commit 1261b5caa38688778036411fca513548efd10e31
author Henrik Boström <hbos@webrtc.org> Fri Apr 17 09:41:32 2020 +0200
committer Commit Bot <commit-bot@chromium.org> Fri Apr 17 09:40:47 2020 +0000
tree 62bc85b094c4da296b5e77f70f01fe3df8299340
parent 2c80923230f5da7127cc981f3add9fed1a325cd0

[Adaptation] Move EffectiveDegradationPreference to RA-Processor.

This CL is part of the Call-Level Adaptation Processing design doc:
https://docs.google.com/document/d/1ZyC26yOCknrrcYa839ZWLxD6o6Gig5A3lVTh4E41074/edit?usp=sharing

The VideoStreamAdapter is responsible for generating adaptation
suggestions according to its DegradationPreference. Today there is one
DegradationPreference that you set, but internally the preference it
uses to make decisions is EffectiveDegradationPreference() which
reinterprets “balanced” as “maintain-resolution” if screenshare is used.

By moving the “effective” logic to the ResourceAdaptationProcessor, the
VideoStreamAdapter will not need to know about the type of track, and
the responsibility of the adapter is minimized. The “effective” logic
is non-standard and something we want to get rid of - until then, it
should be the responsibility of the processor to configure the adapter
to use the appropriate strategy, rather than for the adapter to know
about more states of the system than it needs to.

Future CLs will further minimize what the adapter needs to know, moving
"decision-making" logic to the Processor and "is adapt up allowed?"
logic to the Resources.

By removing the VideoInputMode enum the VideoStreamAdapter does not
know if we have input which has to be checked externally. Input
handling is followed-up on in the next CL.

Bug: webrtc:11172
Change-Id: I37ec9e7392f835cf8fef9829a2c945183f0e9b65
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/172927
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Evan Shrubsole <eshr@google.com>
Cr-Commit-Position: refs/heads/master@{#31096}