[soundcloud] 扁平播放列表中的更多元数据

And the produced output {'_type': 'url', 'url': 'https://api.soundcloud.com/tracks/519192720', 'ie_key': 'Soundcloud'} {'_type': 'url', 'url': 'https://api.soundcloud.com/tracks/256094585', 'ie_key': 'Soundcloud'} {'_type': 'url', 'url': 'https://api.soundcloud.com/tracks/172639544', 'ie_key': 'Soundcloud'} {'_type': 'url', 'url': 'https://api.soundcloud.com/tracks/323812800', 'ie_key': 'Soundcloud'} {'_type': 'url', 'url': 'https://api.soundcloud.com/tracks/254961512', 'ie_key': 'Soundcloud'} {'_type': 'url', 'url': 'https://api.soundcloud.com/tracks/1138931146', 'ie_key': 'Soundcloud'} {'_type': 'url', 'url': 'https://api.soundcloud.com/tracks/253133742', 'ie_key': 'Soundcloud'} {'_type': 'url', 'url': 'https://api.soundcloud.com/tracks/309398002', 'ie_key': 'Soundcloud'} {'_type': 'url', 'url': 'https://api.soundcloud.com/tracks/89394347', 'ie_key': 'Soundcloud'} ########################### {'_type': 'url', 'ie_key': 'Youtube', 'id': 'MKYY0IlTMw4', 'url': 'https://www.youtube.com/watch?v=MKYY0IlTMw4', 'title': 'Slowdive - When the Sun Hits (Audio)', 'description': None, 'duration': 290.0, 'view_count': 2615090, 'uploader': 'SlowdiveVEVO'} {'_type': 'url', 'ie_key': 'Youtube', 'id': 'u23v25GiB4s', 'url': 'https://www.youtube.com/watch?v=u23v25GiB4s', 'title': 'Slowdive // Slowdive (2017 Full Album)', 'description': None, 'duration': 3109.0, 'view_count': 441557, 'uploader': 'Sound