How to collect duration time of each client

I'm using PPV to control the playback of stream. I want to collect the data about how long one client watch a stream.
I can get client ID from PPV request, and get the sum duration by counting the number of PPV requests, but apparently it's not accurate.
I notice that there is a field "sessionid" in PPV request, does it means one distinct client connection? Can I use it to get the accurate watch time of a client ? Or, is there some other ways can do it

Hi,
you are right - you should use sessionid and sum all durations from PPV for given sessionid to get session time of particular session. You should not count number of PPV requests for sure. You should use "delta" field and current session duration is always "SessionDuration"=Sum(delta) for given "sessionid"

Thank you so much, that's very informative.