commit 08127a9449f5e1778382d453267abbe9354b0095
author Erik Språng <sprang@webrtc.org> Wed Nov 16 15:41:30 2016
committer Erik Språng <sprang@webrtc.org> Wed Nov 16 15:41:45 2016
tree 7e5afcf10721c62ed4e61d0ed79edbe32f2aa1d6
parent 779017d989b01b53954636a7237e81dd249e5b84

Reland #2 of Issue 2434073003: Extract bitrate allocation ...

This is yet another reland of https://codereview.webrtc.org/2434073003/
including two fixes:

1. SimulcastRateAllocator did not handle the screenshare settings properly for numSimulcastStreams = 1. Additional test case was added for that.
2. In VideoSender, when rate allocation is updated after setting a new VideoCodec config, only update the state of the EncoderParameters, but don't actually run SetRateAllocation on the encoder itself. This caused some problems upstreams.

Please review only the changes after patch set 1.

Original description:

Extract bitrate allocation of spatial/temporal layers out of codec impl.

This CL makes a number of intervowen changes:

* Add BitrateAllocation struct, that contains a codec independent view
  of how the target bitrate is distributed over spatial and temporal
  layers.

* Adds the BitrateAllocator interface, which takes a bitrate and frame
  rate and produces a BitrateAllocation.

* A default (non layered) implementation is added, and
  SimulcastRateAllocator is extended to fully handle VP8 allocation.
  This includes capturing TemporalLayer instances created by the
  encoder.

* ViEEncoder now owns both the bitrate allocator and the temporal layer
  factories for VP8. This allows allocation to happen fully outside of
  the encoder implementation.

This refactoring will make it possible for ViEEncoder to signal the
full picture of target bitrates to the RTCP module.

BUG=webrtc:6301
R=stefan@webrtc.org

Review URL: https://codereview.webrtc.org/2510583002 .

Cr-Commit-Position: refs/heads/master@{#15105}