[LAD] Deciphering jack-smf-utils -- Jack MIDI stuff
ingeniousnebbish at cox.net
Mon Feb 18 14:23:56 UTC 2013
This question arises from jack-keyboard rather than jack-smf-utils. The basic
framework is very similar, but jack-keyboard gets input from a gui rather than
from a smf.
So the idea is that you press a key on the keyboard and an event handler gets
called. The event handler calls queue_new_message(int, int, int), which
creates a midi event ev on the stack. Then it calls queue_message(&ev).
queue_message() copies ev to a ringbuffer. Okay, so far, so good.
queue_new_message() exits and ev goes out of scope, so only the copy on the
The next process cycle process_callback() is invoked. It calls
process_midi_output(), which takes data from the ringbuffer and moves it to
Is this what's happening?
Now for receiving timing info from Jack. Where's a good place to look for code
that explains how to get (and display in a gui widget) the current time while
transport is rolling? There's QJackCtl of course. Is there something simpler,
more of an example program?
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