Remove erronous unsupported file formats from tagger

picard/file.py

@@ -108,6 +108,12 @@ class File(QtCore.QObject, Item):
         if error is not None:
             self.error = str(error)
             self.state = self.ERROR
+            from picard.formats import supported_extensions
+            file_name, file_extension = os.path.splitext(self.base_filename)
+            if file_extension not in supported_extensions():
+                self.remove()
+                log.error('Unsupported media file {} wrongly loaded. Removing ...'.format(self))
+                return
         else:
             self.error = None
             self.state = self.NORMAL

picard/formats/mp4.py

@@ -118,14 +118,6 @@ class MP4File(File):
             file.add_tags()
 
         metadata = Metadata()
-        if not tags:
-            # MPEG-4 file in an mov container is unsupported and is one of
-            # the formats which returns a positive score in guess_format method
-            # If we are unable to add tags, it is not a supported mp4 file
-            # remove it and log an error
-            log.error("Unable to load tags for file {}".format(self))
-            self.remove()
-            return metadata
 
         for name, values in tags.items():
             if name in self.__text_tags: