commit d516b2585292819a34f6e206d5e830895cee41b6
author Henrik Boström <hbos@webrtc.org> Fri Apr 17 10:10:59 2020
committer Commit Bot <commit-bot@chromium.org> Fri Apr 17 11:45:50 2020
tree 3c16ca3eda3ee183fe556621a29a053efe3f72fb
parent da6cda839dac7d9d18eba8d365188fa94831e0b1

[Adaptation] Introduce VideoStreamInputState and its Provider.

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

The "input state" of a VideoStream, needed for adaptation and
decision-making, are: source resolution and frame rate, codec type and
min pixels per frame (based on encoder scaling settings). These values
are modified on the encoder queue of the VideoStreamEncoder.

But in order to unblock call-level adaptation processing, where
adaptation and decision making happens off the encoder queue, a snapshot
of the input states need to be available at point of processing:
introducing the VideoStreamInputState.

In this CL, the VideoStreamInputStateProvider is added to provide input
state snapshots across threads based on input from VideoStreamEncoder
and VideoStreamEncoderObserver.

The input state's HasInputFrameSizeAndFramesPerSecond() can now be
DCHECKed inside the VideoStreamAdapter in favor of having less
Adaptation::Status codes. Whether input is "sufficient" for adaptation
is now the responsibility of the Processor. (Goal: adapter is purely a
Adaptation generator and apply-er.)

Somewhat tangental, this CL also deletes VideoStreamEncoder-specific
methods from ResourceAdaptationProcessorInterface making them an
implementation detail of ResourceAdaptationProcessor. In a future CL,
the "processor" will be split up into a "processor" part and a "video
stream encoder resource manager" part - more on that later.

Bug: webrtc:11172
Change-Id: Id9b158f569db0140b75360aaf0f7e2e28fb924f4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/172928
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@{#31098}