What does the video.buffered.length exactly tells?

Question

I noticed that when a html5 video is loading (buffering), it's buffered.length value is 2, and when it finish loading, it changes to 1.

Would this be a reliable way to know if a video is already stored in the cache (buffered.length == 1)? If not, am I missing something? Could someone explain me exactly what does this value tell me?

Answer 1

According to the Apple HTMLMediaElement documentation, buffered is TimeRanges

which is why the length property seems to be wrong

the buffered percentage can be calulated by using

video.buffered.end(0) / video.duration