From 4593047ee1531095c8870b5cc06c2fcd01d18a8b Mon Sep 17 00:00:00 2001
From: Ying Wang <yinwa@webrtc.org>
Date: Fri, 5 Feb 2021 11:07:00 +0100
Subject: [PATCH] Make congestion window pushback drop frame experiment config
 default.
MIME-Version: 1.0
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Bug: None
Change-Id: Ic3138b691cdf535e3d0e95ee6c1d63794414a1e3
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/204803
Commit-Queue: Ying Wang <yinwa@webrtc.org>
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33177}
---
 rtc_base/experiments/rate_control_settings.cc | 15 +++++++---
 rtc_base/experiments/rate_control_settings.h  |  2 +-
 .../rate_control_settings_unittest.cc         | 29 +++++++++++++++++--
 3 files changed, 38 insertions(+), 8 deletions(-)

diff --git a/rtc_base/experiments/rate_control_settings.cc b/rtc_base/experiments/rate_control_settings.cc
index 6766db62c3..bed194e683 100644
--- a/rtc_base/experiments/rate_control_settings.cc
+++ b/rtc_base/experiments/rate_control_settings.cc
@@ -24,10 +24,13 @@ namespace webrtc {
 
 namespace {
 
-const int kDefaultAcceptedQueueMs = 250;
+const int kDefaultAcceptedQueueMs = 350;
 
 const int kDefaultMinPushbackTargetBitrateBps = 30000;
 
+const char kCongestionWindowDefaultFieldTrialString[] =
+    "QueueSize:350,MinBitrate:30000,DropFrame:true";
+
 const char kUseBaseHeavyVp8Tl3RateAllocationFieldTrialName[] =
     "WebRTC-UseBaseHeavyVP8TL3RateAllocation";
 
@@ -91,9 +94,13 @@ std::unique_ptr<StructParametersParser> VideoRateControlConfig::Parser() {
 }
 
 RateControlSettings::RateControlSettings(
-    const WebRtcKeyValueConfig* const key_value_config)
-    : congestion_window_config_(CongestionWindowConfig::Parse(
-          key_value_config->Lookup(CongestionWindowConfig::kKey))) {
+    const WebRtcKeyValueConfig* const key_value_config) {
+  std::string congestion_window_config =
+      key_value_config->Lookup(CongestionWindowConfig::kKey).empty()
+          ? kCongestionWindowDefaultFieldTrialString
+          : key_value_config->Lookup(CongestionWindowConfig::kKey);
+  congestion_window_config_ =
+      CongestionWindowConfig::Parse(congestion_window_config);
   video_config_.vp8_base_heavy_tl3_alloc = IsEnabled(
       key_value_config, kUseBaseHeavyVp8Tl3RateAllocationFieldTrialName);
   ParseHysteresisFactor(key_value_config, kVideoHysteresisFieldTrialname,
diff --git a/rtc_base/experiments/rate_control_settings.h b/rtc_base/experiments/rate_control_settings.h
index db7f1cd136..1c38e927dc 100644
--- a/rtc_base/experiments/rate_control_settings.h
+++ b/rtc_base/experiments/rate_control_settings.h
@@ -96,7 +96,7 @@ class RateControlSettings final {
   explicit RateControlSettings(
       const WebRtcKeyValueConfig* const key_value_config);
 
-  const CongestionWindowConfig congestion_window_config_;
+  CongestionWindowConfig congestion_window_config_;
   VideoRateControlConfig video_config_;
 };
 
diff --git a/rtc_base/experiments/rate_control_settings_unittest.cc b/rtc_base/experiments/rate_control_settings_unittest.cc
index 8d722722e4..84e5825224 100644
--- a/rtc_base/experiments/rate_control_settings_unittest.cc
+++ b/rtc_base/experiments/rate_control_settings_unittest.cc
@@ -20,7 +20,7 @@ namespace webrtc {
 namespace {
 
 TEST(RateControlSettingsTest, CongestionWindow) {
-  EXPECT_FALSE(
+  EXPECT_TRUE(
       RateControlSettings::ParseFromFieldTrials().UseCongestionWindow());
 
   test::ScopedFieldTrials field_trials(
@@ -32,8 +32,8 @@ TEST(RateControlSettingsTest, CongestionWindow) {
 }
 
 TEST(RateControlSettingsTest, CongestionWindowPushback) {
-  EXPECT_FALSE(RateControlSettings::ParseFromFieldTrials()
-                   .UseCongestionWindowPushback());
+  EXPECT_TRUE(RateControlSettings::ParseFromFieldTrials()
+                  .UseCongestionWindowPushback());
 
   test::ScopedFieldTrials field_trials(
       "WebRTC-CongestionWindow/QueueSize:100,MinBitrate:100000/");
@@ -44,6 +44,29 @@ TEST(RateControlSettingsTest, CongestionWindowPushback) {
             100000u);
 }
 
+TEST(RateControlSettingsTest, CongestionWindowPushbackDropframe) {
+  EXPECT_TRUE(RateControlSettings::ParseFromFieldTrials()
+                  .UseCongestionWindowPushback());
+
+  test::ScopedFieldTrials field_trials(
+      "WebRTC-CongestionWindow/"
+      "QueueSize:100,MinBitrate:100000,DropFrame:true/");
+  const RateControlSettings settings_after =
+      RateControlSettings::ParseFromFieldTrials();
+  EXPECT_TRUE(settings_after.UseCongestionWindowPushback());
+  EXPECT_EQ(settings_after.CongestionWindowMinPushbackTargetBitrateBps(),
+            100000u);
+  EXPECT_TRUE(settings_after.UseCongestionWindowDropFrameOnly());
+}
+
+TEST(RateControlSettingsTest, CongestionWindowPushbackDefaultConfig) {
+  const RateControlSettings settings =
+      RateControlSettings::ParseFromFieldTrials();
+  EXPECT_TRUE(settings.UseCongestionWindowPushback());
+  EXPECT_EQ(settings.CongestionWindowMinPushbackTargetBitrateBps(), 30000u);
+  EXPECT_TRUE(settings.UseCongestionWindowDropFrameOnly());
+}
+
 TEST(RateControlSettingsTest, PacingFactor) {
   EXPECT_FALSE(RateControlSettings::ParseFromFieldTrials().GetPacingFactor());