Remove unused field trial WebRTC-JitterUpperBound

Bug: webrtc:9898
Change-Id: I89f2baca9b96fc00fc73d24086e7c6f5ed8307a8
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/269401
Reviewed-by: Emil Lundmark <lndmrk@webrtc.org>
Auto-Submit: Erik Språng <sprang@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37620}

modules/video_coding/BUILD.gn

@@ -253,7 +253,6 @@ rtc_library("video_coding") {
     "../../rtc_base:timeutils",
     "../../rtc_base/experiments:alr_experiment",
     "../../rtc_base/experiments:field_trial_parser",
-    "../../rtc_base/experiments:jitter_upper_bound_experiment",
     "../../rtc_base/experiments:min_video_bitrate_experiment",
     "../../rtc_base/experiments:rate_control_settings",
     "../../rtc_base/experiments:rtt_mult_experiment",
@@ -1195,7 +1194,6 @@ if (rtc_include_tests) {
       "../../rtc_base:task_queue_for_test",
       "../../rtc_base:timeutils",
       "../../rtc_base/experiments:encoder_info_settings",
-      "../../rtc_base/experiments:jitter_upper_bound_experiment",
       "../../rtc_base/synchronization:mutex",
       "../../rtc_base/system:unused",
       "../../system_wrappers",

modules/video_coding/timing/BUILD.gn

@@ -44,7 +44,6 @@ rtc_library("jitter_estimator") {
     "../../../api/units:timestamp",
     "../../../rtc_base",
     "../../../rtc_base:safe_conversions",
-    "../../../rtc_base/experiments:jitter_upper_bound_experiment",
     "../../../system_wrappers",
   ]
   absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
@@ -105,7 +104,6 @@ rtc_library("timing_unittests") {
     "../../../rtc_base:histogram_percentile_counter",
     "../../../rtc_base:stringutils",
     "../../../rtc_base:timeutils",
-    "../../../rtc_base/experiments:jitter_upper_bound_experiment",
     "../../../system_wrappers:system_wrappers",
     "../../../test:scoped_key_value_config",
     "../../../test:test_support",

modules/video_coding/timing/jitter_estimator.cc

@@ -23,7 +23,6 @@
 #include "api/units/time_delta.h"
 #include "api/units/timestamp.h"
 #include "modules/video_coding/timing/rtt_filter.h"
-#include "rtc_base/experiments/jitter_upper_bound_experiment.h"
 #include "rtc_base/numerics/safe_conversions.h"
 #include "system_wrappers/include/clock.h"
 
@@ -53,9 +52,6 @@ JitterEstimator::JitterEstimator(Clock* clock,
                                  const FieldTrialsView& field_trials)
     : fps_counter_(30),  // TODO(sprang): Use an estimator with limit based on
                          // time, rather than number of samples.
-      time_deviation_upper_bound_(
-          JitterUpperBoundExperiment::GetUpperBoundSigmas().value_or(
-              kDefaultMaxTimestampDeviationInSigmas)),
       enable_reduced_delay_(
           !field_trials.IsEnabled("WebRTC-ReducedJitterDelayKillSwitch")),
       clock_(clock) {
@@ -133,8 +129,8 @@ void JitterEstimator::UpdateEstimate(TimeDelta frame_delay,
   prev_frame_size_ = frame_size;
 
   // Cap frame_delay based on the current time deviation noise.
-  TimeDelta max_time_deviation =
+  TimeDelta max_time_deviation = TimeDelta::Millis(
-      TimeDelta::Millis(time_deviation_upper_bound_ * sqrt(var_noise_) + 0.5);
+      kDefaultMaxTimestampDeviationInSigmas * sqrt(var_noise_) + 0.5);
   frame_delay.Clamp(-max_time_deviation, max_time_deviation);
 
   // Only update the Kalman filter if the sample is not considered an extreme

modules/video_coding/timing/jitter_estimator.h

@@ -148,7 +148,6 @@ class JitterEstimator {
 
   // Tracks frame rates in microseconds.
   rtc::RollingAccumulator<uint64_t> fps_counter_;
-  const double time_deviation_upper_bound_;
   const bool enable_reduced_delay_;
   Clock* clock_;
 };

modules/video_coding/timing/jitter_estimator_unittest.cc

@@ -12,6 +12,7 @@
 #include <stdint.h>
 
 #include <memory>
+#include <utility>
 #include <vector>
 
 #include "absl/types/optional.h"
@@ -19,7 +20,6 @@
 #include "api/units/data_size.h"
 #include "api/units/frequency.h"
 #include "api/units/time_delta.h"
-#include "rtc_base/experiments/jitter_upper_bound_experiment.h"
 #include "rtc_base/numerics/histogram_percentile_counter.h"
 #include "rtc_base/strings/string_builder.h"
 #include "rtc_base/time_utils.h"
@@ -96,45 +96,15 @@ TEST_F(TestJitterEstimator, TestLowRateDisabled) {
   }
 }
 
