diff --git a/talk/app/webrtc/mediaconstraintsinterface.cc b/talk/app/webrtc/mediaconstraintsinterface.cc
index c38369581..0ecadd691 100644
--- a/talk/app/webrtc/mediaconstraintsinterface.cc
+++ b/talk/app/webrtc/mediaconstraintsinterface.cc
@@ -97,6 +97,8 @@ const char MediaConstraintsInterface::kImprovedWifiBwe[] =
     "googImprovedWifiBwe";
 const char MediaConstraintsInterface::kScreencastMinBitrate[] =
     "googScreencastMinBitrate";
+const char MediaConstraintsInterface::kSkipEncodingUnusedStreams[] =
+    "googSkipEncodingUnusedStreams";
 // TODO(ronghuawu): Remove once cpu overuse detection is stable.
 const char MediaConstraintsInterface::kCpuOveruseDetection[] =
     "googCpuOveruseDetection";
diff --git a/talk/app/webrtc/mediaconstraintsinterface.h b/talk/app/webrtc/mediaconstraintsinterface.h
index 1304d88d4..2ac251623 100644
--- a/talk/app/webrtc/mediaconstraintsinterface.h
+++ b/talk/app/webrtc/mediaconstraintsinterface.h
@@ -117,6 +117,8 @@ class MediaConstraintsInterface {
       // googSuspendBelowMinBitrate
   static const char kImprovedWifiBwe[];  // googImprovedWifiBwe
   static const char kScreencastMinBitrate[];  // googScreencastMinBitrate
+  static const char kSkipEncodingUnusedStreams[];
+      // googSkipEncodingUnusedStreams
   static const char kCpuOveruseDetection[];  // googCpuOveruseDetection
   static const char kCpuUnderuseThreshold[];  // googCpuUnderuseThreshold
   static const char kCpuOveruseThreshold[];  // googCpuOveruseThreshold
diff --git a/talk/app/webrtc/webrtcsession.cc b/talk/app/webrtc/webrtcsession.cc
index 6f745fc42..ddc887629 100644
--- a/talk/app/webrtc/webrtcsession.cc
+++ b/talk/app/webrtc/webrtcsession.cc
@@ -548,6 +548,14 @@ bool WebRtcSession::Initialize(
     video_options_.suspend_below_min_bitrate.Set(value);
   }
 
+  if (FindConstraint(
+      constraints,
+      MediaConstraintsInterface::kSkipEncodingUnusedStreams,
+      &value,
+      NULL)) {
+    video_options_.skip_encoding_unused_streams.Set(value);
+  }
+
   SetOptionFromOptionalConstraint(constraints,
       MediaConstraintsInterface::kScreencastMinBitrate,
       &video_options_.screencast_min_bitrate);
diff --git a/talk/media/base/mediachannel.h b/talk/media/base/mediachannel.h
index ac62d5e2d..60cdebda3 100644
--- a/talk/media/base/mediachannel.h
+++ b/talk/media/base/mediachannel.h
@@ -312,6 +312,8 @@ struct VideoOptions {
     video_start_bitrate.SetFrom(change.video_start_bitrate);
     video_temporal_layer_screencast.SetFrom(
         change.video_temporal_layer_screencast);
+    video_temporal_layer_realtime.SetFrom(
+        change.video_temporal_layer_realtime);
     video_leaky_bucket.SetFrom(change.video_leaky_bucket);
     video_highest_bitrate.SetFrom(change.video_highest_bitrate);
     cpu_overuse_detection.SetFrom(change.cpu_overuse_detection);
@@ -334,6 +336,7 @@ struct VideoOptions {
     suspend_below_min_bitrate.SetFrom(change.suspend_below_min_bitrate);
     unsignalled_recv_stream_limit.SetFrom(change.unsignalled_recv_stream_limit);
     use_simulcast_adapter.SetFrom(change.use_simulcast_adapter);
+    skip_encoding_unused_streams.SetFrom(change.skip_encoding_unused_streams);
     screencast_min_bitrate.SetFrom(change.screencast_min_bitrate);
     use_improved_wifi_bandwidth_estimator.SetFrom(
         change.use_improved_wifi_bandwidth_estimator);
@@ -351,6 +354,7 @@ struct VideoOptions {
         video_high_bitrate == o.video_high_bitrate &&
         video_start_bitrate == o.video_start_bitrate &&
         video_temporal_layer_screencast == o.video_temporal_layer_screencast &&
+        video_temporal_layer_realtime == o.video_temporal_layer_realtime &&
         video_leaky_bucket == o.video_leaky_bucket &&
         video_highest_bitrate == o.video_highest_bitrate &&
         cpu_overuse_detection == o.cpu_overuse_detection &&
@@ -373,6 +377,7 @@ struct VideoOptions {
         suspend_below_min_bitrate == o.suspend_below_min_bitrate &&
         unsignalled_recv_stream_limit == o.unsignalled_recv_stream_limit &&
         use_simulcast_adapter == o.use_simulcast_adapter &&
+        skip_encoding_unused_streams == o.skip_encoding_unused_streams &&
         screencast_min_bitrate == o.screencast_min_bitrate &&
         use_improved_wifi_bandwidth_estimator ==
             o.use_improved_wifi_bandwidth_estimator &&
@@ -393,6 +398,8 @@ struct VideoOptions {
     ost << ToStringIfSet("start bitrate", video_start_bitrate);
     ost << ToStringIfSet("video temporal layer screencast",
                          video_temporal_layer_screencast);
+    ost << ToStringIfSet("video temporal layer realtime",
+                         video_temporal_layer_realtime);
     ost << ToStringIfSet("leaky bucket", video_leaky_bucket);
     ost << ToStringIfSet("highest video bitrate", video_highest_bitrate);
     ost << ToStringIfSet("cpu overuse detection", cpu_overuse_detection);
@@ -416,6 +423,8 @@ struct VideoOptions {
     ost << ToStringIfSet("num channels for early receive",
                          unsignalled_recv_stream_limit);
     ost << ToStringIfSet("use simulcast adapter", use_simulcast_adapter);
+    ost << ToStringIfSet("skip encoding unused streams",
+                         skip_encoding_unused_streams);
     ost << ToStringIfSet("screencast min bitrate", screencast_min_bitrate);
     ost << ToStringIfSet("improved wifi bwe",
                          use_improved_wifi_bandwidth_estimator);
@@ -444,6 +453,8 @@ struct VideoOptions {
   Settable<int> video_start_bitrate;
   // Experimental: Enable WebRTC layered screencast.
   Settable<bool> video_temporal_layer_screencast;
+  // Experimental: Enable WebRTC temporal layer strategy for realtime video.
+  Settable<bool> video_temporal_layer_realtime;
   // Enable WebRTC leaky bucket when sending media packets.
   Settable<bool> video_leaky_bucket;
   // Set highest bitrate mode for video.
@@ -491,6 +502,9 @@ struct VideoOptions {
   Settable<int> unsignalled_recv_stream_limit;
   // Enable use of simulcast adapter.
   Settable<bool> use_simulcast_adapter;
+  // Enables the encoder to skip encoding stream not actually sent due to too
+  // low available bit rate.
+  Settable<bool> skip_encoding_unused_streams;
   // Force screencast to use a minimum bitrate
   Settable<int> screencast_min_bitrate;
   // Enable improved bandwidth estiamtor on wifi.