Low-level MIDI input using Visual Basic
=======================================

 What it is
 ----------

 An example of ways in which the low-level MIDI API can be used with 
 Visual Basic. It was written for a MIDI patch editor (still under 
 development). At the top level it provides simple MidiGet(), 
 MidiSysexGet(), and MidiPut() functions for sending and receiving
 MIDI data.
 
 It was designed to be reusable for multiple applications without code
 changes. It is not optimized for speed at all, and is quite slow on
 a 486/66. You could get more speed by using the low-level functions
 directly.
 
 This documentation is obviously very skimpy but there are lots of 
 comments in the code.

 This is my first Visual Basic program and it's far from perfect. Please 
 send constructive criticism and any code improvements to the email 
 addresses below.


 Files
 -----

 Midi library:
 MIDI.BAS          Data structure and constant definitions, routines used
                   by both input and output
 MIDIIN.BAS        MIDI input routines
 MIDIOUT.BAS       MIDI output routines
 MIDICAP.BAS       MIDI device capability routines
 ALLOC.BAS         Declarations for Windows memory allocation functions

 The MIDI library uses the Windows subclassing control MSGBLAST.VBX 
 developed by Ed Staffin of Microsoft Consulting Services and available 
 from Cix, Compuserve, or ftp.microsoft.com.
 
 Example app: a simple monitor with selectable input and output devices. 
 It can echo input data to output data, and displays the incoming MIDI 
 data in hex.
 
 MIDIDEVC.FRM      MIDI input/output device selection form
 MIDITEST.FRM      Main form for test application
 MIDITEST.BAS      Code for test application
 

 How to use the library
 ======================
 
 MIDI input
 ----------
 
 1. Add MSGBLAST.VBX to your project and put a message blaster control 
 on your form. In the message blaster's Message event code, put:

    Call midiCallbackWndProc(MsgVal, wParam, lParam)
    
 2. Put a label control on your form and set its Visible property to false.
 When some MIDI input is received, this control's Change event will be
 triggered.
 
 3. Call vbMidiInOpen with your main form's window handle (hwnd), the 
 number of the MIDI device you want to open, the message blaster control,
 and the label control. Save the midi input handle returned by
 vbMidiInOpen. See OpenDev in MIDITEST.BAS for an example.
 
 4. Call midiInStart with the midi input handle.
 
 5. In the Change event procedure of the label from step 2, put code to
 deal with MIDI input when it arrives. Call the MidiGet() function to 
 retrieve short MIDI messages, or the MidiSysexGet() function to retrieve
 Sysex data. See midiInputArrived in MIDITEST.BAS for an example.
 
 6. Call vbMidiOutClose when you've finished.

 Note that the timing clock and active sensing MIDI messages are 
 filtered out by some code in midiCallbackWndProc in MIDI.BAS, to 
 improve performance slightly.

 
 MIDI output
 -----------
 
 1. Call vbMidiOutOpen with your main form's window handle and the number
 of the midi device you want to open. Save the returned output handle.
 See OpenDev in MIDITEST.BAS for an example.
 
 2. Send output using either MidiPut (takes string argument, works for 
 short messages and sysex messages), vbMidiOutShortMsg (argument is MIDI
 message bytes encoded in a Long), or vbMidiOutLongMsg (string argument,
 long messages only).
 
 Note that the output functions will loop until output is complete
 (see comments in vbMidiOutLongMsg).
 
 
 MIDI device capabilities
 ------------------------
 See MIDIDEVC.FRM for examples on using these functions.

 
 Contacting me
 -------------
 Please send email to either davec@wsti.demon.co.uk or 
 dchurcher@cix.compulink.co.uk