[Jack-Devel] [jackosx] MIDI timing and Jack (not OS-X-specific)

Writing a synth. 

I started thinking about the way the jack process callback works, wrt midi, and I'm becoming convinced that using Jack isn't the best approach, unless I misunderstand the way it works. 

At the beginning of the process callback, a jack_midi_get_event_count() call is made. Then, as I walk through the frames of the buffer, I compare where I am in the buffer to the next available midi event, and if I'm on the right sample I process the midi. 

But I think this HAS to mean that the actual midi event happened at least one buffer's worth of data ago, right? I can't get a count of midi events at the beginning of the process callback if they haven't happened yet... 

I looked at the source to a2jmidid (ALSA to Jack MIDI bridge for linux) and I noticed it doesn't even bother with the timestamps (I think I've got the most recent source). So ... do people just tend to not worry about a 512 (default I think) sample delay (or the sort of jitter that a2jmidid is causing) in midi processing? 

This leads me to think I will use CoreMIDI to get the midi events and handle the audio the jack way.

Please correct me if I'm wrong,
Eric






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