-TEST_F(TestJitterEstimator, TestUpperBound) {
+TEST_F(TestJitterEstimator, RttMultAddCap) {
-  struct TestContext {
+  std::vector<std::pair<TimeDelta, rtc::HistogramPercentileCounter>>
-    TestContext()
+      jitter_by_rtt_mult_cap;
-        : upper_bound(0.0),
+  jitter_by_rtt_mult_cap.emplace_back(
-          rtt_mult(0),
+      /*rtt_mult_add_cap=*/TimeDelta::Millis(10), /*long_tail_boundary=*/1000);
-          rtt_mult_add_cap_ms(absl::nullopt),
+  jitter_by_rtt_mult_cap.emplace_back(
-          percentiles(1000) {}
+      /*rtt_mult_add_cap=*/TimeDelta::Millis(200), /*long_tail_boundary=*/1000);
-    double upper_bound;
-    double rtt_mult;
-    absl::optional<TimeDelta> rtt_mult_add_cap_ms;
-    rtc::HistogramPercentileCounter percentiles;
-  };
-  std::vector<TestContext> test_cases(4);
 
-  // Large upper bound, rtt_mult = 0, and nullopt for rtt_mult addition cap.
+  for (auto& [rtt_mult_add_cap, jitter] : jitter_by_rtt_mult_cap) {
-  test_cases[0].upper_bound = 100.0;
-  test_cases[0].rtt_mult = 0;
-  test_cases[0].rtt_mult_add_cap_ms = absl::nullopt;
-  // Small upper bound, rtt_mult = 0, and nullopt for rtt_mult addition cap.
-  test_cases[1].upper_bound = 3.5;
-  test_cases[1].rtt_mult = 0;
-  test_cases[1].rtt_mult_add_cap_ms = absl::nullopt;
-  // Large upper bound, rtt_mult = 1, and large rtt_mult addition cap value.
-  test_cases[2].upper_bound = 1000.0;
-  test_cases[2].rtt_mult = 1.0;
-  test_cases[2].rtt_mult_add_cap_ms = TimeDelta::Millis(200);
-  // Large upper bound, rtt_mult = 1, and small rtt_mult addition cap value.
-  test_cases[3].upper_bound = 1000.0;
-  test_cases[3].rtt_mult = 1.0;
-  test_cases[3].rtt_mult_add_cap_ms = TimeDelta::Millis(10);
-
-  // Test jitter buffer upper_bound and rtt_mult addition cap sizes.
-  for (TestContext& context : test_cases) {
-    // Set up field trial and reset jitter estimator.
-    char string_buf[64];
-    rtc::SimpleStringBuilder ssb(string_buf);
-    ssb << JitterUpperBoundExperiment::kJitterUpperBoundExperimentName
-        << "/Enabled-" << context.upper_bound << "/";
-    test::ScopedKeyValueConfig field_trials(field_trials_, ssb.str());
     SetUp();
 
     ValueGenerator gen(50);
@@ -143,30 +113,18 @@ TEST_F(TestJitterEstimator, TestUpperBound) {
     for (int i = 0; i < 100; ++i) {
       estimator_->UpdateEstimate(gen.Delay(), gen.FrameSize());
       fake_clock_.AdvanceTime(time_delta);
-      estimator_->FrameNacked();    // To test rtt_mult.
+      estimator_->FrameNacked();
-      estimator_->UpdateRtt(kRtt);  // To test rtt_mult.
+      estimator_->UpdateRtt(kRtt);
-      context.percentiles.Add(
+      jitter.Add(
-          estimator_
+          estimator_->GetJitterEstimate(/*rtt_mult=*/1.0, rtt_mult_add_cap)
-              ->GetJitterEstimate(context.rtt_mult, context.rtt_mult_add_cap_ms)
               .ms());
       gen.Advance();
     }
   }
 
-  // Median should be similar after three seconds. Allow 5% error margin.
+  // 200ms cap should result in at least 25% higher max compared to 10ms.
-  uint32_t median_unbound = *test_cases[0].percentiles.GetPercentile(0.5);
+  EXPECT_GT(*jitter_by_rtt_mult_cap[1].second.GetPercentile(1.0),
-  uint32_t median_bounded = *test_cases[1].percentiles.GetPercentile(0.5);
+            *jitter_by_rtt_mult_cap[0].second.GetPercentile(1.0) * 1.25);
-  EXPECT_NEAR(median_unbound, median_bounded, (median_unbound * 5) / 100);
-
-  // Max should be lower for the bounded case.
-  uint32_t max_unbound = *test_cases[0].percentiles.GetPercentile(1.0);
-  uint32_t max_bounded = *test_cases[1].percentiles.GetPercentile(1.0);
-  EXPECT_GT(max_unbound, static_cast<uint32_t>(max_bounded * 1.25));
-
-  // With rtt_mult = 1, max should be lower with small rtt_mult add cap value.
-  max_unbound = *test_cases[2].percentiles.GetPercentile(1.0);
-  max_bounded = *test_cases[3].percentiles.GetPercentile(1.0);
-  EXPECT_GT(max_unbound, static_cast<uint32_t>(max_bounded * 1.25));
 }
 
