Only update REMB value if there is a calid bitrate estimate.

BUG=
TEST=

Review URL: http://webrtc-codereview.appspot.com/352005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@1421 4adac7df-926f-26a2-2b94-8c16560cd09d

src/modules/rtp_rtcp/source/remote_rate_control.cc

@@ -79,6 +79,10 @@ void RemoteRateControl::Reset()
     _initializedBitRate = false;
 }
 
+bool RemoteRateControl::ValidEstimate() {
+  return _initializedBitRate;
+}
+
 WebRtc_Word32 RemoteRateControl::SetConfiguredBitRates(WebRtc_UWord32 minBitRateBps, WebRtc_UWord32 maxBitRateBps)
 {
     if (minBitRateBps > maxBitRateBps)

src/modules/rtp_rtcp/source/remote_rate_control.h

@@ -31,6 +31,10 @@ public:
                              WebRtc_Word64 nowMS);
     void Reset();
 
+    // Returns true if there is a valid estimate of the incoming bitrate, false
+    // otherwise.
+    bool ValidEstimate();
+
 private:
     WebRtc_UWord32 ChangeBitRate(WebRtc_UWord32 currentBitRate,
                                  WebRtc_UWord32 incomingBitRate,

src/modules/rtp_rtcp/source/rtcp_sender.cc

@@ -282,7 +282,7 @@ bool RTCPSender::SetRemoteBitrateObserver(RtpRemoteBitrateObserver* observer) {
 
 void RTCPSender::UpdateRemoteBitrateEstimate(unsigned int target_bitrate) {
   CriticalSectionScoped lock(_criticalSectionRTCPSender);
-  if (_bitrate_observer && _remoteSSRC != 0) {
+  if (_bitrate_observer) {
     _bitrate_observer->OnReceiveBitrateChanged(_remoteSSRC, target_bitrate);
   }
 }
@@ -1191,12 +1191,19 @@ RTCPSender::BuildREMB(WebRtc_UWord8* rtcpbuffer, WebRtc_UWord32& pos)
 WebRtc_UWord32
 RTCPSender::CalculateNewTargetBitrate(WebRtc_UWord32 RTT)
 {
+    CriticalSectionScoped lock(_criticalSectionRTCPSender);
     WebRtc_UWord32 target_bitrate =
         _remoteRateControl.TargetBitRate(RTT, _clock.GetTimeInMS());
     _tmmbr_Send = target_bitrate / 1000;
     return target_bitrate;
 }
 
+bool
+RTCPSender::ValidBitrateEstimate() {
+  CriticalSectionScoped lock(_criticalSectionRTCPSender);
+  return _remoteRateControl.ValidEstimate();
+}
+
 WebRtc_Word32
 RTCPSender::BuildTMMBR(WebRtc_UWord8* rtcpbuffer, WebRtc_UWord32& pos)
 {

src/modules/rtp_rtcp/source/rtcp_sender.h

@@ -133,6 +133,10 @@ public:
 
     WebRtc_UWord32 CalculateNewTargetBitrate(WebRtc_UWord32 RTT);
 
+    // Returns true if there is a valid estimate of the incoming bitrate, false
+    // otherwise.
+    bool ValidBitrateEstimate();
+
 private:
     WebRtc_Word32 SendToNetwork(const WebRtc_UWord8* dataBuffer,
                               const WebRtc_UWord16 length);

src/modules/rtp_rtcp/source/rtp_rtcp_impl.cc

@@ -415,7 +415,7 @@ WebRtc_Word32 ModuleRtpRtcpImpl::Process()
     {
         WebRtc_UWord16 RTT = 0;
         _rtcpReceiver.RTT(_rtpReceiver.SSRC(), &RTT, NULL, NULL, NULL);
-        if (REMB())
+        if (REMB() && _rtcpSender.ValidBitrateEstimate())
         {
           unsigned int target_bitrate =
               _rtcpSender.CalculateNewTargetBitrate(RTT);