Add OnTrack PeerConnection callback for Unified Plan
This adds a callback corresponding to the ontrack event as defined
in the WebRTC specification.
Bug: webrtc:7600
Change-Id: Ied8c55e11dcea864428fb194623c1595c21657c7
Reviewed-on: https://webrtc-review.googlesource.com/52660
Commit-Queue: Steve Anton <steveanton@webrtc.org>
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22066}diff --git a/api/peerconnectioninterface.h b/api/peerconnectioninterface.h
index 5786859..5784d95 100644
--- a/api/peerconnectioninterface.h
+++ b/api/peerconnectioninterface.h
@@ -1050,10 +1050,25 @@
// This is called when a receiver and its track is created.
// TODO(zhihuang): Make this pure virtual when all subclasses implement it.
+ // Note: This is called with both Plan B and Unified Plan semantics. Unified
+ // Plan users should prefer OnTrack, OnAddTrack is only called as backwards
+ // compatibility (and is called in the exact same situations as OnTrack).
virtual void OnAddTrack(
rtc::scoped_refptr<RtpReceiverInterface> receiver,
const std::vector<rtc::scoped_refptr<MediaStreamInterface>>& streams) {}
+ // This is called when signaling indicates a transceiver will be receiving
+ // media from the remote endpoint. This is fired during a call to
+ // SetRemoteDescription. The receiving track can be accessed by:
+ // |transceiver->receiver()->track()| and its associated streams by
+ // |transceiver->receiver()->streams()|.
+ // Note: This will only be called if Unified Plan semantics are specified.
+ // This behavior is specified in section 2.2.8.2.5 of the "Set the
+ // RTCSessionDescription" algorithm:
+ // https://w3c.github.io/webrtc-pc/#set-description
+ virtual void OnTrack(
+ rtc::scoped_refptr<RtpTransceiverInterface> transceiver) {}
+
// TODO(hbos,deadbeef): Add |OnAssociatedStreamsUpdated| with |receiver| and
// |streams| as arguments. This should be called when an existing receiver its
// associated streams updated. https://crbug.com/webrtc/8315
@@ -1065,7 +1080,7 @@
// behavior that occurs when processing the removal of a remote track, and is
// called when the receiver is removed and the track is muted. When Unified
// Plan SDP is supported, transceivers can change direction (and receivers
- // stopped) but receivers are never removed.
+ // stopped) but receivers are never removed, so this is never called.
// https://w3c.github.io/webrtc-pc/#process-remote-track-removal
// TODO(hbos,deadbeef): When Unified Plan SDP is supported and receivers are
// no longer removed, deprecate and remove this callback.
diff --git a/pc/peerconnection.cc b/pc/peerconnection.cc
index 3982267..f04b6e5 100644
--- a/pc/peerconnection.cc
+++ b/pc/peerconnection.cc
@@ -2155,7 +2155,8 @@
}
if (IsUnifiedPlan()) {
- std::vector<TrackEvent> track_events;
+ std::vector<rtc::scoped_refptr<RtpTransceiverInterface>>
+ receiving_transceivers;
std::vector<rtc::scoped_refptr<MediaStreamInterface>> added_streams;
for (auto transceiver : transceivers_) {
const ContentInfo* content =
@@ -2185,10 +2186,7 @@
added_streams.push_back(stream);
}
transceiver->internal()->receiver_internal()->SetStreams({stream});
- TrackEvent track_event;
- track_event.receiver = transceiver->receiver();
- track_event.streams = transceiver->receiver()->streams();
- track_events.push_back(std::move(track_event));
+ receiving_transceivers.push_back(transceiver);
}
// If direction is sendonly or inactive, and transceiver's current
// direction is neither sendonly nor inactive, process the removal of a
@@ -2210,8 +2208,10 @@
}
}
// Once all processing has finished, fire off callbacks.
