Refactor delay manager.
Split out `RelativeArrivalDelayTracker` and `DelayOptimizer` logic.
This is in preparation for adding another `DelayOptimizer` specialized in handling reordered packets.
Bug: webrtc:10178
Change-Id: Id3c1746d91980b171fa524f9b2b71cf11fc75f64
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/231224
Commit-Queue: Jakob Ivarsson <jakobi@webrtc.org>
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#34938}
diff --git a/modules/audio_coding/neteq/delay_manager.cc b/modules/audio_coding/neteq/delay_manager.cc
index c250977..9f7eebd 100644
--- a/modules/audio_coding/neteq/delay_manager.cc
+++ b/modules/audio_coding/neteq/delay_manager.cc
@@ -18,10 +18,8 @@
#include <numeric>
#include <string>
-#include "modules/audio_coding/neteq/histogram.h"
#include "modules/include/module_common_types_public.h"
#include "rtc_base/checks.h"
-#include "rtc_base/experiments/struct_parameters_parser.h"
#include "rtc_base/logging.h"
#include "rtc_base/numerics/safe_conversions.h"
#include "rtc_base/numerics/safe_minmax.h"
@@ -32,157 +30,94 @@
constexpr int kMinBaseMinimumDelayMs = 0;
constexpr int kMaxBaseMinimumDelayMs = 10000;
-constexpr int kDelayBuckets = 100;
-constexpr int kBucketSizeMs = 20;
constexpr int kStartDelayMs = 80;
-struct DelayManagerConfig {
- double quantile = 0.97;
- double forget_factor = 0.9993;
- absl::optional<double> start_forget_weight = 2;
- absl::optional<int> resample_interval_ms;
- int max_history_ms = 2000;
-
- std::unique_ptr<webrtc::StructParametersParser> Parser() {
- return webrtc::StructParametersParser::Create( //
- "quantile", &quantile, //
- "forget_factor", &forget_factor, //
- "start_forget_weight", &start_forget_weight, //
- "resample_interval_ms", &resample_interval_ms, //
- "max_history_ms", &max_history_ms);
- }
-
- // TODO(jakobi): remove legacy field trial.
- void MaybeUpdateFromLegacyFieldTrial() {
- constexpr char kDelayHistogramFieldTrial[] =
- "WebRTC-Audio-NetEqDelayHistogram";
- if (!webrtc::field_trial::IsEnabled(kDelayHistogramFieldTrial)) {
- return;
- }
- const auto field_trial_string =
- webrtc::field_trial::FindFullName(kDelayHistogramFieldTrial);
- double percentile = -1.0;
- double forget_factor = -1.0;
- double start_forget_weight = -1.0;
- if (sscanf(field_trial_string.c_str(), "Enabled-%lf-%lf-%lf", &percentile,
- &forget_factor, &start_forget_weight) >= 2 &&
- percentile >= 0.0 && percentile <= 100.0 && forget_factor >= 0.0 &&
- forget_factor <= 1.0) {
- this->quantile = percentile / 100;
- this->forget_factor = forget_factor;
- this->start_forget_weight = start_forget_weight >= 1
- ? absl::make_optional(start_forget_weight)
- : absl::nullopt;
- }
- }
-
- explicit DelayManagerConfig() {
- Parser()->Parse(webrtc::field_trial::FindFullName(
- "WebRTC-Audio-NetEqDelayManagerConfig"));
- MaybeUpdateFromLegacyFieldTrial();
- RTC_LOG(LS_INFO) << "Delay manager config:"
- " quantile="
- << quantile << " forget_factor=" << forget_factor
- << " start_forget_weight="
- << start_forget_weight.value_or(0)
- << " resample_interval_ms="
- << resample_interval_ms.value_or(0)
- << " max_history_ms=" << max_history_ms;
- }
-};
-
} // namespace
-DelayManager::DelayManager(int max_packets_in_buffer,
- int base_minimum_delay_ms,
- int histogram_quantile,
- absl::optional<int> resample_interval_ms,
- int max_history_ms,
- const TickTimer* tick_timer,
- std::unique_ptr<Histogram> histogram)
- : max_packets_in_buffer_(max_packets_in_buffer),
- histogram_(std::move(histogram)),
- histogram_quantile_(histogram_quantile),
- tick_timer_(tick_timer),
- resample_interval_ms_(resample_interval_ms),
- max_history_ms_(max_history_ms),
- base_minimum_delay_ms_(base_minimum_delay_ms),
- effective_minimum_delay_ms_(base_minimum_delay_ms),
+DelayManager::Config::Config() {
+ Parser()->Parse(webrtc::field_trial::FindFullName(
+ "WebRTC-Audio-NetEqDelayManagerConfig"));
+ MaybeUpdateFromLegacyFieldTrial();
+}
+
+void DelayManager::Config::Log() {
+ RTC_LOG(LS_INFO) << "Delay manager config:"
+ " quantile="
+ << quantile << " forget_factor=" << forget_factor
+ << " start_forget_weight=" << start_forget_weight.value_or(0)
+ << " resample_interval_ms="
+ << resample_interval_ms.value_or(0)
+ << " max_history_ms=" << max_history_ms;
+}
+
+std::unique_ptr<StructParametersParser> DelayManager::Config::Parser() {
+ return StructParametersParser::Create( //
+ "quantile", &quantile, //
+ "forget_factor", &forget_factor, //
+ "start_forget_weight", &start_forget_weight, //
+ "resample_interval_ms", &resample_interval_ms, //
+ "max_history_ms", &max_history_ms);
+}
+
+// TODO(jakobi): remove legacy field trial.
