AAFWriter: added support for AAF user comments (OpenTimelineIO#22)

Signed-off-by: Tim Lehr <[email protected]>

src/otio_aaf_adapter/adapters/aaf_adapter/aaf_writer.py

@@ -5,6 +5,7 @@
 
 Specifies how to transcribe an OpenTimelineIO file into an AAF file.
 """
+from numbers import Rational
 
 import aaf2
 import abc
@@ -87,6 +88,9 @@ def __init__(self, input_otio, aaf_file, **kwargs):
         self._unique_tapemobs = {}
         self._clip_mob_ids_map = _gather_clip_mob_ids(input_otio, **kwargs)
 
+        # transcribe timeline comments onto composition mob
+        self._transcribe_user_comments(input_otio, self.compositionmob)
+
     def _unique_mastermob(self, otio_clip):
         """Get a unique mastermob, identified by clip metadata mob id."""
         mob_id = self._clip_mob_ids_map.get(otio_clip)
@@ -97,6 +101,14 @@ def _unique_mastermob(self, otio_clip):
             mastermob.mob_id = aaf2.mobid.MobID(mob_id)
             self.aaf_file.content.mobs.append(mastermob)
             self._unique_mastermobs[mob_id] = mastermob
+
+            # transcribe clip comments onto master mob
+            self._transcribe_user_comments(otio_clip, mastermob)
+
+            # transcribe media reference comments onto master mob.
+            # this might overwrite clip comments.
+            self._transcribe_user_comments(otio_clip.media_reference, mastermob)
+
         return mastermob
 
     def _unique_tapemob(self, otio_clip):
@@ -140,6 +152,19 @@ def track_transcriber(self, otio_track):
                 f"Unsupported track kind: {otio_track.kind}")
         return transcriber
 
+    def _transcribe_user_comments(self, otio_item, target_mob):
+        """Transcribes user comments on `otio_item` onto `target_mob` in AAF."""
+
+        user_comments = otio_item.metadata.get("AAF", {}).get("UserComments", {})
+        for key, val in user_comments.items():
+            if isinstance(val, int):
+                target_mob.comments[key] = val
+            elif isinstance(val, (float, Rational)):
+                target_mob.comments[key] = aaf2.rational.AAFRational(val)
+            else:
+                # ensure we can store comment value by converting it to unicode string
+                target_mob.comments[key] = str(val)
+
 
 def validate_metadata(timeline):
     """Print a check of necessary metadata requirements for an otio timeline."""

tests/test_aaf_adapter.py

@@ -1679,6 +1679,46 @@ def test_generator_reference(self):
             cl.media_reference.generator_kind = "not slug"
             otio.adapters.write_to_file(tl, tmp_aaf_path)
 
+    def test_aaf_writer_user_comments(self):
+        # construct simple timeline
+        timeline = otio.schema.Timeline()
+        range = otio.opentime.TimeRange(
+            otio.opentime.RationalTime(0, 24),
+            otio.opentime.RationalTime(100, 24),
+        )
+        media_ref = otio.schema.ExternalReference(available_range=range)
+        clip = otio.schema.Clip(source_range=range)
+        clip.media_reference = media_ref
+        timeline.tracks.append(otio.schema.Track(children=[clip]))
+
+        # add comments to clip + timeline
+        original_comments = {
+            "Test_String": "Test_Value",
+            "Test_Int": 1337,
+            "Test_Float": 13.37,
+            "Test_Bool": True,
+        }
+
+        expected_comments = {
+            "Test_String": "Test_Value",
+            "Test_Int": "1337",
+            "Test_Float": aaf2.rational.AAFRational(13.37),
+            "Test_Bool": "True",
+        }
+
+        timeline.metadata["AAF"] = {"UserComments": original_comments}
+        media_ref.metadata["AAF"] = {"UserComments": original_comments}
+
+        _, tmp_aaf_path = tempfile.mkstemp(suffix='.aaf')
+        otio.adapters.write_to_file(timeline, tmp_aaf_path, use_empty_mob_ids=True)
+
+        with aaf2.open(tmp_aaf_path) as aaf_file:
+            print(dict(next(aaf_file.content.mastermobs()).comments.items()))
+            master_mob = next(aaf_file.content.mastermobs())
+            comp_mob = next(aaf_file.content.compositionmobs())
+            self.assertEqual(dict(master_mob.comments.items()), expected_comments)
+            self.assertEqual(dict(comp_mob).comments.items(), expected_comments)
+
     def _verify_aaf(self, aaf_path):
         otio_timeline = otio.adapters.read_from_file(aaf_path, simplify=True)
         fd, tmp_aaf_path = tempfile.mkstemp(suffix='.aaf')