ABRManager

Overview

The ABRManager (ABR for Adaptive BitRate) is a class which facilitates the choice between multiple audio/video qualities in function of the current bandwidth, the network capacities and other specific settings set by the client.

It does so by receiving various values such as:

when network requests begin, progresses or end
stats about the bandwidth of the user
the current status of the buffer (how much of the buffer is left etc.)
DOM events
user settings (maximum authorized bitrate/width etc.)
the available qualities

With all those variables in hand, it then proposes the quality which seems to be the most adapted, that is the quality which:

will respect user settings (example: a Maximum bitrate is set)
will maximize the user experience (example: a quality too high for the network to handle would lead to excessive re-bufferings, but a too low would be not as pleasant to watch)