We help IT Professionals succeed at work.

We've partnered with Certified Experts, Carl Webster and Richard Faulkner, to bring you two Citrix podcasts. Learn about 2020 trends and get answers to your biggest Citrix questions!Listen Now

x

Control MIDI in VB...

pigeon081297
pigeon081297 asked
on
Medium Priority
900 Views
Last Modified: 2012-06-27
Dear all,

  I'd like to know how can I write a program in VB to control the MIDI. The meaning of controlling the MIDI includes playing a particular note using a particular instrument.

  And I wonder if I need to use API calls...

  Thanks a lot !

Pigeon.
Comment
Watch Question

Commented:
These will be useful...

Declare Function midiOutOpen Lib "winmm.dll" (HMidi As Long, ByVal uDeviceID As Long, ByVal dwCallback As Long, ByVal dwInstance As Long, ByVal dwFlags As Long) As Long
Declare Function midiOutShortMsg Lib "winmm.dll" (ByVal HMidi As Long, ByVal dwMsg As Long) As Long
Declare Function midiOutClose Lib "winmm.dll" (ByVal HMidi As Long) As Long

Then...
Something like...

(inside your initialisation code...)

  '  Open the MIDI Mapper Device 0
  OK = midiOutOpen(HMidi, MIDI_MAPPER, 0, 0, 0)

  '  Check for an error in opening the device
  If OK <> 0 Then
      MsgBox "The MIDI device could not be opened (" & OK & ")"
  End If


(This was used for a specific application, so you will need to fiddle with the bits you send out - depending on the device youa are talking to)

Private Sub SendMIDI(value As Integer)

Const MIDI_CHANNEL = 0
Const CONTROL_GROUP = 85

Dim Throw As Long
Static message As Long

  message = (value * &H10000) + (CONTROL_GROUP * &H100&) + &HB0 + MIDI_CHANNEL
  Throw = midiOutShortMsg(HMidi, message)

  ' - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
Const VELOCITY = 127
 
  message = (VELOCITY * &H10000) + (value * &H100&) + &H90 + MIDI_CHANNEL
  Throw = midiOutShortMsg(HMidi, message)

End Sub

(and finally...)

  Dim OK As Long
 
  '  Close the MIDI Device
  OK = midiOutClose(HMidi)
  '  Check for an error in opening the device
  If OK <> 0 Then
      MsgBox "The MIDI device could not be closed (" & OK & ")"
  End If


Good luck...
MC

Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts

Author

Commented:
Well, I've got your idea, and I've tried your code.

I think it has successfully open the MIDI port, but I'm not sure how can I play a particular note using a particular instrument. Can you give me an example, say playing the Middle C using the Grand Piano ?

And also, when I tried to close the MIDI port using your code, it said it can't. The code is 5, and then I can't open the MIDI port anymore, with error code 4...


Author

Commented:
BTW, what should be the value of HMidi ? How can I know the address of an HMIDIOUT handle ?


Author

Commented:
Ok, I've fixed the problem of opening and closing the port. Now I don't have any error message in during the opening and closing. But still I can't figure out how can I play a note...

Commented:
Hi again...

This routine was written to control a M-O Disk recorder playing audio effects into a TV show.  The specifics of the message have been hard coded for that device.

First item to note is tht HMidi should be global to all the functions.  the 'open' call will set that global valuem and the other calls will reference it.

Second is that you only need ONE of the  midiOutShortMsg() calls to play a note.  the values (&H90 and &HB0) were offsets into a command table of the M-O box.

To select the voice that you want to use will require that you read up a bit more onm the MIDI-MAPPER, and the MIDI-CHANNEL numbers that you are using.

The original base for my code came from "Visual Basic 4 - API "How-To"" from Waite Group Press.  A very useful book.

Regards
MC

Author

Commented:
Good... but really I need an example, can you make one for me ? Really thanks.

One more thing, is the VELOCITY the frequency of the note ? Or what is that ? And I've inserted the MIDI_MAPPER constant from the API viewer, should I do this ?

Thanks a lot !

Commented:
VELOCITY is normally assigned to the volume of the note played.  the 'value' field that I pass is the 'note'.

Send me your email address, and I can send you a whole VBP/FRM/BAS set to demo the goodies.

Regards
mcoop@pop.jaring.my
Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.