Source Code for Module echonest.remix.support.midi.example_transpose_octave

 1  from MidiOutFile import MidiOutFile 
 2  from MidiInFile import MidiInFile 
 3  
 
 4  """
 
 5  This is an example of the smallest possible type 0 midi file, where 
 
 6  all the midi events are in the same track.
 
 7  """ 
 8  
 
 9  
 
10 -class Transposer(MidiOutFile): 
11      
 
12      "Transposes all notes by 1 octave" 
13      
 
14 -    def _transp(self, ch, note): 
15          if ch != 9: # not the drums! 
16              note += 12 
17              if note > 127: 
18                  note = 127 
19          return note 
20  
 
21  
 
22 -    def note_on(self, channel=0, note=0x40, velocity=0x40): 
23          note = self._transp(channel, note) 
24          MidiOutFile.note_on(self, channel, note, velocity) 
25          
 
26          
 
27 -    def note_off(self, channel=0, note=0x40, velocity=0x40): 
28          note = self._transp(channel, note) 
29          MidiOutFile.note_off(self, channel, note, velocity) 
30  
 
31  
 
32  out_file = 'midiout/transposed.mid' 
33  midi_out = Transposer(out_file) 
34  
 
35  #in_file = 'midiout/minimal_type0.mid'
 
36  #in_file = 'test/midifiles/Lola.mid'
 
37  in_file = 'test/midifiles/tennessee_waltz.mid' 
38  midi_in = MidiInFile(midi_out, in_file) 
39  midi_in.read() 
40