Writer: default audio pan to mid, can now be set via metadata

src/otio_aaf_adapter/adapters/aaf_adapter/aaf_writer.py

@@ -762,20 +762,37 @@ def aaf_sourceclip(self, otio_clip):
                                                            "LinearInterp",
                                                            "LinearInterp")
         self.aaf_file.dictionary.register_def(interp_def)
-        # PointList
-        length = int(otio_clip.duration().value)
-        c1 = self.aaf_file.create.ControlPoint()
-        c1["ControlPointSource"].value = 2
-        c1["Time"].value = aaf2.rational.AAFRational(f"0/{length}")
-        c1["Value"].value = 0
-        c2 = self.aaf_file.create.ControlPoint()
-        c2["ControlPointSource"].value = 2
-        c2["Time"].value = aaf2.rational.AAFRational(f"{length - 1}/{length}")
-        c2["Value"].value = 0
+
+        # generate PointList for pan
         varying_value = self.aaf_file.create.VaryingValue()
         varying_value.parameterdef = param_def
         varying_value["Interpolation"].value = interp_def
-        varying_value["PointList"].extend([c1, c2])
+
+        length = int(otio_clip.duration().value)
+
+        # default pan points are mid pan
+        default_points = [
+            {
+                "ControlPointSource": 2,
+                "Time": f"0/{length}",
+                "Value": "1/2",
+            },
+            {
+                "ControlPointSource": 2,
+                "Time": f"{length - 1}/{length}",
+                "Value": "1/2",
+            }
+        ]
+        cp_dict_list = otio_clip.metadata.get("AAF", {}).get("Pan", {}).get(
+            "ControlPoints", default_points)
+
+        for cp_dict in cp_dict_list:
+            point = self.aaf_file.create.ControlPoint()
+            point["Time"].value = aaf2.rational.AAFRational(cp_dict["Time"])
+            point["Value"].value = aaf2.rational.AAFRational(cp_dict["Value"])
+            point["ControlPointSource"].value = cp_dict["ControlPointSource"]
+            varying_value["PointList"].append(point)
+
         opgroup = self.timeline_mobslot.segment
         opgroup.parameters.append(varying_value)
 

tests/test_aaf_adapter.py

@@ -1937,6 +1937,76 @@ def test_aaf_writer_global_start_time(self):
 
             self._verify_aaf(tmp_aaf_path)
 
+    def test_aaf_writer_audio_pan(self):
+        """Test Clip with custom audio pan values"""
+        tl = otio.schema.Timeline()
+
+        # Add an audio clip with pan metadata
+        clip = otio.schema.Clip(
+            name="Panned Audio Clip",
+            metadata={},
+            source_range=otio.opentime.TimeRange(
+                start_time=otio.opentime.RationalTime(0, 24),
+                duration=otio.opentime.RationalTime(100, 24),
+            )
+        )
+        clip.media_reference = otio.schema.MissingReference(
+            available_range=otio.opentime.TimeRange(
+                start_time=otio.opentime.RationalTime(0, 24),
+                duration=otio.opentime.RationalTime(100, 24),
+            ))
+
+        # Add pan metadata
+        clip.metadata["AAF"] = {
+            "Pan": {
+                "ControlPoints": [
+                    {
+                        "ControlPointSource": 2,
+                        "Time": "0",
+                        "Value": "0",
+                    },
+                    {
+                        "ControlPointSource": 2,
+                        "Time": "100",
+                        "Value": "1",
+                    }
+                ]
+            },
+            "SourceID": "urn:smpte:umid:060a2b34.01010101.01010f00."
+                        "13000000.060e2b34.7f7f2a80.5c9e6a3b.ace913a2"
+        }
+
+        tl.tracks.append(
+            otio.schema.Track(children=[clip], kind=otio.schema.TrackKind.Audio)
+        )
+
+        _, tmp_aaf_path = tempfile.mkstemp(suffix='.aaf')
+        otio.adapters.write_to_file(tl, tmp_aaf_path)
+        print(tmp_aaf_path)
+
+        # verify pan values in AAF file
+        with aaf2.open(tmp_aaf_path) as aaf_file:
+            mob = next(aaf_file.content.compositionmobs())
+            slot = mob.slots[0]
+            parameter = list(slot.segment.parameters)[0]
+
+            # extract the pan values
+            param_dicts = [
+                {k: v.value for k, v in dict(p).items()}
+                for p in parameter.pointlist
+            ]
+
+            expected = [
+                {'ControlPointSource': 2,
+                 'Time': aaf2.rational.AAFRational(0, 1),
+                 'Value': aaf2.rational.AAFRational(0, 1)},
+                {'ControlPointSource': 2,
+                 'Time': aaf2.rational.AAFRational(100, 1),
+                 'Value': aaf2.rational.AAFRational(1, 1)}
+            ]
+
+            self.assertEqual(param_dicts, expected)
+
     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')