Pretty-Fast Fast Fourier Transform is a 3rd party FFT C library meant to
replace other FFT libraries in WebRTC (see https://crbug.com/webrtc/9577).
This CL adds a WebRTC wrapper meant to be used inside the Audio Processing
Module (APM). As a first step, it only supports aligned memory allocated
via PFFFT. Support for the C++ standard library containers will be done
afterwards since it requires careful investigation and benchmarking (because
PFFFT uses SIMD optimizations).
The wrapper pre-allocates a scratch buffer to avoid VLA.
Bug: webrtc:9577
Change-Id: Ied00c3d3b1df292024f608ccf0ed1917d6e92e56
Reviewed-on: https://webrtc-review.googlesource.com/c/122563
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Max Morin <maxmorin@webrtc.org>
Commit-Queue: Alessio Bazzica <alessiob@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26808}
