This is admittedly lame.

Author: vade

Sources/OpenTimelineIO-AVFoundation/OpenTimelineIO-Extensions/ExternalReference.swift

@@ -95,6 +95,19 @@ extension ExternalReference
             supported = true
         case "mov":
             supported = true
+        case "m4v":
+            supported = true
+           
+            
+        case "m4a":
+            supported = true
+        case "mp3":
+            supported = true
+        case "aiff":
+            supported = true
+        case "wav":
+            supported = true
+
 
         default:
             supported = false