Update the BWE when the network route changes.

webrtc/modules/congestion_controller/congestion_controller.cc

Index: webrtc/modules/congestion_controller/congestion_controller.cc
diff --git a/webrtc/modules/congestion_controller/congestion_controller.cc b/webrtc/modules/congestion_controller/congestion_controller.cc
index 5767448a5f7bf711a24ef214ea47d5f5cac18f20..ca3d4ccbbc0bdea45d58588e0db9bc73df8a369d 100644
--- a/webrtc/modules/congestion_controller/congestion_controller.cc
+++ b/webrtc/modules/congestion_controller/congestion_controller.cc
@@ -212,21 +212,25 @@ void CongestionController::Init() {
       min_bitrate_bps_);
 }
 
-
-void CongestionController::SetBweBitrates(int min_bitrate_bps,
-                                          int start_bitrate_bps,
-                                          int max_bitrate_bps) {
+void CongestionController::FixBitrates(int* bitrate_bps,

[stefan-webrtc, 2016/05/27 21:46:15]

ClampBitrates

[honghaiz3, 2016/05/27 23:20:44]

Done.

+                                       int* min_bitrate_bps,
+                                       int* max_bitrate_bps) {
   // TODO(holmer): We should make sure the default bitrates are set to 10 kbps,
   // and that we don't try to set the min bitrate to 0 from any applications.
   // The congestion controller should allow a min bitrate of 0.
   const int kMinBitrateBps = 10000;
-  if (min_bitrate_bps < kMinBitrateBps)
-    min_bitrate_bps = kMinBitrateBps;
-  if (max_bitrate_bps > 0)
-    max_bitrate_bps = std::max(min_bitrate_bps, max_bitrate_bps);
-  if (start_bitrate_bps > 0)
-    start_bitrate_bps = std::max(min_bitrate_bps, start_bitrate_bps);
+  if (*min_bitrate_bps < kMinBitrateBps)
+    *min_bitrate_bps = kMinBitrateBps;
+  if (*max_bitrate_bps > 0)
+    *max_bitrate_bps = std::max(*min_bitrate_bps, *max_bitrate_bps);
+  if (*bitrate_bps > 0)
+    *bitrate_bps = std::max(*min_bitrate_bps, *bitrate_bps);
+}
 
+void CongestionController::SetBweBitrates(int min_bitrate_bps,
+                                          int start_bitrate_bps,
+                                          int max_bitrate_bps) {
+  FixBitrates(&start_bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
   bitrate_controller_->SetBitrates(start_bitrate_bps,
                                    min_bitrate_bps,
                                    max_bitrate_bps);
@@ -239,6 +243,15 @@ void CongestionController::SetBweBitrates(int min_bitrate_bps,
   MaybeTriggerOnNetworkChanged();
 }
 
+void CongestionController::ResetBweBitrates(int bitrate_bps,

[stefan-webrtc, 2016/05/27 21:46:15]

Is this called only on the send-side, or both send-side and receive-side? Maybe
we should also reset remote_bitrate_estimator_ in case of both sides.

[honghaiz3, 2016/05/27 23:20:44]

Are we using the send-side BWE? Do we still need the receive-side one?
Is it just resetting the min bitrate of the remb? Added that if yes.

[stefan-webrtc, 2016/05/30 06:47:03]

Receive-side BWE may still be negotiated instead of send-side, at least for the
foreseeable future.

[honghaiz3, 2016/06/01 16:54:10]

Acknowledged.

+                                            int min_bitrate_bps,
+                                            int max_bitrate_bps) {
+  FixBitrates(&bitrate_bps, &min_bitrate_bps, &max_bitrate_bps);
+  bitrate_controller_->ResetBitrates(bitrate_bps, min_bitrate_bps,

[stefan-webrtc, 2016/05/27 21:46:15]

Seems incorrect to me that we don't also reset
transport_feedback_adapter_.GetBitrateEstimator(). If we reset BWE we should
reset both the delay based and the loss based.

[honghaiz3, 2016/05/27 23:20:44]

Done.

+                                     max_bitrate_bps);
+  MaybeTriggerOnNetworkChanged();
+}
+
 BitrateController* CongestionController::GetBitrateController() const {
   return bitrate_controller_.get();
 }