0cbb58e046
This is a reland of 87a7b82520b83a6cf42da27cdc46142c2eb6248c Original change's description: > Refactoring of the noise suppressor and adding true multichannel support > > This CL adds proper multichannel support to the noise suppressor. > To accomplish that in a safe way, a full refactoring of the noise > suppressor code has been done. > > Due to floating point precision, the changes made are not entirely > bitexact. They are, however, very close to being bitexact. > > As a safety measure, the former noise suppressor code is preserved > and a kill-switch is added to allow revering to the legacy noise > suppressor in case issues arise. > > Bug: webrtc:10895, b/143344262 > Change-Id: I0b071011b23265ac12e6d4b3956499d122286657 > Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/158407 > Commit-Queue: Per Åhgren <peah@webrtc.org> > Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org> > Cr-Commit-Position: refs/heads/master@{#29646} Bug: webrtc:10895, b/143344262 Change-Id: I236f1e67bb0baa4e30908a4cf7a8a7bb55fbced3 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/158747 Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org> Commit-Queue: Per Åhgren <peah@webrtc.org> Cr-Commit-Position: refs/heads/master@{#29663}
85 lines
2.2 KiB
C++
85 lines
2.2 KiB
C++
/*
|
|
* Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license
|
|
* that can be found in the LICENSE file in the root of the source
|
|
* tree. An additional intellectual property rights grant can be found
|
|
* in the file PATENTS. All contributing project authors may
|
|
* be found in the AUTHORS file in the root of the source tree.
|
|
*/
|
|
|
|
#include "modules/audio_processing/ns/fast_math.h"
|
|
|
|
#include <math.h>
|
|
#include <stdint.h>
|
|
|
|
#include "rtc_base/checks.h"
|
|
|
|
namespace webrtc {
|
|
|
|
namespace {
|
|
|
|
float FastLog2f(float in) {
|
|
RTC_DCHECK_GT(in, .0f);
|
|
// Read and interpret float as uint32_t and then cast to float.
|
|
// This is done to extract the exponent (bits 30 - 23).
|
|
// "Right shift" of the exponent is then performed by multiplying
|
|
// with the constant (1/2^23). Finally, we subtract a constant to
|
|
// remove the bias (https://en.wikipedia.org/wiki/Exponent_bias).
|
|
union {
|
|
float dummy;
|
|
uint32_t a;
|
|
} x = {in};
|
|
float out = x.a;
|
|
out *= 1.1920929e-7f; // 1/2^23
|
|
out -= 126.942695f; // Remove bias.
|
|
return out;
|
|
}
|
|
|
|
} // namespace
|
|
|
|
float SqrtFastApproximation(float f) {
|
|
// TODO(peah): Add fast approximate implementation.
|
|
return sqrtf(f);
|
|
}
|
|
|
|
float Pow2Approximation(float p) {
|
|
// TODO(peah): Add fast approximate implementation.
|
|
return powf(2.f, p);
|
|
}
|
|
|
|
float PowApproximation(float x, float p) {
|
|
return Pow2Approximation(p * FastLog2f(x));
|
|
}
|
|
|
|
float LogApproximation(float x) {
|
|
constexpr float kLogOf2 = 0.69314718056f;
|
|
return FastLog2f(x) * kLogOf2;
|
|
}
|
|
|
|
void LogApproximation(rtc::ArrayView<const float> x, rtc::ArrayView<float> y) {
|
|
for (size_t k = 0; k < x.size(); ++k) {
|
|
y[k] = LogApproximation(x[k]);
|
|
}
|
|
}
|
|
|
|
float ExpApproximation(float x) {
|
|
constexpr float kLog10Ofe = 0.4342944819f;
|
|
return PowApproximation(10.f, x * kLog10Ofe);
|
|
}
|
|
|
|
void ExpApproximation(rtc::ArrayView<const float> x, rtc::ArrayView<float> y) {
|
|
for (size_t k = 0; k < x.size(); ++k) {
|
|
y[k] = ExpApproximation(x[k]);
|
|
}
|
|
}
|
|
|
|
void ExpApproximationSignFlip(rtc::ArrayView<const float> x,
|
|
rtc::ArrayView<float> y) {
|
|
for (size_t k = 0; k < x.size(); ++k) {
|
|
y[k] = ExpApproximation(-x[k]);
|
|
}
|
|
}
|
|
|
|
} // namespace webrtc
|