commit da5e9d04f59ed88d1db4a364ca23ac8466d7ec8b
author philipel <philipel@webrtc.org> Tue Jan 17 10:08:28 2017
committer Commit bot <commit-bot@chromium.org> Tue Jan 17 10:08:28 2017
tree dffae0b992d3581e0c2403c9c6b44a11a2a0b5d5
parent fa5a368b3cc9625153c6f10c30dbccd70e56357c

Initiate mid-call probing even if estimated bitrate is at max configured bitrate.

BUG=none

Review-Url: https://codereview.webrtc.org/2634883003
Cr-Commit-Position: refs/heads/master@{#16107}

webrtc/modules/congestion_controller/probe_controller.cc

diff --git a/webrtc/modules/congestion_controller/probe_controller.cc b/webrtc/modules/congestion_controller/probe_controller.cc
index e66f0ce..373b268 100644
--- a/webrtc/modules/congestion_controller/probe_controller.cc
+++ b/webrtc/modules/congestion_controller/probe_controller.cc
@@ -72,6 +72,8 @@
     start_bitrate_bps_ = min_bitrate_bps;
   }
 
+  // The reason we use the variable |old_max_bitrate_pbs| is because we
+  // need to set |max_bitrate_bps_| before we call InitiateProbing.
   int64_t old_max_bitrate_bps = max_bitrate_bps_;
   max_bitrate_bps_ = max_bitrate_bps;
 
@@ -85,10 +87,11 @@
       break;
 
     case State::kProbingComplete:
-      // Initiate probing when |max_bitrate_| was increased mid-call.
-      if (estimated_bitrate_bps_ != kExponentialProbingDisabled &&
-          estimated_bitrate_bps_ < old_max_bitrate_bps &&
-          max_bitrate_bps_ > old_max_bitrate_bps) {
+      // If the new max bitrate is higher than the old max bitrate and the
+      // estimate is lower than the new max bitrate then initiate probing.
+      if (estimated_bitrate_bps_ != 0 &&
+          old_max_bitrate_bps < max_bitrate_bps_ &&
+          estimated_bitrate_bps_ < max_bitrate_bps_) {
         // The assumption is that if we jump more than 20% in the bandwidth
         // estimate or if the bandwidth estimate is within 90% of the new
         // max bitrate then the probing attempt was successful.

webrtc/modules/congestion_controller/probe_controller_unittest.cc

diff --git a/webrtc/modules/congestion_controller/probe_controller_unittest.cc b/webrtc/modules/congestion_controller/probe_controller_unittest.cc
index fd6ecc1..19a9039 100644
--- a/webrtc/modules/congestion_controller/probe_controller_unittest.cc
+++ b/webrtc/modules/congestion_controller/probe_controller_unittest.cc
@@ -79,6 +79,21 @@
                                  kMaxBitrateBps + 100);
 }
 
+TEST_F(ProbeControllerTest, InitiatesProbingOnMaxBitrateIncreaseAtMaxBitrate) {
+  EXPECT_CALL(pacer_, CreateProbeCluster(_)).Times(AtLeast(2));
+  probe_controller_->SetBitrates(kMinBitrateBps, kStartBitrateBps,
+                                 kMaxBitrateBps);
+  // Long enough to time out exponential probing.
+  clock_.AdvanceTimeMilliseconds(kExponentialProbingTimeoutMs);
+  probe_controller_->SetEstimatedBitrate(kStartBitrateBps);
+  probe_controller_->Process();
+
+  probe_controller_->SetEstimatedBitrate(kMaxBitrateBps);
+  EXPECT_CALL(pacer_, CreateProbeCluster(kMaxBitrateBps + 100));
+  probe_controller_->SetBitrates(kMinBitrateBps, kStartBitrateBps,
+                                 kMaxBitrateBps + 100);
+}
+
 TEST_F(ProbeControllerTest, TestExponentialProbing) {
   probe_controller_->SetBitrates(kMinBitrateBps, kStartBitrateBps,
                                  kMaxBitrateBps);