if len(req_format_split) > 1:
                     req_ext, req_quality = req_format_split
                     for allowed_quality in ALLOWED_QUALITIES:
                         if req_ext == allowed_quality.ext and req_quality in allowed_quality.qualities:
                             return (AllowedQuality(req_ext, (req_quality, )), )
                 req_ext = 'webm' if self._downloader.params.get('prefer_free_formats') else 'mp4'
                 if len(req_format_split) > 1:
                     req_ext, req_quality = req_format_split
                     for allowed_quality in ALLOWED_QUALITIES:
                         if req_ext == allowed_quality.ext and req_quality in allowed_quality.qualities:
                             return (AllowedQuality(req_ext, (req_quality, )), )
                 req_ext = 'webm' if self._downloader.params.get('prefer_free_formats') else 'mp4'