map track language to track

ox/file.py

@@ -215,10 +215,16 @@ def ffprobe(filename):
     info['metadata'] = ffinfo['format'].get('tags', {})
     for s in ffinfo['streams']:
         tags =  s.pop('tags', {})
+        language = None
         for t in tags:
-            info['metadata'][t] = tags[t]
+            if t == 'language':
+                language = tags[t]
+            else:
+                info['metadata'][t] = tags[t]
         if s.get('codec_type') in ('audio', 'video'):
             stream = {}
+            if language and language != 'und':
+                stream['language'] = language
             keys = [ 
                 'codec_name',
                 'width',