midi2bin.py

import midi, sys

pattern = midi.read_midifile(sys.argv[1])

def pitchconv(pitch):
    return int(round(1193180.0 / (2**((pitch-69)/12.0)*440), 0))

with open(sys.argv[2], "wb") as out:
    pitches = [pitchconv(event.pitch) for event in pattern[1] if isinstance(event, midi.NoteOnEvent)]

    b = 0
    d = 0

    t = 0
    o = -1
    for event in pattern[1]:
        if isinstance(event, midi.NoteOnEvent):
            if event.velocity == 0:
                d += int(round(event.tick/48.0, 0))
                p = pitchconv(event.pitch)
                out.write(chr(p & 0xff) + chr(d << 5 | p >> 8))
                b = 0
            else:
                d = int(round(event.tick/48.0, 0))