Re: MIDI Sysex and more
Re: MIDI Sysex and more
- Subject: Re: MIDI Sysex and more
- From: Kurt Revis <email@hidden>
- Date: Fri, 15 Feb 2002 04:37:34 -0800
On Friday, February 15, 2002, at 03:09 AM, Jakob Cederlund wrote:
I'm sorry if this has already been on the list. (Is there a nice app
for reading archives? The webinterface is bit raw...)
Supposedly the mailing list administrators are working on a new archive
system, to go live in the near future.
- MIDISendSysex can't handle more than 3 bytes at a time. You can use
a completion proc to send larger packets. You have to make sure that
you end on a sysex-end, however. If not, CoreMIDI hangs the system for
a couple of seconds, and nothing is delivered to your MIDI device.
This is a bug in the MIDIMAN driver. It works correctly with other
devices--I have a MOTU 2x2 interface which sends sysex just fine. Bruno
Di Gleria posted a workaround on January 4th (subject: Re: More MIDI
sysex problems). Note that you will have similar problems if you try to
send the same sysex through MIDISend() directly (I summarized this on
the list the next day).
- MIDIPortDispose hangs forever if you call it before MIDISendSysex
has finished (which is only notified through the completion proc,
AFAIK).
I haven't tried this myself. If you can, put together a test program and
file a bug--this is the best way to get Apple to fix things.
- Occasionally, MIDIGetNumberOfSources etc. hangs, and you must kill
the MIDIServer process (e.g. by using "kill" from the terminal).
The hanging MIDIServer is probably the result of some other bug, or the
bad MIDIMAN driver. Or, you might be trying to send a packet list which
is greater than 1024 bytes, which will potentially hang or crash the
MIDIServer. (This has supposedly been fixed for a future release.)
Also it seems that sending MIDI slows down my app quite a bit. (Checked
it out using Sampler, great tool!)
Well, I've seen times when the MIDIServer process and/or the kernel will
start using lots of CPU for no apparent reason--this will also
potentially slow down other processes on the machine. This may or may
not be related to your problem--how much is "quite a bit"? (I haven't
done any particular profiling of sending MIDI yet...)
--
Kurt Revis
email@hidden
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