I'm using pygame.midi library to send MIDI Messages (Control Change messages, not notes). The idea is to send from the output (from this python program) to the input of another program.
>>> import time
>>> import pygame.midi as midi
>>> midiout = midi.Output(3)
>>> midi.init()
>>> midiout = midi.Output(3)
>>> midiout.write_short(0x74,124,0)
PortMidi call failed...
PortMidi: `Invalid MIDI message Data'
type ENTER...
As you can see, i'm sending 0x74,124,0. I'm taking those numbers from rakarrack (the application that i want to control) implementation chart: http://rakarrack.sourceforge.net/midiic.html
What am I doing wrong?
MIDI status bytes (the first byte of the message) must have the high (0x80) bit set. the linked chart is a bit confusing, but I'm guessing 0x74 is a data byte and must be preceded by the proper status byte.
>>> import pygame.midi as midi
>>> midi.init()
>>> midiout = midi.Output(0)
>>> midiout.write_short(0xb0, 0x74, 124)
some basic MIDI documentation: http://www.midi.org/techspecs/midimessages.php
control change is 0xbn, where n is the channel number, so 0xb0 is a control change message for channel 0.