On Thu, 2010-07-15 at 21:14 +0100, James Morris wrote: > On 15 July 2010 20:27, Nathanael Anderson <[email protected]> wrote: > > > If I don't find anything I want to hack something together, so a primer on > > midi tempo sync, and how to program with it would be appreciated. > > Hi Nathanael, > > I'm using JACK MIDI which makes it quite easy (compared with designing > the program architecture) to output MIDI events. > > I'm also trying to use JACK transport to a) sync with other timebase > master programs, b) to act as a simple timebase master. > > The JACK timebase and transport documentation focuses on using JACK to > accomplish these tasks. > see here: http://jackaudio.org/files/docs/html/transport-design.html > There is also a transport example in the examples directory within the > source code for JACK. > > But these documents do not go into the issues you'll come across when > trying to accurately synchronize your application with another. Or > accurately acting as timebase master (ie you've recorded some audio > sequenced by your MIDI program acting as timebase master but it does > not line up when imported into a DAW with the same tempo/meter). > > Beyond this, you'll have to look into other software source code > (AFAIK). But it's far from trivial. > > Cheers, > James.
Perhaps the source code for Qtractor could help. I've got timing issues, but they have nothing to do with JACK transport. I guess (didn't use it) JACK transport is okay, with the limits Rui mentioned today. Usually Rui does good programming. -------- Forwarded Message -------- From: Rui Nuno Capela <[email protected]> To: Ralf Mardorf <[email protected]> Cc: Robin Gareus <[email protected]>, Devin Anderson <[email protected]>, qtractor-devel <[email protected]>, 64studio-devel <[email protected]>, Linux-Audio-Dev <[email protected]> Subject: Re: [LAD] Transport issue for Qtractor - has impact to the jitter issue Date: Thu, 15 Jul 2010 09:33:53 +0100 On Thu, 15 Jul 2010 10:15:53 +0200, Ralf Mardorf wrote: > Transport issue for Qtractor - has impact to the jitter issue > what transport issue? oh i see... :) qtractor has in fact a known trouble with jack transport sync when slaving to period/buffer sizes greater than 2048 frames. it skids. maybe that's exactly what you're experiencing when running jackd -p4096. i'll recommend for you to turn jack transport mode to "none" or "master" only, never "slave" nor "full" on those situations (in view/options.../audio/jack Transport). another recommendation would be to grab the latest from svn trunk where the said trouble has been already mitigated :) cheers _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
