Fix for SourceBuffer full error handling

[robwalch]

This PR will...

Manage appendBuffer SourceBuffer full errors correctly when audio bitrate is higher than video..

Why is this Pull Request needed?

When the audio bitrate is higher than the video bitrate, SourceBuffer full errors can occur on the audio buffer as the audio-stream-controller tries to keep up with the video buffer length.

The audio-stream-controller was going past maxMaxBufferLength when the video buffer exceeded that length prior to its value being reduced after the first buffer full error. Further more, the max length was not being reduced more than the current buffer length on the second error at which point the entire buffer was flushed. The entire buffer should only be flushed when the buffer that errored is starved (to remove back and forward buffer not used for playback).

Resolves issues:

Fixes #5328

[robwalch]

@pateljoel Please let me know if this change fixes the issue for you.

[pateljoel]

@robwalch Just tried this change on the bugfix/audio-source-buffer-full I don't think it worked.

I'm using Chrome on MacOS

[robwalch]

The error is expected.

Before this change, this error occurred multiple times. The internal error response flushed the audio buffer which interfered with playback.

Now, the append error occurs once, the audio buffer is not flushed, and playback continues but with a forward buffer limited to a maximum of five minutes instead of ten.

[robwalch]

Merged for v1.4.0-beta.1.