Where to get/or write an applet like this?

[carlyai]

On YouTube there is a bit of code in the stream player that displays: connection speed, network activity, buffer health, latency, etc. (as in the picture).

Where can I download this little display or how to write the code to imbed it in my video stream player?

Any information on where to look for something like this. 

 

[jackdd]

This information comes from certain events or functions, for example:

https://developer.mozilla.org/en-US/docs/Web/Guide/Events/Media_events

https://developer.mozilla.org/en-US/docs/Web/API/VideoPlaybackQuality