This CL refactors the computation of band energy and spectral
cross-correlation coefficients by moving and optimizing
the code from ComputeBandCoefficients, ComputeBandEnergies and
ComputeSpectralCrossCorrelation into a single class (named
BandFeaturesExtractor).
This change will also help replacing FFT library in the RNN VAD.
Bug: webrtc:10480
Change-Id: I6cefa23e8f3bc8de6eb09d3ea434699d5e19124e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/129726
Commit-Queue: Alessio Bazzica <alessiob@webrtc.org>
Reviewed-by: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27535}