--- a/media/webrtc/signaling/src/media-conduit/VideoConduit.cpp
+++ b/media/webrtc/signaling/src/media-conduit/VideoConduit.cpp
@@ -709,16 +709,17 @@ WebrtcVideoConduit::ConfigureSendMediaCo
 
   if(codecFound == false)
   {
     CSFLogError(logTag, "%s Codec Mismatch ", __FUNCTION__);
     return kMediaConduitInvalidSendCodec;
   }
   // Note: only for overriding parameters from GetCodec()!
   CodecConfigToWebRTCCodec(codecConfig, video_codec);
+  video_codec.mode = mCodecMode;
 
   if(mPtrViECodec->SetSendCodec(mChannel, video_codec) == -1)
   {
     error = mPtrViEBase->LastError();
     if(error == kViECodecInvalidCodec)
     {
       CSFLogError(logTag, "%s Invalid Send Codec", __FUNCTION__);
       return kMediaConduitInvalidSendCodec;
@@ -1407,16 +1408,17 @@ WebrtcVideoConduit::ReconfigureSendCodec
   }
   if (vie_codec.numberOfSimulcastStreams != 0) {
     vie_codec.minBitrate = std::max(minMinBitrate, vie_codec.minBitrate);
     vie_codec.maxBitrate = std::min(totalMaxBitrate, vie_codec.maxBitrate);
     vie_codec.startBitrate = std::max(vie_codec.minBitrate,
                                       std::min(minStartBitrate,
                                                vie_codec.maxBitrate));
   }
+  vie_codec.mode = mCodecMode;
   if ((err = mPtrViECodec->SetSendCodec(mChannel, vie_codec)) != 0)
   {
     CSFLogError(logTag, "%s: SetSendCodec(%ux%u) failed, err %d",
                 __FUNCTION__, width, height, err);
     return NS_ERROR_FAILURE;
   }
   if (mMinBitrateEstimate != 0) {
     mPtrViENetwork->SetBitrateConfig(mChannel,

--- a/media/webrtc/signaling/src/peerconnection/PeerConnectionImpl.cpp
+++ b/media/webrtc/signaling/src/peerconnection/PeerConnectionImpl.cpp
@@ -2511,16 +2511,21 @@ PeerConnectionImpl::ReplaceTrack(MediaSt
     return NS_OK;
   }
   aThisTrack.RemovePrincipalChangeObserver(this);
   aWithTrack.AddPrincipalChangeObserver(this);
 #if !defined(MOZILLA_EXTERNAL_LINKAGE)
   PrincipalChanged(&aWithTrack);
 #endif
 
+  // We update the media pipelines here so we can apply different codec
+  // settings for different sources (e.g. screensharing as opposed to camera.)
+  // TODO: We should probably only do this if the source has in fact changed.
+  mMedia->UpdateMediaPipelines(*mJsepSession);
+
   pco->OnReplaceTrackSuccess(jrv);
   if (jrv.Failed()) {
     CSFLogError(logTag, "Error firing replaceTrack success callback");
     return NS_ERROR_UNEXPECTED;
   }
 
   return NS_OK;
 }

--- a/media/webrtc/trunk/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
+++ b/media/webrtc/trunk/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
@@ -680,17 +680,18 @@ int VP8EncoderImpl::InitAndSetControlSet
                     codec_.codecSpecific.VP8.denoisingOn ?
                     denoiser_state : kDenoiserOff);
   if (encoders_.size() > 2) {
     vpx_codec_control(&encoders_[1], VP8E_SET_NOISE_SENSITIVITY,
                       codec_.codecSpecific.VP8.denoisingOn ?
                       denoiser_state : kDenoiserOff);
   }
   for (size_t i = 0; i < encoders_.size(); ++i) {
-    vpx_codec_control(&(encoders_[i]), VP8E_SET_STATIC_THRESHOLD, 1);
+    vpx_codec_control(&(encoders_[i]), VP8E_SET_STATIC_THRESHOLD,
+                      codec_.mode == kScreensharing ? 300 : 1);
     vpx_codec_control(&(encoders_[i]), VP8E_SET_CPUUSED, cpu_speed_[i]);
     vpx_codec_control(&(encoders_[i]), VP8E_SET_TOKEN_PARTITIONS,
                       static_cast<vp8e_token_partitions>(token_partitions_));
     vpx_codec_control(&(encoders_[i]), VP8E_SET_MAX_INTRA_BITRATE_PCT,
                       rc_max_intra_target_);
     vpx_codec_control(&(encoders_[i]), VP8E_SET_SCREEN_CONTENT_MODE,
                       codec_.mode == kScreensharing);
   }