This CL introduces the Adaptation class used by VideoStreamRestrictor.
This refactors the AdaptationTarget, AdaptationTargetOrReason,
CannotAdaptReason and AdaptationAction.
What is publicly exposed is simply a Status code. If it's kValid then
we can adapt, otherwise the status code describes why we can't adapt
(just like CannotAdaptReason prior to this CL). This means
AdaptationTargetOrReason is no longer needed. Target+reason are merged.
The other classes are renamed and moved and put in the private
namespace of Adaptation: Only the VideoStreamAdapter (now a friend
class of Adaptation) and its inner class VideoSourceRestrictor needs to
know how to execute the adaptation.
Publicly, you can now tell the effects of the adaptation without
applying it with PeekNextRestrictions() - both current and next steps
are described in terms of VideoSourceRestrictions. The rest are hidden.
This would make it possible, in the future, for a Resource to accept or
reject a proposed Adaptation by examining the resulting frame rate and
resolution described by the resulting restrictions. E.g. even if we are
not overusing bandwidth at the moment, the BW resource can prevent us
from applying a restriction that would exceed the BW limit before we
apply it.
This CL also moves input to a SetInput() method, and Increase/Decrease
methods of VideoSourceRestrictor are made private in favor of
ApplyAdaptationSteps().
Bug: webrtc:11393
Change-Id: Ie5e2181836ab3713b8021c1a152694ca745aeb0d
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/170111
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@{#30794}
This introduces AdaptationTargetOrReason and gets rid of
VideoStreamAdapter's dependency on the VideoStreamEncoderObserver.
AdaptationTargetOrReason provides information about why an adaptation
target could not be returned from GetAdaptUpTarget() and
GetAdaptDownTarget() with the enum CannotAdaptReason and the boolean
min_pixel_limit_reached.
While the enum value is not used by the caller in this CL, it makes
explicit reasons the adapter is allowed to reject a target. TODOs are
added documenting how we want to get rid of kAwaitingPreviousAdaptation
for multi-stream use cases and how kIsBitrateConstrained can be
rephrased as a resource problem in the future.
min_pixel_limit_reached() allows us to move the responsibility of stats
reporting to the module. A TODO documents how this could be replaced by
kLimitReached or similar logic in the future.
Bug: webrtc:11393
Change-Id: Iffdd8ddb01641937741fac353174ea14168477ce
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/169928
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Evan Shrubsole <eshr@google.com>
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30789}
