混沌大学来回答这个问题，请看视频：
{!– PGC_VIDEO:{“thumb_fingerprint”: 15001293315260608821, “status”: 0, “thumb_height”: 360, “thumb_url”: “5b520002d15a3a5e66a5”, “thumb_neardup_id”: 7987872297247713224, “neardup_id”: 7839402853215834277, “vid”: “1f7769385e6d4f51a7b430d4854206aa”, “user_id”: 5441164736, “sp”: “toutiao”, “vposter”: “http://p0.pstatp.com/origin/5b520002d15a3a5e66a5”, “external_covers”: [{“mimetype”: “webp”, “source”: “dynpost”, “thumb_height”: 360, “thumb_url”: “5c4e000167b7870b1df9”, “thumb_width”: 450}], “thumb_width”: 480, “item_id”: 6515317475523953155, “vu”: “1f7769385e6d4f51a7b430d4854206aa”, “duration”: 120, “media_id”: 5441164736, “group_id”: 6515317475523953155, “hash_id”: 7839402853215834277, “vname”: “/u6bd4/u7279/u5e01/u8fd9/u4e48/u706b/uff0c/u4e00/u5207/u90fd/u6e90/u4e8e/u8fd9/u4e2a/u4eba/uff1f/uff01.avi”, “md5”: “dc37c0fa2358ce49d754d2c342de8964”, “video_size”: {“high”: {“duration”: 120.92, “h”: 480, “subjective_score”: 0, “w”: 640, “file_size”: 3183116}, “ultra”: {“duration”: 120.92, “h”: 576, “subjective_score”: 0, “w”: 768, “file_size”: 5297702}, “normal”: {“duration”: 120.92, “h”: 360, “subjective_score”: 0, “w”: 480, “file_size”: 2454152}}} –}