| /* |
| * 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/echo_audibility.h" |
| |
| #include <algorithm> |
| #include <cmath> |
| |
| #include "modules/audio_processing/aec3/aec3_common.h" |
| #include "modules/audio_processing/aec3/matrix_buffer.h" |
| #include "modules/audio_processing/aec3/stationarity_estimator.h" |
| #include "modules/audio_processing/aec3/vector_buffer.h" |
| |
| namespace webrtc { |
| |
| EchoAudibility::EchoAudibility(bool use_render_stationarity_at_init) |
| : use_render_stationarity_at_init_(use_render_stationarity_at_init) { |
| Reset(); |
| } |
| |
| EchoAudibility::~EchoAudibility() = default; |
| |
| void EchoAudibility::Update(const RenderBuffer& render_buffer, |
| int delay_blocks, |
| bool external_delay_seen, |
| float reverb_decay) { |
| UpdateRenderNoiseEstimator(render_buffer.GetSpectrumBuffer(), |
| render_buffer.GetBlockBuffer(), |
| external_delay_seen); |
| |
| if (external_delay_seen || use_render_stationarity_at_init_) { |
| UpdateRenderStationarityFlags(render_buffer, delay_blocks, reverb_decay); |
| } |
| } |
| |
| void EchoAudibility::Reset() { |
| render_stationarity_.Reset(); |
| non_zero_render_seen_ = false; |
| render_spectrum_write_prev_ = absl::nullopt; |
| } |
| |
| void EchoAudibility::UpdateRenderStationarityFlags( |
| const RenderBuffer& render_buffer, |
| int delay_blocks, |
| float reverb_decay) { |
| const VectorBuffer& spectrum_buffer = render_buffer.GetSpectrumBuffer(); |
| int idx_at_delay = |
| spectrum_buffer.OffsetIndex(spectrum_buffer.read, delay_blocks); |
| |
| int num_lookahead = render_buffer.Headroom() - delay_blocks + 1; |
| num_lookahead = std::max(0, num_lookahead); |
| |
| render_stationarity_.UpdateStationarityFlags(spectrum_buffer, idx_at_delay, |
| num_lookahead, reverb_decay); |
| } |
| |
| void EchoAudibility::UpdateRenderNoiseEstimator( |
| const VectorBuffer& spectrum_buffer, |
| const MatrixBuffer& block_buffer, |
| bool external_delay_seen) { |
| if (!render_spectrum_write_prev_) { |
| render_spectrum_write_prev_ = spectrum_buffer.write; |
| render_block_write_prev_ = block_buffer.write; |
| return; |
| } |
| int render_spectrum_write_current = spectrum_buffer.write; |
| if (!non_zero_render_seen_ && !external_delay_seen) { |
| non_zero_render_seen_ = !IsRenderTooLow(block_buffer); |
| } |
| if (non_zero_render_seen_) { |
| for (int idx = render_spectrum_write_prev_.value(); |
| idx != render_spectrum_write_current; |
| idx = spectrum_buffer.DecIndex(idx)) { |
| render_stationarity_.UpdateNoiseEstimator(spectrum_buffer.buffer[idx]); |
| } |
| } |
| render_spectrum_write_prev_ = render_spectrum_write_current; |
| } |
| |
| bool EchoAudibility::IsRenderTooLow(const MatrixBuffer& block_buffer) { |
| bool too_low = false; |
| const int render_block_write_current = block_buffer.write; |
| if (render_block_write_current == render_block_write_prev_) { |
| too_low = true; |
| } else { |
| for (int idx = render_block_write_prev_; idx != render_block_write_current; |
| idx = block_buffer.IncIndex(idx)) { |
| auto block = block_buffer.buffer[idx][0]; |
| auto r = std::minmax_element(block.cbegin(), block.cend()); |
| float max_abs = std::max(std::fabs(*r.first), std::fabs(*r.second)); |
| if (max_abs < 10) { |
| too_low = true; // Discards all blocks if one of them is too low. |
| break; |
| } |
| } |
| } |
| render_block_write_prev_ = render_block_write_current; |
| return too_low; |
| } |
| |
| } // namespace webrtc |