commit 6ef59d1ced564efd9db76d6d2396c67eb0e65884
author Evan Shrubsole <eshr@google.com> Wed Jan 08 15:45:08 2020
committer Commit Bot <commit-bot@chromium.org> Wed Jan 15 11:21:14 2020
tree 3ae15acbb7d147fc96fd1a6dabbc8b2f2f346b33
parent 6dc06c8146d69901c45c57d0668d3734dfdab747

Don't pace audio by default

After experimentation, not pacing audio is better. This is controlled
by the field trial WebRTC-Pacer-BlockAudio. This change keeps the flag,
but changes the behaviour such that it defaults to Disabled. However,
audio can still be paced if one chooses by enabling the field trial.

Bug: webrtc:11257
Change-Id: I5b23a82bb6708c007cf8dfb40065c821eefdc4e3
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/165381
Commit-Queue: Evan Shrubsole <eshr@google.com>
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Reviewed-by: Christoffer Rodbro <crodbro@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30262}

modules/pacing/pacing_controller.cc

diff --git a/modules/pacing/pacing_controller.cc b/modules/pacing/pacing_controller.cc
index e346a83..e6dd7ac 100644
--- a/modules/pacing/pacing_controller.cc
+++ b/modules/pacing/pacing_controller.cc
@@ -96,7 +96,7 @@
           !IsDisabled(*field_trials_, "WebRTC-Pacer-DrainQueue")),
       send_padding_if_silent_(
           IsEnabled(*field_trials_, "WebRTC-Pacer-PadInSilence")),
-      pace_audio_(!IsDisabled(*field_trials_, "WebRTC-Pacer-BlockAudio")),
+      pace_audio_(IsEnabled(*field_trials_, "WebRTC-Pacer-BlockAudio")),
       small_first_probe_packet_(
           IsEnabled(*field_trials_, "WebRTC-Pacer-SmallFirstProbePacket")),
       send_side_bwe_with_overhead_(
@@ -600,7 +600,7 @@
   bool is_probe = pacing_info.probe_cluster_id != PacedPacketInfo::kNotAProbe;
   if (!unpaced_audio_packet && !is_probe) {
     if (Congested()) {
-      // Don't send anyting if congested.
+      // Don't send anything if congested.
       return nullptr;
     }
 

modules/pacing/pacing_controller_unittest.cc

diff --git a/modules/pacing/pacing_controller_unittest.cc b/modules/pacing/pacing_controller_unittest.cc
index e581e30..2e4e564 100644
--- a/modules/pacing/pacing_controller_unittest.cc
+++ b/modules/pacing/pacing_controller_unittest.cc
@@ -367,7 +367,8 @@
   pacer.ProcessPackets();
 }
 
-TEST_P(PacingControllerFieldTrialTest, DefaultCongestionWindowAffectsAudio) {
+TEST_P(PacingControllerFieldTrialTest, CongestionWindowAffectsAudioInTrial) {
+  ScopedFieldTrials trial("WebRTC-Pacer-BlockAudio/Enabled/");
   EXPECT_CALL(callback_, SendPadding).Times(0);
   PacingController pacer(&clock_, &callback_, nullptr, nullptr, GetParam());
   pacer.SetPacingRates(DataRate::kbps(10000), DataRate::Zero());
@@ -394,8 +395,7 @@
 }
 
 TEST_P(PacingControllerFieldTrialTest,
-       CongestionWindowDoesNotAffectAudioInTrial) {
-  ScopedFieldTrials trial("WebRTC-Pacer-BlockAudio/Disabled/");
+       DefaultCongestionWindowDoesNotAffectAudio) {
   EXPECT_CALL(callback_, SendPadding).Times(0);
   PacingController pacer(&clock_, &callback_, nullptr, nullptr, GetParam());
   pacer.SetPacingRates(DataRate::bps(10000000), DataRate::Zero());
@@ -411,7 +411,8 @@
   ProcessNext(&pacer);
 }
 
-TEST_P(PacingControllerFieldTrialTest, DefaultBudgetAffectsAudio) {
+TEST_P(PacingControllerFieldTrialTest, BudgetAffectsAudioInTrial) {
+  ScopedFieldTrials trial("WebRTC-Pacer-BlockAudio/Enabled/");
   PacingController pacer(&clock_, &callback_, nullptr, nullptr, GetParam());
   DataRate pacing_rate =
       DataRate::bps(video.packet_size / 3 * 8 * kProcessIntervalsPerSecond);
@@ -440,8 +441,7 @@
                 : PacingController::kMinSleepTime);
 }
 
-TEST_P(PacingControllerFieldTrialTest, BudgetDoesNotAffectAudioInTrial) {
-  ScopedFieldTrials trial("WebRTC-Pacer-BlockAudio/Disabled/");
+TEST_P(PacingControllerFieldTrialTest, DefaultBudgetDoesNotAffectAudio) {
   EXPECT_CALL(callback_, SendPadding).Times(0);
   PacingController pacer(&clock_, &callback_, nullptr, nullptr, GetParam());
   pacer.SetPacingRates(