Video.js v10 skin
R-52 Chart Recorder
The timeline is chart paper. A pen writes the video's sound onto it as it plays, so you can see where people talk and where it goes quiet before you seek.
Fault
How to read it
Red ink is what has played. The faint pencil line ahead of the pen is the rest of the sound, drawn from the audio before you press Run, so loud and quiet parts are visible before you get there.
Gauges
BUF is seconds buffered ahead of the pen, DROP is dropped video frames from the browser, LVL is the sound level under the pen. The lamp is green when running, amber while loading, red on a fault.
Keys
Space or K run and hold. Left and right move 5 seconds, up and down set volume, M mutes, F is fullscreen, 0 to 9 jump through the chart.