#youtube_dl/extractor/youtube.py: Signature decryption not NOT invoking js/swf sig parsers
        if player_type == 'js':
            raise ExtractorError("Youtube's DRM has prevented this software from obtaining the video URL", expected=True)
        elif player_type == 'swf':
            raise ExtractorError("Youtube's DRM has prevented this software from obtaining the video URL", expected=True)