Extract valid transcodes to reusable function

wagtailvideos/models.py

@@ -184,6 +184,9 @@ class AbstractVideo(CollectionMember, index.Indexed, models.Model):
     def get_track_listing_model(cls):
         return cls.track_listing.related.related_model
     
+    def get_current_transcodes(self):
+        return self.transcodes.exclude(processing=True).filter(error_message__exact='')
+
     def video_tag(self, attrs=None):
         if attrs is None:
             attrs = {}
@@ -192,7 +195,7 @@ class AbstractVideo(CollectionMember, index.Indexed, models.Model):
         if self.thumbnail:
             attrs['poster'] = self.thumbnail.url
 
-        transcodes = self.transcodes.exclude(processing=True).filter(error_message__exact='')
+        transcodes = self.get_current_transcodes()
         sources = []
         for transcode in transcodes:
             sources.append("<source src='{0}' type='video/{1}' >".format(transcode.url, transcode.media_format.name))