AAF read adapter should look for type Clip when it's finding a Marker's parent element from the Track

[jchen9]

In merge request https://github.com/PixarAnimationStudios/OpenTimelineIO/pull/1239, it left markers with the Track if target_track.child_at_time(marker.marked_range.start_time) returns something that does not have markers property, for example Transition.

This is less-than ideal. Instead, it should probably look for Clip and attach the marker to the clip found.

[reinecke]

From the TSC Meeting: Do we want to add some API so child_at_time can filter down so we avoid returning transitions? Do we ever want a transition returned by this method?

[jminor]

Yes, I think that is a good idea. The work-around #1239 has been merged for now, but your suggestion would be a cleaner fix. Does it even make sense for child_at_time to ever return a Transition? Shouldn't a Transition always overlap a different child of the parent Composition?