Add marker to timeline when we can't find valid track (#41)

Signed-off-by: Austin Witherspoon <[email protected]>

src/otio_aaf_adapter/adapters/advanced_authoring_format.py

@@ -1255,33 +1255,21 @@ def _attach_markers(collection):
                 slot_id = metadata.get("AttachedSlotID")
                 track_number = metadata.get("AttachedPhysicalTrackNumber")
                 target_track = tracks_map.get((slot_id, track_number))
-                if target_track is None:
-                    raise AAFAdapterError(
-                        "Marker '{}' cannot be attached to an item. SlotID: '{}', "
-                        "PhysicalTrackNumber: '{}'".format(
-                            marker.name, slot_id, track_number
-                        )
-                    )
 
                 # remove marker from current parent track
                 current_track.markers.remove(marker)
 
                 # determine new item to attach the marker to
-                try:
-                    target_item = _find_child_at_time(
-                        target_track, marker.marked_range.start_time)
-
-                    if target_item is None or not hasattr(target_item, 'markers'):
-                        # Item found cannot have markers, for example Transition.
-                        # See also `marker-over-transition.aaf` in test data.
-                        #
-                        # Leave markers on the track for now.
-                        _transcribe_log(
-                            'Skip target_item `{}` cannot have markers'.format(
-                                target_item,
-                            ),
-                        )
-                        target_item = target_track
+                if target_track is None:
+                    # This can happen if you export from Avid with "Use Selected Tracks"
+                    # where markers will not point at the correct PhysicalTrackNumber!
+                    _transcribe_log(
+                        f"Cannot find target track for marker: {marker}. "
+                        "Adding to timeline."
+                    )
+                    # Lets add it directly to the timeline "stack" the same way
+                    # OTIO files generated by DaVinci Resolve does.
+                    target_item = timeline.tracks
 
                     # transform marked range into new item range
                     marked_start_local = current_track.transformed_time(
@@ -1290,25 +1278,52 @@ def _attach_markers(collection):
 
                     marker.marked_range = otio.opentime.TimeRange(
                         start_time=marked_start_local,
-                        duration=marker.marked_range.duration
+                        duration=marker.marked_range.duration,
                     )
 
-                except otio.exceptions.CannotComputeAvailableRangeError as e:
-                    # For audio media AAF file (marker-over-audio.aaf),
-                    # this exception would be triggered in:
-                    # `target_item = target_track.child_at_time()` with error
-                    # message:
-                    # "No available_range set on media reference on clip".
-                    #
-                    # Leave markers on the track for now.
-                    _transcribe_log(
-                        'Cannot compute availableRange from {} to {}: {}'.format(
-                            marker,
-                            target_track,
-                            e,
-                        ),
-                    )
-                    target_item = target_track
+                else:
+                    try:
+                        target_item = _find_child_at_time(
+                            target_track, marker.marked_range.start_time)
+
+                        if target_item is None or not hasattr(target_item, 'markers'):
+                            # Item found cannot have markers, for example Transition.
+                            # See also `marker-over-transition.aaf` in test data.
+                            #
+                            # Leave markers on the track for now.
+                            _transcribe_log(
+                                'Skip target_item `{}` cannot have markers'.format(
+                                    target_item,
+                                ),
+                            )
+                            target_item = target_track
+
+                        # transform marked range into new item range
+                        marked_start_local = current_track.transformed_time(
+                            marker.marked_range.start_time, target_item
+                        )
+
+                        marker.marked_range = otio.opentime.TimeRange(
+                            start_time=marked_start_local,
+                            duration=marker.marked_range.duration
+                        )
+
+                    except otio.exceptions.CannotComputeAvailableRangeError as e:
+                        # For audio media AAF file (marker-over-audio.aaf),
+                        # this exception would be triggered in:
+                        # `target_item = target_track.child_at_time()` with error
+                        # message:
+                        # "No available_range set on media reference on clip".
+                        #
+                        # Leave markers on the track for now.
+                        _transcribe_log(
+                            'Cannot compute availableRange from {} to {}: {}'.format(
+                                marker,
+                                target_track,
+                                e,
+                            ),
+                        )
+                        target_item = target_track
 
                 # attach marker to target item
                 target_item.markers.append(marker)

tests/test_aaf_adapter.py

@@ -215,6 +215,10 @@
     "avid_data_track_example.aaf"
 )
 
+BAD_TRACK_NUMBER_ON_MARKER_PATH = os.path.join(
+    SAMPLE_DATA_DIR,
+    "bad_marker_track_from_avid.aaf"
+)
 
 try:
     lib_path = os.environ.get("OTIO_AAF_PYTHON_LIB")
@@ -1230,6 +1234,30 @@ def test_aaf_marker_over_audio_file(self):
             self.assertEqual(label, expected_marker.get('label'))
             self.assertEqual(start_time, expected_marker.get('start_time'))
 
+    def test_aaf_marker_with_bad_track(self):
+        """
+        If you export from Avid with "Use Selected Tracks" selected, Avid
+        will rewrite the track numbers after omitted unselected tracks.
+        The markers, however, may not be updated by avid to reflect the
+        new track numbers!
+        This test confirms that we don't crash when reading such a file.
+        """
+
+        timeline = None
+
+        try:
+            timeline = otio.adapters.read_from_file(
+                BAD_TRACK_NUMBER_ON_MARKER_PATH
+            )
+
+        except Exception as e:
+            print('[ERROR] Transcribing test sample data `{}` caused an exception: {}'.format(  # noqa
+                os.path.basename(BAD_TRACK_NUMBER_ON_MARKER_PATH),
+                e)
+            )
+
+        self.assertIsNotNone(timeline)
+
     def _verify_user_comments(self, aaf_metadata, expected_md):
 
         self.assertTrue(aaf_metadata is not None)