest frequency... then scale that to get the tempo. That might get you in a good ballpark to make the auto correlation quicker... dunno... might even be an alternative...

Michael, do they tell you the length of the loops? Are you aware of the song position pointer?

Well, they're loops aren't they. So the play for a certain amount of time then start over. If you know the length of time you can calculate the tempo. One beat per second is tempo of 60 beats per minuter. So if the loop last for one second before looping it's tempo is 60. Maybe a loop last for 4 seconds, So is it still a tempo of 60? Maybe, if the loop is four beats long. Seems to me loops should already have a tempo and the number of beats included with the loop meta data.

hmm... that's going to be tricky. Depending on the feel, where the kick is, double time... whatever. To be 100% accurate, you would maybe need to create an AI and teach it to recognise genre, then get into arguments with it when it still gets it wrong... at least in your opinion ;)

Is there any meta data on those loops? Maybe convert the loop file into a text file and read it. They way I see it, it almost has to be there in order to be imported into different tempo's. I know Chet Singer said he once imported wave files but had to strip off the header. I'm pretty sure he imported them into a read only memory module and not the reactor player. Perhaps you should take his approach and do the same. It will give you precise control, you'll be able to calculate the tempo too. However as I said before, sadly I don't have a clue what you are trying to do. Can you help me out here. The only beat slicer I know of is some video game that throws balls or something at your sword and when you chop em they make some wild sound. A lot of people really like that game but being a musician I don't think it would be very impressive. Believe me, I'd like to help out but without knowing what you're doing it's impossible. I do feel there's a better approach. Are you simply trying to find the tempo of a loop? If so, just play it and while it loops tap a button in time with it. Average the time between taps and you get your tempo. I doubt making a tap tempo in core will be difficult. It's possible your daw already has one.