commit d860523112263f9c8f29b95658c89215fbd95a16
author peah <peah@webrtc.org> Tue Nov 24 07:05:44 2015
committer Commit bot <commit-bot@chromium.org> Tue Nov 24 07:05:49 2015
tree 29803383a62369701adac816371cb71b2dff19bf
parent 70bed7d4153855e508954df928ad2d9224445dc2

First part of the preparatory work before the actual work for solving the ducking problem starts.

This works aims to:
-More clearly separate the functionalities in the AEC.
-Make the inputs and outputs to functions more clear (currently the state struct is often passed as a parameter to the functions and the functions use members of the state both as inputs and outputs, which reduces the readability of the code and makes it difficult to change/refactor.

What is done in this CL:
-Most of what belongs to the echo subtraction functionality has been moved to a separate function.
-The NonLinearProcessing function has been renamed to EchoSuppressor which I think is more appropriate.
-Part of the code was replaced by a call to the TimeToFrequency function (which was also suggested by an existing todo).
-For consistency, a function FrequencyToTime doing the opposite of TimeToFrequency was added and part of the code was moved to that.
-The ScaleErrorSignal function was changed to no longer have the state as an input parameter. This entailed also changing the corresponding assembly optimized files accordingly.

Testing:
-The changes have been tested for bitexactness on Linux using a fairly extensive test.
-All the unittests pass on linux.

BUG=webrtc:5201

Review URL: https://codereview.webrtc.org/1455163006

Cr-Commit-Position: refs/heads/master@{#10764}