 }  // namespace webrtc

rtc_base/experiments/BUILD.gn

@@ -178,18 +178,6 @@ rtc_library("rtt_mult_experiment") {
   absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
 }
 
-rtc_library("jitter_upper_bound_experiment") {
-  sources = [
-    "jitter_upper_bound_experiment.cc",
-    "jitter_upper_bound_experiment.h",
-  ]
-  deps = [
-    "..:logging",
-    "../../system_wrappers:field_trial",
-  ]
-  absl_deps = [ "//third_party/abseil-cpp/absl/types:optional" ]
-}
-
 rtc_library("rate_control_settings") {
   sources = [
     "rate_control_settings.cc",

rtc_base/experiments/OWNERS

@@ -2,15 +2,12 @@ asapersson@webrtc.org
 sprang@webrtc.org
 srte@webrtc.org
 
-per-file alr_experiment*=sprang@webrtc.org
 per-file audio_allocation_settings*=srte@webrtc.org
 per-file congestion_controller_experiment*=srte@webrtc.org
 per-file cpu_speed_experiment*=asapersson@webrtc.org
 per-file field_trial*=srte@webrtc.org
-per-file jitter_upper_bound_experiment*=sprang@webrtc.org
 per-file keyframe_interval_settings*=brandtr@webrtc.org
 per-file normalize_simulcast_size_experiment*=asapersson@webrtc.org
 per-file quality_scaling_experiment*=asapersson@webrtc.org
 per-file rtt_mult_experiment*=mhoro@webrtc.org
-per-file rate_control_settings*=sprang@webrtc.org
 per-file rate_control_settings*=srte@webrtc.org

rtc_base/experiments/jitter_upper_bound_experiment.cc

@@ -1,47 +0,0 @@
-/*
- *  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 "rtc_base/experiments/jitter_upper_bound_experiment.h"
-
-#include <stdio.h>
-
-#include <string>
-
-#include "rtc_base/logging.h"
-#include "system_wrappers/include/field_trial.h"
-
-namespace webrtc {
-
-const char JitterUpperBoundExperiment::kJitterUpperBoundExperimentName[] =
-    "WebRTC-JitterUpperBound";
-
-absl::optional<double> JitterUpperBoundExperiment::GetUpperBoundSigmas() {
-  if (!field_trial::IsEnabled(kJitterUpperBoundExperimentName)) {
-    return absl::nullopt;
-  }
-  const std::string group =
-      webrtc::field_trial::FindFullName(kJitterUpperBoundExperimentName);
-
-  double upper_bound_sigmas;
-  if (sscanf(group.c_str(), "Enabled-%lf", &upper_bound_sigmas) != 1) {
-    RTC_LOG(LS_WARNING) << "Invalid number of parameters provided.";
-    return absl::nullopt;
-  }
-
-  if (upper_bound_sigmas < 0) {
-    RTC_LOG(LS_WARNING) << "Invalid jitter upper bound sigmas, must be >= 0.0: "
-                        << upper_bound_sigmas;
-    return absl::nullopt;
-  }
-
-  return upper_bound_sigmas;
-}
-
-}  // namespace webrtc

rtc_base/experiments/jitter_upper_bound_experiment.h

@@ -1,31 +0,0 @@
-/*
- *  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.
- */
-
-#ifndef RTC_BASE_EXPERIMENTS_JITTER_UPPER_BOUND_EXPERIMENT_H_
-#define RTC_BASE_EXPERIMENTS_JITTER_UPPER_BOUND_EXPERIMENT_H_
-
-#include "absl/types/optional.h"
-
-namespace webrtc {
-
-class JitterUpperBoundExperiment {
- public:
-  // Returns nullopt if experiment is not on, otherwise returns the configured
-  // upper bound for frame delay delta used in jitter estimation, expressed as
-  // number of standard deviations of the current deviation from the expected
-  // delay.
-  static absl::optional<double> GetUpperBoundSigmas();
-
-  static const char kJitterUpperBoundExperimentName[];
-};
-
-}  // namespace webrtc
-
-#endif  // RTC_BASE_EXPERIMENTS_JITTER_UPPER_BOUND_EXPERIMENT_H_