On 29-Jan-08, at 2:11 PM, Ben Wheeler wrote: > On Fri, Jan 25, 2008 at 09:25:18AM -0500, Albert Santoni wrote: >> I think we can make it _much_ easier to do in Mixxx (we can take >> advantage of our BPM detection). > > Something along the lines of the CDJ400/800's Auto Beat Loop, which > creates a loop for 1,2,4 or 8 beats that you can then subdivide by > 1/2, 1/4 or 1/8.
Yeah, my KP3's sampler works similarly. (easy to use) > > > The difference is, however, that our BPM detection still sucks > compares > to Pioneer's, so I think a prerequisite of a useable autolooper is a > better Tap function which intelligently adjusts the beat marks and > informs the beat marking engine how to do its job better for this > track > (in a way it'll remember next time!) rather than just updating the > BPM. > I haven't seen a BPM detection algorithm that fairs significantly better than ours. If you want to improve the BPM tap, I'd invite you to hack it. The way these BPM tap-assisted detection algorithms work is they simply use the BPM tap guess to narrow the range of BPMs to look at. Rough algorithm: 1) Get user to tap to the BPM 2) Smooth over their taps, do some standard deviation calculation 3) Tell the BPM detection to search within +- std. dev. 4) you're done (This is exactly how it works on my KP3. Does Pioneer's algorithm work better than Mixxx's _without_ any extra bpm-tap assist?) Micah's awesome improvements/reworking of our BPM detection already allows us to specify a range of BPMs for the algorithm to look within. It's probably a good weekend project to hack the BPM tap to feed into that range... Albert ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Mixxx-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mixxx-devel
