On Sun, 2012-05-27 at 14:06 +0300, zestoi wrote: > > > > i'll hack some code into mixxx just to experiment and compare the > clocks stability to traktor and ableton. since most (all?) apps won't > have higher than 1ms accuracy when decoding midi clock they have no > choice but to average out over a number of clock ticks to find the > real bpm anyway. you certainly can't just assume that the delay > between any two is an accurate 1/24th of a beat.
This is my sense as well, that midi is full of uncertainty and compromises and a certain amount of jitter is inevitable. Midi clock in/out is (hopefully) going to be part of my master sync work. Master sync should be in by 1.12 although I don't know if midi will be done in time for it. It should be fairly easy to implement, though. Mixxx will have a master sync object that not only knows what bpm mixxx is running at but also where in the beat Mixxx is at any given moment (expressed as "percent distance from the last beat"). Midi clock out will just be a matter of connecting this object to a thread that talks to midi and has its own timer. Midi clock in will be even easier, because it will just have to listen to the ticks and set its bpm and beat-distance values from them. You can check out my branch here: lp:~ywwg/mixxx/master_sync (https://code.launchpad.net/~ywwg/mixxx/master_sync) There are currently some hacks in it because there's no UI to set up the master sync object or bpm, but those should be clearly labeled. Whipping this into shape such that it's usable in a production environment is actually not the inconceivable. I've never worked with midi timing so someone who has experience may be able to get there faster. Owen ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Get Mixxx, the #1 Free MP3 DJ Mixing software Today http://mixxx.org Mixxx-devel mailing list Mixxx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mixxx-devel
