Arun Raghavan b5c48b97f6 Bump to WebRTC M131 release
Ongoing fixes and improvements, transient suppressor is gone. Also,
dropping isac because it doesn't seem to be useful, and is just build
system deadweight now.

Upstream references:

  Version: 131.0.6778.200
  WebRTC: 79aff54b0fa9238ce3518dd9eaf9610cd6f22e82
  Chromium: 2a19506ad24af755f2a215a4c61f775393e0db42
2024-12-26 12:55:16 -05:00

109 lines
3.4 KiB
C++

/*
* Copyright (c) 2018 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/aec3/reverb_frequency_response.h"
#include <stddef.h>
#include <algorithm>
#include <array>
#include <numeric>
#include "api/array_view.h"
#include "modules/audio_processing/aec3/aec3_common.h"
#include "rtc_base/checks.h"
namespace webrtc {
namespace {
// Computes the ratio of the energies between the direct path and the tail. The
// energy is computed in the power spectrum domain discarding the DC
// contributions.
float AverageDecayWithinFilter(
rtc::ArrayView<const float> freq_resp_direct_path,
rtc::ArrayView<const float> freq_resp_tail) {
// Skipping the DC for the ratio computation
constexpr size_t kSkipBins = 1;
RTC_CHECK_EQ(freq_resp_direct_path.size(), freq_resp_tail.size());
float direct_path_energy =
std::accumulate(freq_resp_direct_path.begin() + kSkipBins,
freq_resp_direct_path.end(), 0.f);
if (direct_path_energy == 0.f) {
return 0.f;
}
float tail_energy = std::accumulate(freq_resp_tail.begin() + kSkipBins,
freq_resp_tail.end(), 0.f);
return tail_energy / direct_path_energy;
}
} // namespace
ReverbFrequencyResponse::ReverbFrequencyResponse(
bool use_conservative_tail_frequency_response)
: use_conservative_tail_frequency_response_(
use_conservative_tail_frequency_response) {
tail_response_.fill(0.0f);
}
ReverbFrequencyResponse::~ReverbFrequencyResponse() = default;
void ReverbFrequencyResponse::Update(
const std::vector<std::array<float, kFftLengthBy2Plus1>>&
frequency_response,
int filter_delay_blocks,
const std::optional<float>& linear_filter_quality,
bool stationary_block) {
if (stationary_block || !linear_filter_quality) {
return;
}
Update(frequency_response, filter_delay_blocks, *linear_filter_quality);
}
void ReverbFrequencyResponse::Update(
const std::vector<std::array<float, kFftLengthBy2Plus1>>&
frequency_response,
int filter_delay_blocks,
float linear_filter_quality) {
rtc::ArrayView<const float> freq_resp_tail(
frequency_response[frequency_response.size() - 1]);
rtc::ArrayView<const float> freq_resp_direct_path(
frequency_response[filter_delay_blocks]);
float average_decay =
AverageDecayWithinFilter(freq_resp_direct_path, freq_resp_tail);
const float smoothing = 0.2f * linear_filter_quality;
average_decay_ += smoothing * (average_decay - average_decay_);
for (size_t k = 0; k < kFftLengthBy2Plus1; ++k) {
tail_response_[k] = freq_resp_direct_path[k] * average_decay_;
}
if (use_conservative_tail_frequency_response_) {
for (size_t k = 0; k < kFftLengthBy2Plus1; ++k) {
tail_response_[k] = std::max(freq_resp_tail[k], tail_response_[k]);
}
}
for (size_t k = 1; k < kFftLengthBy2; ++k) {
const float avg_neighbour =
0.5f * (tail_response_[k - 1] + tail_response_[k + 1]);
tail_response_[k] = std::max(tail_response_[k], avg_neighbour);
}
}
} // namespace webrtc