diff options
Diffstat (limited to 'webrtc/modules/audio_processing/aec3/render_delay_buffer.cc')
| -rw-r--r-- | webrtc/modules/audio_processing/aec3/render_delay_buffer.cc | 523 |
1 files changed, 523 insertions, 0 deletions
diff --git a/webrtc/modules/audio_processing/aec3/render_delay_buffer.cc b/webrtc/modules/audio_processing/aec3/render_delay_buffer.cc new file mode 100644 index 0000000..7bebc6f --- /dev/null +++ b/webrtc/modules/audio_processing/aec3/render_delay_buffer.cc @@ -0,0 +1,523 @@ +/* + * 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/render_delay_buffer.h" + +#include <string.h> + +#include <algorithm> +#include <cmath> +#include <memory> +#include <numeric> +#include <vector> + +#include "absl/types/optional.h" +#include "api/array_view.h" +#include "api/audio/echo_canceller3_config.h" +#include "modules/audio_processing/aec3/aec3_common.h" +#include "modules/audio_processing/aec3/aec3_fft.h" +#include "modules/audio_processing/aec3/alignment_mixer.h" +#include "modules/audio_processing/aec3/block_buffer.h" +#include "modules/audio_processing/aec3/decimator.h" +#include "modules/audio_processing/aec3/downsampled_render_buffer.h" +#include "modules/audio_processing/aec3/fft_buffer.h" +#include "modules/audio_processing/aec3/fft_data.h" +#include "modules/audio_processing/aec3/render_buffer.h" +#include "modules/audio_processing/aec3/spectrum_buffer.h" +#include "modules/audio_processing/logging/apm_data_dumper.h" +#include "rtc_base/atomic_ops.h" +#include "rtc_base/checks.h" +#include "rtc_base/logging.h" +#include "system_wrappers/include/field_trial.h" + +namespace webrtc { +namespace { + +bool UpdateCaptureCallCounterOnSkippedBlocks() { + return !field_trial::IsEnabled( + "WebRTC-Aec3RenderBufferCallCounterUpdateKillSwitch"); +} + +class RenderDelayBufferImpl final : public RenderDelayBuffer { + public: + RenderDelayBufferImpl(const EchoCanceller3Config& config, + int sample_rate_hz, + size_t num_render_channels); + RenderDelayBufferImpl() = delete; + ~RenderDelayBufferImpl() override; + + void Reset() override; + BufferingEvent Insert( + const std::vector<std::vector<std::vector<float>>>& block) override; + BufferingEvent PrepareCaptureProcessing() override; + void HandleSkippedCaptureProcessing() override; + bool AlignFromDelay(size_t delay) override; + void AlignFromExternalDelay() override; + size_t Delay() const override { return ComputeDelay(); } + size_t MaxDelay() const override { + return blocks_.buffer.size() - 1 - buffer_headroom_; + } + RenderBuffer* GetRenderBuffer() override { return &echo_remover_buffer_; } + + const DownsampledRenderBuffer& GetDownsampledRenderBuffer() const override { + return low_rate_; + } + + int BufferLatency() const; + void SetAudioBufferDelay(int delay_ms) override; + bool HasReceivedBufferDelay() override; + + private: + static int instance_count_; + std::unique_ptr<ApmDataDumper> data_dumper_; + const Aec3Optimization optimization_; + const EchoCanceller3Config config_; + const bool update_capture_call_counter_on_skipped_blocks_; + const float render_linear_amplitude_gain_; + const rtc::LoggingSeverity delay_log_level_; + size_t down_sampling_factor_; + const int sub_block_size_; + BlockBuffer blocks_; + SpectrumBuffer spectra_; + FftBuffer ffts_; + absl::optional<size_t> delay_; + RenderBuffer echo_remover_buffer_; + DownsampledRenderBuffer low_rate_; + AlignmentMixer render_mixer_; + Decimator render_decimator_; + const Aec3Fft fft_; + std::vector<float> render_ds_; + const int buffer_headroom_; + bool last_call_was_render_ = false; + int num_api_calls_in_a_row_ = 0; + int max_observed_jitter_ = 1; + int64_t capture_call_counter_ = 0; + int64_t render_call_counter_ = 0; + bool render_activity_ = false; + size_t render_activity_counter_ = 0; + absl::optional<int> external_audio_buffer_delay_; + bool external_audio_buffer_delay_verified_after_reset_ = false; + size_t min_latency_blocks_ = 0; + size_t excess_render_detection_counter_ = 0; + + int MapDelayToTotalDelay(size_t delay) const; + int ComputeDelay() const; + void ApplyTotalDelay(int delay); + void InsertBlock(const std::vector<std::vector<std::vector<float>>>& block, + int previous_write); + bool DetectActiveRender(rtc::ArrayView<const float> x) const; + bool DetectExcessRenderBlocks(); + void IncrementWriteIndices(); + void IncrementLowRateReadIndices(); + void IncrementReadIndices(); + bool RenderOverrun(); + bool RenderUnderrun(); +}; + +int RenderDelayBufferImpl::instance_count_ = 0; + +RenderDelayBufferImpl::RenderDelayBufferImpl(const EchoCanceller3Config& config, + int sample_rate_hz, + size_t num_render_channels) + : data_dumper_( + new ApmDataDumper(rtc::AtomicOps::Increment(&instance_count_))), + optimization_(DetectOptimization()), + config_(config), + update_capture_call_counter_on_skipped_blocks_( + UpdateCaptureCallCounterOnSkippedBlocks()), + render_linear_amplitude_gain_( + std::pow(10.0f, config_.render_levels.render_power_gain_db / 20.f)), + delay_log_level_(config_.delay.log_warning_on_delay_changes + ? rtc::LS_WARNING + : rtc::LS_VERBOSE), + down_sampling_factor_(config.delay.down_sampling_factor), + sub_block_size_(static_cast<int>(down_sampling_factor_ > 0 + ? kBlockSize / down_sampling_factor_ + : kBlockSize)), + blocks_(GetRenderDelayBufferSize(down_sampling_factor_, + config.delay.num_filters, + config.filter.refined.length_blocks), + NumBandsForRate(sample_rate_hz), + num_render_channels, + kBlockSize), + spectra_(blocks_.buffer.size(), num_render_channels), + ffts_(blocks_.buffer.size(), num_render_channels), + delay_(config_.delay.default_delay), + echo_remover_buffer_(&blocks_, &spectra_, &ffts_), + low_rate_(GetDownSampledBufferSize(down_sampling_factor_, + config.delay.num_filters)), + render_mixer_(num_render_channels, config.delay.render_alignment_mixing), + render_decimator_(down_sampling_factor_), + fft_(), + render_ds_(sub_block_size_, 0.f), + buffer_headroom_(config.filter.refined.length_blocks) { + RTC_DCHECK_EQ(blocks_.buffer.size(), ffts_.buffer.size()); + RTC_DCHECK_EQ(spectra_.buffer.size(), ffts_.buffer.size()); + for (size_t i = 0; i < blocks_.buffer.size(); ++i) { + RTC_DCHECK_EQ(blocks_.buffer[i][0].size(), ffts_.buffer[i].size()); + RTC_DCHECK_EQ(spectra_.buffer[i].size(), ffts_.buffer[i].size()); + } + + Reset(); +} + +RenderDelayBufferImpl::~RenderDelayBufferImpl() = default; + +// Resets the buffer delays and clears the reported delays. +void RenderDelayBufferImpl::Reset() { + last_call_was_render_ = false; + num_api_calls_in_a_row_ = 1; + min_latency_blocks_ = 0; + excess_render_detection_counter_ = 0; + + // Initialize the read index to one sub-block before the write index. + low_rate_.read = low_rate_.OffsetIndex(low_rate_.write, sub_block_size_); + + // Check for any external audio buffer delay and whether it is feasible. + if (external_audio_buffer_delay_) { + const int headroom = 2; + size_t audio_buffer_delay_to_set; + // Minimum delay is 1 (like the low-rate render buffer). + if (*external_audio_buffer_delay_ <= headroom) { + audio_buffer_delay_to_set = 1; + } else { + audio_buffer_delay_to_set = *external_audio_buffer_delay_ - headroom; + } + + audio_buffer_delay_to_set = std::min(audio_buffer_delay_to_set, MaxDelay()); + + // When an external delay estimate is available, use that delay as the + // initial render buffer delay. + ApplyTotalDelay(audio_buffer_delay_to_set); + delay_ = ComputeDelay(); + + external_audio_buffer_delay_verified_after_reset_ = false; + } else { + // If an external delay estimate