fix tempo handling of multitrack MIDI files; fixes #218

CPJKU · Oct 3, 2016 · aea4451 · aea4451
1 parent 184bdcf
commit aea4451
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Showing 5 changed files with 26 additions and 3 deletions.
diff --git a/CHANGES.rst b/CHANGES.rst
@@ -4,6 +4,10 @@ Release Notes
 Version 0.15.dev0
 -----------------
 
+Other changes:
+
+* Fix tempo handling of multi-track MIDI files (#219)
+
 Version 0.14.1 (release date: 2016-08-01)
 -----------------------------------------
 

diff --git a/madmom/utils/midi.py b/madmom/utils/midi.py
@@ -1488,14 +1488,16 @@ def tempi(self, suppress_warnings=False):
             warnings.warn('this method will be removed soon, do not rely on '
                           'its output, rather fix issue #192 ;)')
         # create an empty tempo list
+        tempo_events = []
         for i, track in enumerate(self.tracks):
             # get a list with tempo events
-            tempo_events = [e for e in track.events if
-                            isinstance(e, SetTempoEvent)]
+            track_tempo_events = [e for e in track.events if
+                                  isinstance(e, SetTempoEvent)]
             # tempo events should be only in the first track of a MIDI file
-            if tempo_events and i > 0:
+            if track_tempo_events and i > 0:
                 raise ValueError('SetTempoEvents should be only in the first '
                                  'track of a MIDI file.')
+            tempo_events.extend(track_tempo_events)
 
         # convert to desired format (tick, microseconds per tick)
         tempi = [(e.tick, e.microseconds_per_quarter_note /

diff --git a/tests/data/annotations/multitrack.mid b/tests/data/annotations/multitrack.mid
diff --git a/tests/test_utils.py b/tests/test_utils.py
@@ -51,6 +51,7 @@
                     pj(ANNOTATIONS_PATH, 'stereo_sample.notes'),
                     pj(ANNOTATIONS_PATH, 'stereo_sample.notes.mirex'),
                     pj(ANNOTATIONS_PATH, 'stereo_sample.sv'),
+                    pj(ANNOTATIONS_PATH, 'multitrack.mid'),
                     pj(ANNOTATIONS_PATH, 'piano_sample.mid'),
                     pj(ANNOTATIONS_PATH, 'piano_sample.notes_in_beats')]
 

diff --git a/tests/test_utils_midi.py b/tests/test_utils_midi.py
@@ -87,6 +87,22 @@ def test_notes_in_beats(self):
         notes_ = midi.notes(unit='b')[:, :4]
         self.assertTrue(np.allclose(notes, notes_))
 
+    def test_multitrack(self):
+        # read a multi-track MIDI file
+        midi = MIDIFile.from_file(pj(ANNOTATIONS_PATH, 'multitrack.mid'))
+        notes = midi.notes(unit='b')
+        self.assertTrue(np.allclose(notes[:4], [[0, 60, 0.5, 90, 2],
+                                                [0, 72, 2, 90, 1],
+                                                [0.5, 67, 0.5, 90, 2],
+                                                [1, 64, 0.5, 90, 2]],
+                                    atol=1e-2))
+        notes = midi.notes(unit='s')
+        self.assertTrue(np.allclose(notes[:4],
+                                    [[0, 60, 0.2272725, 90, 2],
+                                     [0, 72, 0.90814303, 90, 1],
+                                     [0.2272725, 67, 0.22632553, 90, 2],
+                                     [0.45359803, 64, 0.22821947, 90, 2]]))
+
 
 # clean up
 def teardown():