MIDI output jam

[Amit]

Hi,

I'm developing a MIDI application, and have been experiencing a constant problem with midi output. I wrote a little MIDI echo utility to try and isolate the problem, but without much luck. The problem is that when playing at high speeds, it seems like the output port doesn't handle the pressure and sometimes freezes for a whole second or even more, before spitting out all the notes that were sent to it.
Now, I tested the same MIDI setup on the same platform with 3 different programs - Cubase SX, Tracktion, and MIDI-OX - and none of them have this problem.

As far as programming environment, I tried 3 options:
1. Using Java with the JavaSound API.
2. Using Java with JavaMidi API (open source library that uses JNI an native implementation of all the MIDI I/O).
3. Using C++ with the JUCE library.

The best result - but still not sufficient - was option 2.

I would appreciate any ideas about this.
Thanks,
Amit

[C00kie]

Hi Amit, welcome to KVR!

Just some thoughts of mine:

There are some excellent midi monitoring programs available, for example Midi-Ox. Although not as much fun ofcourse as building it yourself, it could help you on concentrating on the other program you're writing.

You think that the problem is you're probably overloading the physical port. So avoid doing that Maybe esier said than done... Isn't there a semaphore or something you can check weather the device is ready for the next data? Or keep a timer yourself so you don't feed the data quicker than can be handled?

Also, this post should better be at the DSP Development forum. Maybe a moderator can move it there?

Enjoy!!