is not available, use that delay as the + // initial delay. Set the render buffer delays to the default delay. + ApplyTotalDelay(config_.delay.default_delay); + + // Unset the delays which are set by AlignFromDelay. + delay_ = absl::nullopt; + } +} + +// Inserts a new block into the render buffers. +RenderDelayBuffer::BufferingEvent RenderDelayBufferImpl::Insert( + const std::vector<std::vector<std::vector<float>>>& block) { + ++render_call_counter_; + if (delay_) { + if (!last_call_was_render_) { + last_call_was_render_ = true; + num_api_calls_in_a_row_ = 1; + } else { + if (++num_api_calls_in_a_row_ > max_observed_jitter_) { + max_observed_jitter_ = num_api_calls_in_a_row_; + RTC_LOG_V(delay_log_level_) + << "New max number api jitter observed at render block " + << render_call_counter_ << ": " << num_api_calls_in_a_row_ + << " blocks"; + } + } + } + + // Increase the write indices to where the new blocks should be written. + const int previous_write = blocks_.write; + IncrementWriteIndices(); + + // Allow overrun and do a reset when render overrun occurrs due to more render + // data being inserted than capture data is received. + BufferingEvent event = + RenderOverrun() ? BufferingEvent::kRenderOverrun : BufferingEvent::kNone; + + // Detect and update render activity. + if (!render_activity_) { + render_activity_counter_ += DetectActiveRender(block[0][0]) ? 1 : 0; + render_activity_ = render_activity_counter_ >= 20; + } + + // Insert the new render block into the specified position. + InsertBlock(block, previous_write); + + if (event != BufferingEvent::kNone) { + Reset(); + } + + return event; +} + +void RenderDelayBufferImpl::HandleSkippedCaptureProcessing() { + if (update_capture_call_counter_on_skipped_blocks_) { + ++capture_call_counter_; + } +} + +// Prepares the render buffers for processing another capture block. +RenderDelayBuffer::BufferingEvent +RenderDelayBufferImpl::PrepareCaptureProcessing() { + RenderDelayBuffer::BufferingEvent event = BufferingEvent::kNone; + ++capture_call_counter_; + + if (delay_) { + if (last_call_was_render_) { + last_call_was_render_ = false; + num_api_calls_in_a_row_ = 1; + } else { + if (++num_api_calls_in_a_row_ > max_observed_jitter_) { + max_observed_jitter_ = num_api_calls_in_a_row_; + RTC_LOG_V(delay_log_level_) + << "New max number api jitter observed at capture block " + << capture_call_counter_ << ": " << num_api_calls_in_a_row_ + << " blocks"; + } + } + } + + if (DetectExcessRenderBlocks()) { + // Too many render blocks compared to capture blocks. Risk of delay ending + // up before the filter used by the delay estimator. + RTC_LOG_V(delay_log_level_) + << "Excess render blocks detected at block " << capture_call_counter_; + Reset(); + event = BufferingEvent::kRenderOverrun; + } else if (RenderUnderrun()) { + // Don't increment the read indices of the low rate buffer if there is a + // render underrun. + RTC_LOG_V(delay_log_level_) + << "Render buffer underrun detected at block " << capture_call_counter_; + IncrementReadIndices(); + // Incrementing the buffer index without increasing the low rate buffer + // index means that the delay is reduced by one. + if (delay_ && *delay_ > 0) + delay_ = *delay_ - 1; + event = BufferingEvent::kRenderUnderrun; + } else { + // Increment the read indices in the render buffers to point to the most + // recent block to use in the capture processing. + IncrementLowRateReadIndices(); + IncrementReadIndices(); + } + + echo_remover_buffer_.SetRenderActivity(render_activity_); + if (render_activity_) { + render_activity_counter_ = 0; + render_activity_ = false; + } + + return event; +} + +// Sets the delay and returns a bool indicating whether the delay was changed. +bool RenderDelayBufferImpl::AlignFromDelay(size_t