How can I write a MIDI file with Python?

Question

I am writing a script to convert a picture into MIDI notes based on the RGBA values of the individual pixels. However, I cannot seem to get the last step working, which is to actually output the notes to a file.

I have tried using the MIDIUtil library, however its documentation is not the greatest and I can't seem to figure it out.

If anyone could tell me how to sequence the notes (so that they don't all begin at the beginning) it would be greatly appreciated.

Answer 1

Looking at the sample, something like

from midiutil.MidiFile import MIDIFile

# create your MIDI object
mf = MIDIFile(1)     # only 1 track
track = 0   # the only track

time = 0    # start at the beginning
mf.addTrackName(track, time, "Sample Track")
mf.addTempo(track, time, 120)

# add some notes
channel = 0
volume = 100

pitch = 60           # C4 (middle C)
time = 0             # start on beat 0
duration = 1         # 1 beat long
mf.addNote(track, channel, pitch, time, duration, volume)

pitch = 64           # E4
time = 2             # start on beat 2
duration = 1         # 1 beat long
mf.addNote(track, channel, pitch, time, duration, volume)

pitch = 67           # G4
time = 4             # start on beat 4
duration = 1         # 1 beat long
mf.addNote(track, channel, pitch, time, duration, volume)

# write it to disk
with open("output.mid", 'wb') as outf:
    mf.writeFile(outf)