How should my program collect MIDI messages?

October 13, 2007 6:11 PM

Where can I find enough info on Windows' MIDI API to start using it?

I have a Behringer controller with a "USB MIDI" interface (a USB cable goes straight from the box to the computer). I want to catch the messages sent from this unit in a Matlab program. There should be built-in support for this in Windows, but I don't find much documentation about it. Can someone please explain to me what DLL or ActiveX element to load, how to create a session, what functions to call and all the other details needed to see some MIDI messages on the screen?

posted by springload to Computers & Internet (8 answers total)

If you want to access the MIDI API directly, the MSDN documentation is probably the best place to start. It looks like most of the functions you'll need are in winmm.dll.

I don't know how easy that will be to interface with Matlab, though; does it even support event-driven programming?
posted by teraflop at 6:38 PM on October 13, 2007

Response by poster: teraflop: With the basic DLL support, a native Matlab callback would likely be at least very hard to implement. The easiest thing for me would be a dll function that returns with the message as soon as it has arrived. Any recommendations for a wrapper that can do something like this?
posted by springload at 4:21 AM on October 14, 2007

Do you need to do this in realtime? If not, you could use any freeware midi-recording software to capture a .mid file. Then you can either parse the file in Matlab, or use a utility like MIDICSV or MIDI-Perl to convert the data to something easier for Matlab to read.
posted by moonmilk at 7:07 AM on October 14, 2007

A quick googling for matlab midi brough up the Matlab Midi Toolbox .. might be worth looking into.

I'm not too familiar with matlab and what it supports, but C#/.NET is probably the easiest way to get started. seems fairly robust.

If you are ever working with MIDI, jglatt's resource center should be your #1 bookmark.
posted by cmicali at 7:08 AM on October 14, 2007

Response by poster: moonmilk: Unfortunately, this has to be done in realtime, message by message.

cmicali: I've snoped around jglatt's site, and it contains some nice information. .NET components can be accessed from Matlab, though I'm not sure how to go about it. A solution like that is one option, accessing winmm.dll from a MEX file (Matlab's C interface) is another one. Again, details and alternatives are most welcome - I'm very inexperienced with API interfacing.
posted by springload at 8:13 AM on October 14, 2007

Response by poster: Another possibility: Matlab can quite easily use Java classes. JavaSound seems to have useful MIDI functions, but I don't know where to find it. I tried to install a recent Java SDK, but I still can't find it. Should I look for a jar file with a different name?
posted by springload at 2:32 PM on October 14, 2007

I wrote some code 8 years ago to made the MIDI APIs available to Java on the PC. If you want, I'll dig out the source code for you. I never did any code for input, but if I recall correctly, the input routines are in the same family/region as the output routines.
posted by plinth at 6:32 AM on October 15, 2007

Response by poster: For the record: I ended up using the COM interface of MIXI-OX. Thanks for the advice, everybody.
posted by springload at 2:31 PM on October 16, 2007