+void DelayManager::Config::MaybeUpdateFromLegacyFieldTrial() {
+ constexpr char kDelayHistogramFieldTrial[] =
+ "WebRTC-Audio-NetEqDelayHistogram";
+ if (!webrtc::field_trial::IsEnabled(kDelayHistogramFieldTrial)) {
+ return;
+ }
+ const auto field_trial_string =
+ webrtc::field_trial::FindFullName(kDelayHistogramFieldTrial);
+ double percentile = -1.0;
+ double forget_factor = -1.0;
+ double start_forget_weight = -1.0;
+ if (sscanf(field_trial_string.c_str(), "Enabled-%lf-%lf-%lf", &percentile,
+ &forget_factor, &start_forget_weight) >= 2 &&
+ percentile >= 0.0 && percentile <= 100.0 && forget_factor >= 0.0 &&
+ forget_factor <= 1.0) {
+ this->quantile = percentile / 100;
+ this->forget_factor = forget_factor;
+ this->start_forget_weight = start_forget_weight >= 1
+ ? absl::make_optional(start_forget_weight)
+ : absl::nullopt;
+ }
+}
+
+DelayManager::DelayManager(const Config& config, const TickTimer* tick_timer)
+ : max_packets_in_buffer_(config.max_packets_in_buffer),
+ underrun_optimizer_(tick_timer,
+ (1 << 30) * config.quantile,
+ (1 << 15) * config.forget_factor,
+ config.start_forget_weight,
+ config.resample_interval_ms),
+ relative_arrival_delay_tracker_(tick_timer, config.max_history_ms),
+ base_minimum_delay_ms_(config.base_minimum_delay_ms),
+ effective_minimum_delay_ms_(config.base_minimum_delay_ms),
minimum_delay_ms_(0),
maximum_delay_ms_(0),
target_level_ms_(kStartDelayMs) {
- RTC_CHECK(histogram_);
RTC_DCHECK_GE(base_minimum_delay_ms_, 0);
Reset();
}
-std::unique_ptr<DelayManager> DelayManager::Create(
- int max_packets_in_buffer,
- int base_minimum_delay_ms,
- const TickTimer* tick_timer) {
- DelayManagerConfig config;
- int forget_factor_q15 = (1 << 15) * config.forget_factor;
- int quantile_q30 = (1 << 30) * config.quantile;
- std::unique_ptr<Histogram> histogram = std::make_unique<Histogram>(
- kDelayBuckets, forget_factor_q15, config.start_forget_weight);
- return std::make_unique<DelayManager>(
- max_packets_in_buffer, base_minimum_delay_ms, quantile_q30,
- config.resample_interval_ms, config.max_history_ms, tick_timer,
- std::move(histogram));
-}
-
DelayManager::~DelayManager() {}
absl::optional<int> DelayManager::Update(uint32_t timestamp,
int sample_rate_hz,
bool reset) {
- if (sample_rate_hz <= 0) {
+ if (reset) {
+ relative_arrival_delay_tracker_.Reset();
+ }
+ absl::optional<int> relative_delay =
+ relative_arrival_delay_tracker_.Update(timestamp, sample_rate_hz);
+ if (!relative_delay) {
return absl::nullopt;
}
- if (!last_timestamp_ || reset) {
- // Restart relative delay esimation from this packet.
