add wildcard branches for matches on enums

src/util/media.rs

@@ -22,6 +22,8 @@ impl From<AVMediaType> for Type {
             AVMEDIA_TYPE_SUBTITLE => Type::Subtitle,
             AVMEDIA_TYPE_ATTACHMENT => Type::Attachment,
             AVMEDIA_TYPE_NB => Type::Unknown,
+
+            _ => unimplemented!(),
         }
     }
 }