We should track buffering events

[sjparkinson]

o-video/src/js/video.js

Line 241 in 166e5a2

addEvents(this, ['playing', 'pause', 'ended', 'progress', 'seeked', 'error', 'stalled']);

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

Relates to https://trello.com/c/PhYVid5N/276-loading-videos-on-ftcom.

We've only just enabled streaming miss on the next media API's Fastly service, which should have dramatic improvements to the video load times.

[JakeChampion]

How is the waiting event different from the stalled event we already fire?
https://html.spec.whatwg.org/multipage/media.html#event-media-waiting
https://html.spec.whatwg.org/multipage/media.html#event-media-stalled

[sjparkinson]

The stall timeout is a user-agent defined length of time, which should be about three seconds. When a media element that is actively attempting to obtain media data has failed to receive any data for a duration equal to the stall timeout, the user agent must queue a task to fire an event named stalled at the element.

from https://html.spec.whatwg.org/multipage/media.html#loading-the-media-resource:event-media-stalled.

Which to me sounds more about hard errors. Whereas the waiting event is more around performance, how often our users are seeing a spinning circle.