commit fc1acd23644af0a8d3cfadb1888f8c15c68b5642
author Jonas Oreland <jonaso@webrtc.org> Fri Aug 24 10:58:37 2018 +0200
committer Commit Bot <commit-bot@chromium.org> Fri Aug 24 09:55:59 2018 +0000
tree 6cf70a6a5c05d74be1e1019e86a3db033b8300dd
parent d65e143801a7aaa9affdb939ea836aec1955cdcc

Add support for enabling simulcast in "Plan B" using MediaConstraints.

BUG=webrtc:9655

Change-Id: Ieb5fe5d97b6d4381608a51593bca5423979d1b9f
Reviewed-on: https://webrtc-review.googlesource.com/95481
Commit-Queue: Jonas Oreland <jonaso@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Seth Hampson <shampson@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24424}

api/mediaconstraintsinterface.cc

diff --git a/api/mediaconstraintsinterface.cc b/api/mediaconstraintsinterface.cc
index c892606..80c447d 100644
--- a/api/mediaconstraintsinterface.cc
+++ b/api/mediaconstraintsinterface.cc
@@ -146,6 +146,9 @@
     "googCpuOveruseDetection";
 const char MediaConstraintsInterface::kPayloadPadding[] = "googPayloadPadding";
 
+const char MediaConstraintsInterface::kNumSimulcastLayers[] =
+    "googNumSimulcastLayers";
+
 // Set |value| to the value associated with the first appearance of |key|, or
 // return false if |key| is not found.
 bool MediaConstraintsInterface::Constraints::FindFirst(
@@ -301,6 +304,13 @@
     offer_answer_options->ice_restart = value;
   }
 
+  int layers;
+  if (FindConstraint(constraints,
+                     MediaConstraintsInterface::kNumSimulcastLayers,
+                     &layers, &mandatory_constraints_satisfied)) {
+    offer_answer_options->num_simulcast_layers = layers;
+  }
+
   return mandatory_constraints_satisfied == constraints->GetMandatory().size();
 }
 

api/mediaconstraintsinterface.h

diff --git a/api/mediaconstraintsinterface.h b/api/mediaconstraintsinterface.h
index 3c85dfb..6128e6a 100644
--- a/api/mediaconstraintsinterface.h
+++ b/api/mediaconstraintsinterface.h
@@ -119,6 +119,11 @@
   // stripped by Chrome before passed down to Libjingle.
   static const char kInternalConstraintPrefix[];
 
+  // Specifies number of simulcast layers for all video tracks
+  // with a Plan B offer/answer
+  // (see RTCOfferAnswerOptions::num_simulcast_layers).
+  static const char kNumSimulcastLayers[];
+
   virtual ~MediaConstraintsInterface() = default;
 
   virtual const Constraints& GetMandatory() const = 0;

api/peerconnectioninterface.h

diff --git a/api/peerconnectioninterface.h b/api/peerconnectioninterface.h
index 84a0501..2b94ee8 100644
--- a/api/peerconnectioninterface.h
+++ b/api/peerconnectioninterface.h
@@ -596,6 +596,9 @@
     // confused with RTCP mux (multiplexing RTP and RTCP together).
     bool use_rtp_mux = true;
 
+    // This will apply to all video tracks with a Plan B SDP offer/answer.
+    int num_simulcast_layers = 1;
+
     RTCOfferAnswerOptions() = default;
 
     RTCOfferAnswerOptions(int offer_to_receive_video,