- for (auto event : track_events) {
- observer_->OnAddTrack(event.receiver, event.streams);
+ for (auto transceiver : receiving_transceivers) {
+ observer_->OnTrack(transceiver);
+ observer_->OnAddTrack(transceiver->receiver(),
+ transceiver->receiver()->streams());
}
for (auto stream : added_streams) {
observer_->OnAddStream(stream);
diff --git a/pc/peerconnection.h b/pc/peerconnection.h
index e6d7b7e..3eccb96 100644
--- a/pc/peerconnection.h
+++ b/pc/peerconnection.h
@@ -292,11 +292,6 @@
uint32_t first_ssrc;
};
- struct TrackEvent {
- rtc::scoped_refptr<RtpReceiverInterface> receiver;
- std::vector<rtc::scoped_refptr<MediaStreamInterface>> streams;
- };
-
// Implements MessageHandler.
void OnMessage(rtc::Message* msg) override;
diff --git a/pc/peerconnection_rtp_unittest.cc b/pc/peerconnection_rtp_unittest.cc
index 2f20261..09d2dbe 100644
--- a/pc/peerconnection_rtp_unittest.cc
+++ b/pc/peerconnection_rtp_unittest.cc
@@ -219,6 +219,106 @@
callee->observer()->remove_track_events_);
}
+// Tests that setting a remote description with sending transceivers will fire
+// the OnTrack callback for each transceiver and setting a remote description
+// with receive only transceivers will not call OnTrack.
+TEST_F(PeerConnectionRtpCallbacksTest, UnifiedPlanAddTransceiverCallsOnTrack) {
+ auto caller = CreatePeerConnectionWithUnifiedPlan();
+ auto callee = CreatePeerConnectionWithUnifiedPlan();
+
+ auto audio_transceiver = caller->AddTransceiver(cricket::MEDIA_TYPE_AUDIO);
+ auto video_transceiver = caller->AddTransceiver(cricket::MEDIA_TYPE_VIDEO);
+
+ ASSERT_TRUE(caller->ExchangeOfferAnswerWith(callee.get()));
+
+ ASSERT_EQ(0u, caller->observer()->on_track_transceivers_.size());
+ ASSERT_EQ(2u, callee->observer()->on_track_transceivers_.size());
+ EXPECT_EQ(audio_transceiver->mid(),
+ callee->pc()->GetTransceivers()[0]->mid());
+ EXPECT_EQ(video_transceiver->mid(),
+ callee->pc()->GetTransceivers()[1]->mid());
+}
+
+// Test that doing additional offer/answer exchanges with no changes to tracks
+// will cause no additional OnTrack calls after the tracks have been negotiated.
+TEST_F(PeerConnectionRtpCallbacksTest, UnifiedPlanReofferDoesNotCallOnTrack) {
+ auto caller = CreatePeerConnectionWithUnifiedPlan();
+ auto callee = CreatePeerConnectionWithUnifiedPlan();
+
+ caller->AddAudioTrack("audio");
+ callee->AddAudioTrack("audio");
+
+ ASSERT_TRUE(caller->ExchangeOfferAnswerWith(callee.get()));
+ EXPECT_EQ(1u, caller->observer()->on_track_transceivers_.size());
+ EXPECT_EQ(1u, callee->observer()->on_track_transceivers_.size());
+
+ // If caller reoffers with no changes expect no additional OnTrack calls.
+ ASSERT_TRUE(caller->ExchangeOfferAnswerWith(callee.get()));
+ EXPECT_EQ(1u, caller->observer()->on_track_transceivers_.size());
+ EXPECT_EQ(1u, callee->observer()->on_track_transceivers_.size());
+
+ // Also if callee reoffers with no changes expect no additional OnTrack calls.
+ ASSERT_TRUE(callee->ExchangeOfferAnswerWith(caller.get()));
+ EXPECT_EQ(1u, caller->observer()->on_track_transceivers_.size());
+ EXPECT_EQ(1u, callee->observer()->on_track_transceivers_.size());
+}
+
+// Test that OnTrack is called when the transceiver direction changes to send
+// the track.
