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AEC3: Redesign delay headroom

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This change reduces the risk of echo due to noise in the headroom
of the linear filter.

Changes:
- Use shorter delay headroom
- Delay headroom is specified in samples (not blocks)
- No hysteresis limit when delay is reduced

Bug: chromium:119942,webrtc:10341
Change-Id: I708e80e26d541dff8ca04b6da2d346a1d59cbfcb
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/126420
Commit-Queue: Gustaf Ullberg <gustaf@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Reviewed-by: Per Åhgren <peah@webrtc.org>
Reviewed-by: Jesus de Vicente Pena <devicentepena@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27126}
This commit is contained in:
Gustaf Ullberg
2019-03-14 11:24:54 +01:00
committed by Commit Bot
parent 41f9f2cc57
commit 9249fbf3a6
11 changed files with 48 additions and 72 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
modules/audio_processing/aec3/render_delay_controller.cc
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@ -46,9 +46,8 @@ class RenderDelayControllerImpl final : public RenderDelayController {
private:
static int instance_count_;
std::unique_ptr<ApmDataDumper> data_dumper_;
const int delay_headroom_blocks_;
const int hysteresis_limit_1_blocks_;
const int hysteresis_limit_2_blocks_;
const int hysteresis_limit_blocks_;
const int delay_headroom_samples_;
absl::optional<DelayEstimate> delay_;
EchoPathDelayEstimator delay_estimator_;
RenderDelayControllerMetrics metrics_;
@ -61,32 +60,22 @@ class RenderDelayControllerImpl final : public RenderDelayController {
DelayEstimate ComputeBufferDelay(
const absl::optional<DelayEstimate>& current_delay,
int delay_headroom_blocks,
int hysteresis_limit_1_blocks,
int hysteresis_limit_2_blocks,
int hysteresis_limit_blocks,
int delay_headroom_samples,
DelayEstimate estimated_delay) {
// The below division is not exact and the truncation is intended.
const int echo_path_delay_blocks = estimated_delay.delay >> kBlockSizeLog2;
// Subtract delay headroom.
const int delay_with_headroom_samples = std::max(
static_cast<int>(estimated_delay.delay) - delay_headroom_samples, 0);
// Compute the buffer delay increase required to achieve the desired latency.
size_t new_delay_blocks =
std::max(echo_path_delay_blocks - delay_headroom_blocks, 0);
size_t new_delay_blocks = delay_with_headroom_samples >> kBlockSizeLog2;
// Add hysteresis.
if (current_delay) {
size_t current_delay_blocks = current_delay->delay;
if (new_delay_blocks > current_delay_blocks) {
if (new_delay_blocks <=
current_delay_blocks + hysteresis_limit_1_blocks) {
new_delay_blocks = current_delay_blocks;
}
} else if (new_delay_blocks < current_delay_blocks) {
size_t hysteresis_limit = std::max(
static_cast<int>(current_delay_blocks) - hysteresis_limit_2_blocks,
0);
if (new_delay_blocks >= hysteresis_limit) {
new_delay_blocks = current_delay_blocks;
}
if (new_delay_blocks > current_delay_blocks &&
new_delay_blocks <= current_delay_blocks + hysteresis_limit_blocks) {
new_delay_blocks = current_delay_blocks;
}
}
@ -102,12 +91,9 @@ RenderDelayControllerImpl::RenderDelayControllerImpl(
int sample_rate_hz)
: data_dumper_(
new ApmDataDumper(rtc::AtomicOps::Increment(&instance_count_))),
delay_headroom_blocks_(
static_cast<int>(config.delay.delay_headroom_blocks)),
hysteresis_limit_1_blocks_(
static_cast<int>(config.delay.hysteresis_limit_1_blocks)),
hysteresis_limit_2_blocks_(
static_cast<int>(config.delay.hysteresis_limit_2_blocks)),
hysteresis_limit_blocks_(
static_cast<int>(config.delay.hysteresis_limit_blocks)),
delay_headroom_samples_(config.delay.delay_headroom_samples),
delay_estimator_(data_dumper_.get(), config),
last_delay_estimate_quality_(DelayEstimate::Quality::kCoarse) {
RTC_DCHECK(ValidFullBandRate(sample_rate_hz));
@ -177,10 +163,9 @@ absl::optional<DelayEstimate> RenderDelayControllerImpl::GetDelay(
const bool use_hysteresis =
last_delay_estimate_quality_ == DelayEstimate::Quality::kRefined &&
delay_samples_->quality == DelayEstimate::Quality::kRefined;
delay_ = ComputeBufferDelay(delay_, delay_headroom_blocks_,
use_hysteresis ? hysteresis_limit_1_blocks_ : 0,
use_hysteresis ? hysteresis_limit_2_blocks_ : 0,
*delay_samples_);
delay_ = ComputeBufferDelay(delay_,
use_hysteresis ? hysteresis_limit_blocks_ : 0,
delay_headroom_samples_, *delay_samples_);
last_delay_estimate_quality_ = delay_samples_->quality;
}