How to calculate buffer ratio/ time for analytics purposes

[shubhamvashisht]

How to calculate buffer ratio/ time for analytics purposes

[tonihei]

compute the time playback was stopped due to buffering

You probably want PlaybackStats.getTotalRebufferTimeMs() if I understand your goal correctly. Specifically, this counts the time from PLAYBACK_STATE_BUFFERING only (= the time a user actively waited for playback). PLAYBACK_STATE_PAUSED_BUFFERING is not included because the assumption is that a paused playback is not something a user is actively waiting for.

understand click to playtime of a stream

Most likely this is getTotalPlayTimeMs or getTotalPlayAndWaitTimeMs depending on whether you want to include the wait times or not.

How to calculate buffer ratio

If you are just after the ratios, there are also the predefined getRebufferTimeRatio and getWaitTimeRatio methods that might be of interest

[shubhamvashisht]

as per docs PlaybackStats.getTotalRebufferTimeMs() does not include initial buffer and buffer after user has seeks.
to understand the full picture we want to include those as well.
does getTotalWaitTimeMs() makes more sense?

[tonihei]

does getTotalWaitTimeMs() makes more sense?

This depends on your exact needs. Please read the method documentation carefully to know what is included and what isn't. The method also links to the other 'wait time' methods like getTotalJoinTimeMs or getTotalSeekTimeMs.