+TEST_F(PeerConnectionRtpCallbacksTest, UnifiedPlanSetDirectionCallsOnTrack) {
+ auto caller = CreatePeerConnectionWithUnifiedPlan();
+ auto callee = CreatePeerConnectionWithUnifiedPlan();
+
+ auto transceiver = caller->AddTransceiver(cricket::MEDIA_TYPE_AUDIO);
+ transceiver->SetDirection(RtpTransceiverDirection::kInactive);
+ ASSERT_TRUE(caller->ExchangeOfferAnswerWith(callee.get()));
+ EXPECT_EQ(0u, caller->observer()->on_track_transceivers_.size());
+ EXPECT_EQ(0u, callee->observer()->on_track_transceivers_.size());
+
+ transceiver->SetDirection(RtpTransceiverDirection::kSendOnly);
+ ASSERT_TRUE(caller->ExchangeOfferAnswerWith(callee.get()));
+ EXPECT_EQ(0u, caller->observer()->on_track_transceivers_.size());
+ EXPECT_EQ(1u, callee->observer()->on_track_transceivers_.size());
+
+ // If the direction changes but it is still receiving on the remote side, then
+ // OnTrack should not be fired again.
+ transceiver->SetDirection(RtpTransceiverDirection::kSendRecv);
+ ASSERT_TRUE(caller->ExchangeOfferAnswerWith(callee.get()));
+ EXPECT_EQ(0u, caller->observer()->on_track_transceivers_.size());
+ EXPECT_EQ(1u, callee->observer()->on_track_transceivers_.size());
+}
+
+// Test that OnTrack is called twice when a sendrecv call is started, the callee
+// changes the direction to inactive, then changes it back to sendrecv.
+TEST_F(PeerConnectionRtpCallbacksTest,
+ UnifiedPlanSetDirectionHoldCallsOnTrackTwice) {
+ auto caller = CreatePeerConnectionWithUnifiedPlan();
+ auto callee = CreatePeerConnectionWithUnifiedPlan();
+
+ auto transceiver = caller->AddTransceiver(cricket::MEDIA_TYPE_AUDIO);
+
+ ASSERT_TRUE(caller->ExchangeOfferAnswerWith(callee.get()));
+ EXPECT_EQ(0u, caller->observer()->on_track_transceivers_.size());
+ EXPECT_EQ(1u, callee->observer()->on_track_transceivers_.size());
+
+ // Put the call on hold by no longer receiving the track.
+ callee->pc()->GetTransceivers()[0]->SetDirection(
+ RtpTransceiverDirection::kInactive);
+
+ ASSERT_TRUE(callee->ExchangeOfferAnswerWith(caller.get()));
+ EXPECT_EQ(0u, caller->observer()->on_track_transceivers_.size());
+ EXPECT_EQ(1u, callee->observer()->on_track_transceivers_.size());
+
+ // Resume the call by changing the direction to recvonly. This should call
+ // OnTrack again on the callee side.
+ callee->pc()->GetTransceivers()[0]->SetDirection(
+ RtpTransceiverDirection::kRecvOnly);
+
+ ASSERT_TRUE(callee->ExchangeOfferAnswerWith(caller.get()));
+ EXPECT_EQ(0u, caller->observer()->on_track_transceivers_.size());
+ EXPECT_EQ(2u, callee->observer()->on_track_transceivers_.size());
+}
+
// These tests examine the state of the peer connection as a result of
// performing SetRemoteDescription().
class PeerConnectionRtpObserverTest : public PeerConnectionRtpTest {};
diff --git a/pc/test/mockpeerconnectionobservers.h b/pc/test/mockpeerconnectionobservers.h
index a7e4884..10979fd 100644
--- a/pc/test/mockpeerconnectionobservers.h
+++ b/pc/test/mockpeerconnectionobservers.h
@@ -132,6 +132,11 @@
add_track_events_.push_back(AddTrackEvent(receiver, streams));
}
+ void OnTrack(
+ rtc::scoped_refptr<RtpTransceiverInterface> transceiver) override {
+ on_track_transceivers_.push_back(transceiver);
+ }
+
void OnRemoveTrack(
rtc::scoped_refptr<RtpReceiverInterface> receiver) override {
remove_track_events_.push_back(receiver);
@@ -209,6 +214,8 @@
std::string last_added_track_label_;
std::vector<AddTrackEvent> add_track_events_;
std::vector<rtc::scoped_refptr<RtpReceiverInterface>> remove_track_events_;
+ std::vector<rtc::scoped_refptr<RtpTransceiverInterface>>
+ on_track_transceivers_;
int num_candidates_removed_ = 0;
private:
