Ideally the nimble streamer server would periodically (say every 10 seconds) set a timestamp in the video stream's meta data and then the client would read this time and make it available through some callback function. And in this callback function we would compare the video streams timestamp with the clients time and thus calculate the latency.

Or maybe expose a callback function that gets called every time the "latency_tolerence" gets exceeded?

Hi,
there is no such methods now you are right. Maybe we will add something like this later. Thanks for the idea