Ticket #40921: 40921.diff

wp-includes/media.php

@@ -2161 +2161 @@
          * @param array $extensions An array of support audio formats. Defaults are
          *                          'mp3', 'ogg', 'm4a', 'wav'.
          */
-        return apply_filters( 'wp_audio_extensions', array( 'mp3', 'ogg', 'm4a', 'wav' ) );
+        return apply_filters( 'wp_audio_extensions', array( 'mp3', 'mp4', 'ogg', 'm4a', 'wav' ) );
 }
 
 /**