delay) { + RTC_DCHECK(!config_.delay.use_external_delay_estimator); + if (!external_audio_buffer_delay_verified_after_reset_ && + external_audio_buffer_delay_ && delay_) { + int difference = static_cast<int>(delay) - static_cast<int>(*delay_); + RTC_LOG_V(delay_log_level_) + << "Mismatch between first estimated delay after reset " + "and externally reported audio buffer delay: " + << difference << " blocks"; + external_audio_buffer_delay_verified_after_reset_ = true; + } + if (delay_ && *delay_ == delay) { + return false; + } + delay_ = delay; + + // Compute the total delay and limit the delay to the allowed range. + int total_delay = MapDelayToTotalDelay(*delay_); + total_delay = + std::min(MaxDelay(), static_cast<size_t>(std::max(total_delay, 0))); + + // Apply the delay to the buffers. + ApplyTotalDelay(total_delay); + return true; +} + +void RenderDelayBufferImpl::SetAudioBufferDelay(int delay_ms) { + if (!external_audio_buffer_delay_) { + RTC_LOG_V(delay_log_level_) + << "Receiving a first externally reported audio buffer delay of " + << delay_ms << " ms."; + } + + // Convert delay from milliseconds to blocks (rounded down). + external_audio_buffer_delay_ = delay_ms / 4; +} + +bool RenderDelayBufferImpl::HasReceivedBufferDelay() { + return external_audio_buffer_delay_.has_value(); +} + +// Maps the externally computed delay to the delay used internally. +int RenderDelayBufferImpl::MapDelayToTotalDelay( + size_t external_delay_blocks) const { + const int latency_blocks = BufferLatency(); + return latency_blocks + static_cast<int>(external_delay_blocks); +} + +// Returns the delay (not including call jitter). +int RenderDelayBufferImpl::ComputeDelay() const { + const int latency_blocks = BufferLatency(); + int internal_delay = spectra_.read >= spectra_.write + ? spectra_.read - spectra_.write + : spectra_.size + spectra_.read - spectra_.write; + + return internal_delay - latency_blocks; +} + +// Set the read indices according to the delay. +void RenderDelayBufferImpl::ApplyTotalDelay(int delay) { + RTC_LOG_V(delay_log_level_) + << "Applying total delay of " << delay << " blocks."; + blocks_.read = blocks_.OffsetIndex(blocks_.write, -delay); + spectra_.read = spectra_.OffsetIndex(spectra_.write, delay); + ffts_.read = ffts_.OffsetIndex(ffts_.write, delay); +} + +void RenderDelayBufferImpl::AlignFromExternalDelay() { + RTC_DCHECK(config_.delay.use_external_delay_estimator); + if (external_audio_buffer_delay_) { + const int64_t delay = render_call_counter_ - capture_call_counter_ + + *external_audio_buffer_delay_; + const int64_t delay_with_headroom = + delay - config_.delay.delay_headroom_samples / kBlockSize; + ApplyTotalDelay(delay_with_headroom); + } +} + +// Inserts a block into the render buffers. +void RenderDelayBufferImpl::InsertBlock( + const std::vector<std::vector<std::vector<float>>>& block, + int previous_write) { + auto& b = blocks_; + auto& lr = low_rate_; + auto& ds = render_ds_; + auto& f = ffts_; + auto& s = spectra_; + const size_t num_bands = b.buffer[b.write].size(); + const size_t num_render_channels = b.buffer[b.write][0].size(); + RTC_DCHECK_EQ(block.size(), b.buffer[b.write].size()); + for (size_t band = 0; band < num_bands; ++band) { + RTC_DCHECK_EQ(block[band].size(), num_render_channels); + RTC_DCHECK_EQ(b.buffer[b.write][band].size(), num_render_channels); + for (size_t ch = 0; ch < num_render_channels; ++ch) { + RTC_DCHECK_EQ(block[band][ch].size(), b.buffer[b.write][band][ch].size()); + std::copy(block[band][ch].begin(), block[band][ch].end(), + b.buffer[b.write][band][ch].begin()); + } + } + + if (render_linear_amplitude_gain_ != 1.f) { + for (size_t band = 0; band < num_bands; ++band) { + for (size_t ch = 0; ch < num_render_channels; ++ch) { + for (size_t k = 