Writer: added support for mob attribute list

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

src/otio_aaf_adapter/adapters/aaf_adapter/aaf_writer.py

@@ -114,6 +114,7 @@ def __init__(self, input_otio, aaf_file, **kwargs):
 
         # transcribe timeline comments onto composition mob
         self._transcribe_user_comments(input_otio, self.compositionmob)
+        self._transcribe_mob_attributes(input_otio, self.compositionmob)
 
     def _unique_mastermob(self, otio_clip):
         """Get a unique mastermob, identified by clip metadata mob id."""
@@ -126,12 +127,14 @@ def _unique_mastermob(self, otio_clip):
             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 clip comments / mob attributes onto master mob
+            self._transcribe_user_comments(otio_clip.media_reference, mastermob)
+            self._transcribe_mob_attributes(otio_clip, mastermob)
 
-            # transcribe media reference comments onto master mob.
-            # this might overwrite clip comments.
+            # transcribe media reference comments / mob attributes onto master mob.
+            # this might overwrite clip comments / attributes.
             self._transcribe_user_comments(otio_clip.media_reference, mastermob)
+            self._transcribe_mob_attributes(otio_clip.media_reference, mastermob)
 
         return mastermob
 
@@ -226,6 +229,22 @@ def _transcribe_user_comments(self, otio_item, target_mob):
                     f"'{type(val)}' for key '{key}'."
                 )
 
+    def _transcribe_mob_attributes(self, otio_item, target_mob):
+        """Transcribes mob attribute list onto the `target_mob`.
+        This can be used to roundtrip specific mob config values, like audio channel
+        settings.
+        """
+        mob_attr_map = otio_item.metadata.get("AAF", {}).get("MobAttributeList", {})
+        mob_attr_list = aaf2.misc.TaggedValueHelper(target_mob['MobAttributeList'])
+        for key, val in mob_attr_map.items():
+            if isinstance(val, (int, str)):
+                mob_attr_list[key] = val
+            elif isinstance(val, (float, Rational)):
+                mob_attr_list[key] = aaf2.rational.AAFRational(val)
+            else:
+                raise ValueError(f"Unsupported mob attribute type '{type(val)}' for "
+                                 f"key '{key}'.")
+
 
 def validate_metadata(timeline):
     """Print a check of necessary metadata requirements for an otio timeline."""