Youtube api Youtube:api/stats/qoe指标

我正在研究Youtube api，后端调用，如“watchtime”、“api/stats/qoe”。我找不到查询字符串度量的定义

比如说,， 我从“api/stats/qoe”中获得了这些指标，但我不知道它们是什么意思

fmt: 244
afmt: 251
cpn: 53sXf1ssOnU0CWnv
ei: unq1X4-zMdyN8wTS5aKACQ
el: detailpage
docid: 5HVHnUmRL6U
ns: yt
fexp: 23735347%2C23744176%2C23804281%2C23839597%2C23856950%2C23857949%2C23868322%2C23882502%2C23884386%2C23890959%2C23895671%2C23911055%2C23915993%2C23918597%2C23927767%2C23927767%2C23934970%2C23935844%2C23940248%2C23940704%2C23942338%2C23942633%2C23944779%2C23945479%2C23946420%2C23948841%2C23951620%2C23955372%2C23956524%2C23958572%2C23958692%2C23961732%2C23964530%2C23965224%2C23965756%2C23966254%2C23966412%2C23966725%2C23967043%2C23968560%2C23968756%2C23970847%2C23970974%2C23972773%2C24500568%2C24590298%2C24631715%2C24631744%2C3300106%2C3300131%2C3300164%2C3313321%2C3318700%2C3318773%2C3318889%2C3319220%2C3320540%2C3329303%2C9449243
cl: 342543027
seq: 3
cbr: Chrome
cbrver: 86.0.4240.198
c: WEB
cver: 2.20201117.01.00
cplayer: UNIPLAYER
cos: Windows
cosver: 10.0
cmt: 0.762:0.000,1.012:0.011,1.943:0.924,10.039:9.020
vps: 0.762:B,1.012:PL,10.039:PL
user_intent: 0.031
bwm: 10.039:3241322:1.280
bwe: 10.039:2551061
bat: 10.039:1:1
vis: 10.039:3
bh: 10.039:30.764
df: 10.039:0

有人能给我指出一个正确的方向，在那里我可以得到这些指标的定义吗？我特别寻找观看开始时间和观看结束时间的视频