0; k < 64; ++k) { + b.buffer[b.write][band][ch][k] *= render_linear_amplitude_gain_; + } + } + } + } + + std::array<float, kBlockSize> downmixed_render; + render_mixer_.ProduceOutput(b.buffer[b.write][0], downmixed_render); + render_decimator_.Decimate(downmixed_render, ds); + data_dumper_->DumpWav("aec3_render_decimator_output", ds.size(), ds.data(), + 16000 / down_sampling_factor_, 1); + std::copy(ds.rbegin(), ds.rend(), lr.buffer.begin() + lr.write); + for (size_t channel = 0; channel < b.buffer[b.write][0].size(); ++channel) { + fft_.PaddedFft(b.buffer[b.write][0][channel], + b.buffer[previous_write][0][channel], + &f.buffer[f.write][channel]); + f.buffer[f.write][channel].Spectrum(optimization_, + s.buffer[s.write][channel]); + } +} + +bool RenderDelayBufferImpl::DetectActiveRender( + rtc::ArrayView<const float> x) const { + const float x_energy = std::inner_product(x.begin(), x.end(), x.begin(), 0.f); + return x_energy > (config_.render_levels.active_render_limit * + config_.render_levels.active_render_limit) * + kFftLengthBy2; +} + +bool RenderDelayBufferImpl::DetectExcessRenderBlocks() { + bool excess_render_detected = false; + const size_t latency_blocks = static_cast<size_t>(BufferLatency()); + // The recently seen minimum latency in blocks. Should be close to 0. + min_latency_blocks_ = std::min(min_latency_blocks_, latency_blocks); + // After processing a configurable number of blocks the minimum latency is + // checked. + if (++excess_render_detection_counter_ >= + config_.buffering.excess_render_detection_interval_blocks) { + // If the minimum latency is not lower than the threshold there have been + // more render than capture frames. + excess_render_detected = min_latency_blocks_ > + config_.buffering.max_allowed_excess_render_blocks; + // Reset the counter and let the minimum latency be the current latency. + min_latency_blocks_ = latency_blocks; + excess_render_detection_counter_ = 0; + } + + data_dumper_->DumpRaw("aec3_latency_blocks", latency_blocks); + data_dumper_->DumpRaw("aec3_min_latency_blocks", min_latency_blocks_); + data_dumper_->DumpRaw("aec3_excess_render_detected", excess_render_detected); + return excess_render_detected; +} + +// Computes the latency in the buffer (the number of unread sub-blocks). +int RenderDelayBufferImpl::BufferLatency() const { + const DownsampledRenderBuffer& l = low_rate_; + int latency_samples = (l.buffer.size() + l.read - l.write) % l.buffer.size(); + int latency_blocks = latency_samples / sub_block_size_; + return latency_blocks; +} + +// Increments the write indices for the render buffers. +void RenderDelayBufferImpl::IncrementWriteIndices() { + low_rate_.UpdateWriteIndex(-sub_block_size_); + blocks_.IncWriteIndex(); + spectra_.DecWriteIndex(); + ffts_.DecWriteIndex(); +} + +// Increments the read indices of the low rate render buffers. +void RenderDelayBufferImpl::IncrementLowRateReadIndices() { + low_rate_.UpdateReadIndex(-sub_block_size_); +} + +// Increments the read indices for the render buffers. +void RenderDelayBufferImpl::IncrementReadIndices() { + if (blocks_.read != blocks_.write) { + blocks_.IncReadIndex(); + spectra_.DecReadIndex(); + ffts_.DecReadIndex(); + } +} + +// Checks for a render buffer overrun. +bool RenderDelayBufferImpl::RenderOverrun() { + return low_rate_.read == low_rate_.write || blocks_.read == blocks_.write; +} + +// Checks for a render buffer underrun. +bool RenderDelayBufferImpl::RenderUnderrun() { + return low_rate_.read == low_rate_.write; +} + +} // namespace + +RenderDelayBuffer* RenderDelayBuffer::Create(const EchoCanceller3Config& config, + int sample_rate_hz, + size_t num_render_channels) { + return new RenderDelayBufferImpl(config, sample_rate_hz, num_render_channels); +} + +} // namespace webrtc |