19 Feb
2010
19 Feb
'10
11:17 p.m.
Hi wolke!
On Sat, 20 Feb 2010, m.wolkstein(a)gmx.de wrote:
for more information's read here.
http://en.wikipedia.org/wiki/MIDI_beat_clock
my question, exist something like this for alas. i am interested to send midi beat clock
signals from hydrogen to external hardware synthesisers/arpeggiators. and i am explicit
not interested to sync them to any timecode. because the external machines have to run
independent and in a randomly order. they only have to sync there beats.
I wrote a program to do this. It slaves to the JACK
transport and sends out MIDI clock pulses accordingly. You
can check it out here:
http://www.teuton.org/~gabriel/jack_midi_clock/
I've used this to record with Ardour and a Korg MS2000R.
The MS2000R is able to sync arpeggiators and LFO's to MIDI
clock pulses. It ignores start/stop/continue messages.
However, jack_midi_clock still implements those. It does
/not/ implement MIDI Tick (but it could...).
and about ticks.
i fond out that linux audio apps all have other or there own definitions about the
quantity of ticks per beat.
make it sense to find out an accordance about ticks per beat. or is this irrelevant for
any syncing. especially i mean here syncing via jack-transport.
As PD said, the MIDI spec requires That MIDI Clock (0xF8)
pulses be sent out at a rate of 24 clocks per quarter note.
Meanwhile, a MIDI Tick (0xF9) is sent out at a rate of 1
tick per 10 ms. The difference is whether you are syncing
time or tempo. Sounds like you want tempo (MIDI Clock
0xF8).
There's a pretty good MIDI reference here:
http://www.blitter.com/~russtopia/MIDI/~jglatt/tech/midispec.htm
http://www.blitter.com/~russtopia/MIDI/~jglatt/
FWIW, using MIDI clock you can effectively sync tempo.
Synchronizing down-beats is more difficult... since there is
never a signal that says "this clock pulse marks a beat."
Hope this helps!
-gabriel