from MidiOutFile import MidiOutFile

from MidiInFile import MidiInFile



"""

This is an example of the smallest possible type 0 midi file, where 

all the midi events are in the same track.

"""





class Transposer(MidiOutFile):

    

    "Transposes all notes by 1 octave"

    

    def _transp(self, ch, note):

        if ch != 9: # not the drums!

            note += 12

            if note > 127:

                note = 127

        return note





    def note_on(self, channel=0, note=0x40, velocity=0x40):

        note = self._transp(channel, note)

        MidiOutFile.note_on(self, channel, note, velocity)

        

        

    def note_off(self, channel=0, note=0x40, velocity=0x40):

        note = self._transp(channel, note)

        MidiOutFile.note_off(self, channel, note, velocity)





out_file = 'midiout/transposed.mid'

midi_out = Transposer(out_file)



#in_file = 'midiout/minimal_type0.mid'

#in_file = 'test/midifiles/Lola.mid'

in_file = 'test/midifiles/tennessee_waltz.mid'

midi_in = MidiInFile(midi_out, in_file)

midi_in.read()