- delay_history_.clear();
- packet_iat_stopwatch_ = tick_timer_->GetNewStopwatch();
- last_timestamp_ = timestamp;
- resample_stopwatch_ = tick_timer_->GetNewStopwatch();
- max_delay_in_interval_ms_ = 0;
- return absl::nullopt;
- }
-
- const int expected_iat_ms =
- 1000ll * static_cast<int32_t>(timestamp - *last_timestamp_) /
- sample_rate_hz;
- const int iat_ms = packet_iat_stopwatch_->ElapsedMs();
- const int iat_delay_ms = iat_ms - expected_iat_ms;
- UpdateDelayHistory(iat_delay_ms, timestamp, sample_rate_hz);
- int relative_delay = CalculateRelativePacketArrivalDelay();
-
- absl::optional<int> histogram_update;
- if (resample_interval_ms_) {
- if (static_cast<int>(resample_stopwatch_->ElapsedMs()) >
- *resample_interval_ms_) {
- histogram_update = max_delay_in_interval_ms_;
- resample_stopwatch_ = tick_timer_->GetNewStopwatch();
- max_delay_in_interval_ms_ = 0;
- }
- max_delay_in_interval_ms_ =
- std::max(max_delay_in_interval_ms_, relative_delay);
- } else {
- histogram_update = relative_delay;
- }
- if (histogram_update) {
- const int index = *histogram_update / kBucketSizeMs;
- if (index < histogram_->NumBuckets()) {
- // Maximum delay to register is 2000 ms.
- histogram_->Add(index);
- }
- }
-
- // Calculate new `target_level_ms_` based on updated statistics.
- int bucket_index = histogram_->Quantile(histogram_quantile_);
- target_level_ms_ = (1 + bucket_index) * kBucketSizeMs;
+ underrun_optimizer_.Update(*relative_delay);
+ target_level_ms_ =
+ underrun_optimizer_.GetOptimalDelayMs().value_or(kStartDelayMs);
target_level_ms_ = std::max(target_level_ms_, effective_minimum_delay_ms_);
if (maximum_delay_ms_ > 0) {
target_level_ms_ = std::min(target_level_ms_, maximum_delay_ms_);
@@ -195,37 +130,9 @@
target_level_ms_, 3 * max_packets_in_buffer_ * packet_len_ms_ / 4);
}
- // Prepare for next packet arrival.
- packet_iat_stopwatch_ = tick_timer_->GetNewStopwatch();
- last_timestamp_ = timestamp;
return relative_delay;
}
-void DelayManager::UpdateDelayHistory(int iat_delay_ms,
- uint32_t timestamp,
- int sample_rate_hz) {
- PacketDelay delay;
- delay.iat_delay_ms = iat_delay_ms;
- delay.timestamp = timestamp;
- delay_history_.push_back(delay);
- while (static_cast<int32_t>(timestamp - delay_history_.front().timestamp) >
- max_history_ms_ * sample_rate_hz / 1000) {
- delay_history_.pop_front();
- }
-}
-
-int DelayManager::CalculateRelativePacketArrivalDelay() const {
- // This effectively calculates arrival delay of a packet relative to the
- // packet preceding the history window. If the arrival delay ever becomes
- // smaller than zero, it means the reference packet is invalid, and we
- // move the reference.
- int relative_delay = 0;
- for (const PacketDelay& delay : delay_history_) {
- relative_delay += delay.iat_delay_ms;
- relative_delay = std::max(relative_delay, 0);
- }
- return relative_delay;
-}
int DelayManager::SetPacketAudioLength(int length_ms) {
if (length_ms <= 0) {
@@ -238,13 +145,9 @@
void DelayManager::Reset() {
packet_len_ms_ = 0;
- histogram_->Reset();
- delay_history_.clear();
+ underrun_optimizer_.Reset();
+ relative_arrival_delay_tracker_.Reset();
target_level_ms_ = kStartDelayMs;
- packet_iat_stopwatch_ = tick_timer_->GetNewStopwatch();
- last_timestamp_ = absl::nullopt;
- resample_stopwatch_ = tick_timer_->GetNewStopwatch();
- max_delay_in_interval_ms_ = 0;
}
int DelayManager::TargetDelayMs() const {