3 files changed, 16 insertions, 10 deletions
diff --git a/dom/media/webrtc/jsep/JsepSessionImpl.cpp b/dom/media/webrtc/jsep/JsepSessionImpl.cpp
index 50def6eb6c..c091b6d618 100644
--- a/dom/media/webrtc/jsep/JsepSessionImpl.cpp
+++ b/dom/media/webrtc/jsep/JsepSessionImpl.cpp
@@ -1121,11 +1121,17 @@ nsresult JsepSessionImpl::HandleNegotiatedSession(
 
   CopyBundleTransports();
 
-  std::vector<JsepTrack*> remoteTracks;
+  std::vector<JsepTrack*> receiveTracks;
   for (auto& transceiver : mTransceivers) {
-    remoteTracks.push_back(&transceiver.mRecvTrack);
+    // Do not count payload types for non-active recv tracks as duplicates. If
+    // we receive an RTP packet with a payload type that is used by both a
+    // sendrecv and a sendonly m-section, there is no ambiguity; it is for the
+    // sendrecv m-section.
+    if (transceiver.mRecvTrack.GetActive()) {
+      receiveTracks.push_back(&transceiver.mRecvTrack);
+    }
   }
-  JsepTrack::SetUniquePayloadTypes(remoteTracks);
+  JsepTrack::SetUniqueReceivePayloadTypes(receiveTracks);
 
   mNegotiations++;
 
diff --git a/dom/media/webrtc/jsep/JsepTrack.cpp b/dom/media/webrtc/jsep/JsepTrack.cpp
index 59c038cfc0..2498200ab2 100644
--- a/dom/media/webrtc/jsep/JsepTrack.cpp
+++ b/dom/media/webrtc/jsep/JsepTrack.cpp
@@ -662,7 +662,7 @@ nsresult JsepTrack::Negotiate(const SdpMediaSection& answer,
 // works, however, if that payload type appeared in only one m-section.
 // We figure that out here.
 /* static */
-void JsepTrack::SetUniquePayloadTypes(std::vector<JsepTrack*>& tracks) {
+void JsepTrack::SetUniqueReceivePayloadTypes(std::vector<JsepTrack*>& tracks) {
   // Maps to track details if no other track contains the payload type,
   // otherwise maps to nullptr.
   std::map<uint16_t, JsepTrackNegotiatedDetails*> payloadTypeToDetailsMap;
@@ -697,7 +697,7 @@ void JsepTrack::SetUniquePayloadTypes(std::vector<JsepTrack*>& tracks) {
     auto trackDetails = ptAndDetails.second;
 
     if (trackDetails) {
-      trackDetails->mUniquePayloadTypes.push_back(
+      trackDetails->mUniqueReceivePayloadTypes.push_back(
           static_cast<uint8_t>(uniquePt));
     }
   }
diff --git a/dom/media/webrtc/jsep/JsepTrack.h b/dom/media/webrtc/jsep/JsepTrack.h
index d11735f43a..74a0d2396c 100644
--- a/dom/media/webrtc/jsep/JsepTrack.h
+++ b/dom/media/webrtc/jsep/JsepTrack.h
@@ -31,7 +31,7 @@ class JsepTrackNegotiatedDetails {
 
   JsepTrackNegotiatedDetails(const JsepTrackNegotiatedDetails& orig)
       : mExtmap(orig.mExtmap),
-        mUniquePayloadTypes(orig.mUniquePayloadTypes),
+        mUniqueReceivePayloadTypes(orig.mUniqueReceivePayloadTypes),
         mTias(orig.mTias),
         mRtpRtcpConf(orig.mRtpRtcpConf) {
     for (const auto& encoding : orig.mEncodings) {
@@ -71,8 +71,8 @@ class JsepTrackNegotiatedDetails {
     }
   }
 
-  std::vector<uint8_t> GetUniquePayloadTypes() const {
-    return mUniquePayloadTypes;
+  std::vector<uint8_t> GetUniqueReceivePayloadTypes() const {
+    return mUniqueReceivePayloadTypes;
   }
 
   uint32_t GetTias() const { return mTias; }
@@ -83,7 +83,7 @@ class JsepTrackNegotiatedDetails {
   friend class JsepTrack;
 
   std::map<std::string, SdpExtmapAttributeList::Extmap> mExtmap;
-  std::vector<uint8_t> mUniquePayloadTypes;
+  std::vector<uint8_t> mUniqueReceivePayloadTypes;
   std::vector<UniquePtr<JsepTrackEncoding>> mEncodings;
   uint32_t mTias;  // bits per second
   RtpRtcpConfig mRtpRtcpConf;
@@ -214,7 +214,7 @@ class JsepTrack {
   virtual nsresult Negotiate(const SdpMediaSection& answer,
                              const SdpMediaSection& remote,
                              const SdpMediaSection& local);
-  static void SetUniquePayloadTypes(std::vector<JsepTrack*>& tracks);
+  static void SetUniqueReceivePayloadTypes(std::vector<JsepTrack*>& tracks);
   virtual void GetNegotiatedPayloadTypes(
       std::vector<uint16_t>* payloadTypes) const;