write_midifile doesn't work under Python 3

[marczellm]

I'm using the Python 3 branch. When writing a MIDI file using write_midifile, it does not work as expected. When I write 10 notes to a track, they don't show up in SONAR. If I write my full 500 notes to it, SONAR doesn't even open the file. Neither does Windows Media Player in either case.

I don't know how to inspect / validate the file, but I've attached it.
output.mid.zip

[vishnubob]

Can you please share the code you used to generate this file?

[marczellm]

Hi,

This does not generate that exact attached file, because it was random generated, but it still generates a file that makes SONAR choke.

import midi


class Note:
    def __init__(self):
        self.tick_abs = 0
        self.tick_rel = 0
        self.duration = 0
        self.pitch = 0
        self.velocity = 0
        self.ticks_since_chord = 0
        self.ticks_since_last_note_start = 0
        self.ticks_since_last_note_end = 0


def main():
    gen = []
    for i in range(10):
        n = Note()
        n.pitch = 80
        n.tick_abs = 800
        n.duration = 800
        gen.append(n)

    kf = midi.Pattern()
    track = midi.Track()
    last_tick = 0
    for n in gen:
        on = midi.NoteOnEvent(tick=n.tick_abs - last_tick, pitch=n.pitch, velocity=100)
        off = midi.NoteOnEvent(tick=n.duration, pitch=n.pitch, velocity=0)
        track.append(on)
        track.append(off)
        last_tick = n.tick_abs + n.duration
    track.append(midi.EndOfTrackEvent(tick=1))
    kf.append(track)
    midi.write_midifile("bad.mid", kf)


if __name__ == "__main__":
    main()