Generate track stats when SSRC=0

This will generate an all-zeroes track stat when the sender
has not yet been connected (SSRC has not been assigned).

Bug: webrtc:8673
Change-Id: Id59e6941bc87eba6bb33b4d2a8fd808d985052c7
Reviewed-on: https://webrtc-review.googlesource.com/43080
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21734}

media/base/mediachannel.h

@@ -311,11 +311,15 @@ struct MediaSenderInfo {
     }
     return retval;
   }
+  // Returns true if the media has been connected.
+  bool connected() const { return local_stats.size() > 0; }
   // Utility accessor for clients that make the assumption only one ssrc
   // exists per media.
   // This will eventually go away.
+  // Call sites that compare this to zero should use connected() instead.
+  // https://bugs.webrtc.org/8694
   uint32_t ssrc() const {
-    if (local_stats.size() > 0) {
+    if (connected()) {
       return local_stats[0].ssrc;
     } else {
       return 0;
@@ -351,11 +355,15 @@ struct MediaReceiverInfo {
     }
     return retval;
   }
+  // Returns true if the media has been connected.
+  bool connected() const { return local_stats.size() > 0; }
   // Utility accessor for clients that make the assumption only one ssrc
   // exists per media.
   // This will eventually go away.
+  // Call sites that compare this to zero should use connected();
+  // https://bugs.webrtc.org/8694
   uint32_t ssrc() const {
-    if (local_stats.size() > 0) {
+    if (connected()) {
       return local_stats[0].ssrc;
     } else {
       return 0;

pc/rtcstatscollector.cc

@@ -510,17 +510,21 @@ void ProduceSenderMediaTrackStats(
   // gathering at the time of detachment to get accurate stats and timestamps.
   // https://crbug.com/659137
   for (auto const sender : senders) {
-    // Don't report on tracks before starting to send.
-    // https://bugs.webrtc.org/8673
-    if (sender->ssrc() == 0)
-      continue;
     if (sender->media_type() == cricket::MEDIA_TYPE_AUDIO) {
       AudioTrackInterface* track =
           static_cast<AudioTrackInterface*>(sender->track().get());
       if (!track)
         continue;
-      auto voice_sender_info =
+      cricket::VoiceSenderInfo null_sender_info;
-          track_media_info_map.GetVoiceSenderInfoBySsrc(sender->ssrc());
+      const cricket::VoiceSenderInfo* voice_sender_info = &null_sender_info;
+      // TODO(hta): Checking on ssrc is not proper. There should be a way
+      // to see from a sender whether it's connected or not.
+      // Related to https://crbug.com/8694 (using ssrc 0 to indicate "none")
+      if (sender->ssrc()) {
+        voice_sender_info =
+            track_media_info_map.GetVoiceSenderInfoBySsrc(sender->ssrc());
+      }
+
       RTC_CHECK(voice_sender_info)
           << "No voice sender info for sender with ssrc " << sender->ssrc();
       std::unique_ptr<RTCMediaStreamTrackStats> audio_track_stats =
@@ -532,8 +536,13 @@ void ProduceSenderMediaTrackStats(
           static_cast<VideoTrackInterface*>(sender->track().get());
       if (!track)
         continue;
-      auto video_sender_info =
+      cricket::VideoSenderInfo null_sender_info;
-          track_media_info_map.GetVideoSenderInfoBySsrc(sender->ssrc());
+      const cricket::VideoSenderInfo* video_sender_info = &null_sender_info;
+      // TODO(hta): Check on state not ssrc when state is available
+      // Related to https://crbug.com/8694 (using ssrc 0 to indicate "none")
+      if (sender->ssrc())
+        video_sender_info =
+            track_media_info_map.GetVideoSenderInfoBySsrc(sender->ssrc());
       RTC_CHECK(video_sender_info)
           << "No video sender info for sender with ssrc " << sender->ssrc();
       std::unique_ptr<RTCMediaStreamTrackStats> video_track_stats =
@@ -1019,16 +1028,15 @@ void RTCStatsCollector::ProduceRTPStreamStats_n(
     // Inbound
     for (const cricket::VoiceReceiverInfo& voice_receiver_info :
          track_media_info_map.voice_media_info()->receivers) {
-      // TODO(nisse): SSRC == 0 currently means none. Delete check when that
+      if (!voice_receiver_info.connected())
-      // is fixed.
-      if (voice_receiver_info.ssrc() == 0)
         continue;
+
       std::unique_ptr<RTCInboundRTPStreamStats> inbound_audio(
           new RTCInboundRTPStreamStats(RTCInboundRTPStreamStatsIDFromSSRC(
                                            true, voice_receiver_info.ssrc()),
                                        timestamp_us));
-      SetInboundRTPStreamStatsFromVoiceReceiverInfo(
+      SetInboundRTPStreamStatsFromVoiceReceiverInfo(voice_receiver_info,
-          voice_receiver_info, inbound_audio.get());
+                                                    inbound_audio.get());
       // TODO(hta): This lookup should look for the sender, not the track.
       rtc::scoped_refptr<AudioTrackInterface> audio_track =
           track_media_info_map_->GetAudioTrack(voice_receiver_info);
@@ -1045,9 +1053,7 @@ void RTCStatsCollector::ProduceRTPStreamStats_n(
     // Outbound
     for (const cricket::VoiceSenderInfo& voice_sender_info :
          track_media_info_map.voice_media_info()->senders) {
-      // TODO(nisse): SSRC == 0 currently means none. Delete check when that
+      if (!voice_sender_info.connected())
-      // is fixed.
-      if (voice_sender_info.ssrc() == 0)
         continue;
       std::unique_ptr<RTCOutboundRTPStreamStats> outbound_audio(
           new RTCOutboundRTPStreamStats(
@@ -1081,7 +1087,7 @@ void RTCStatsCollector::ProduceRTPStreamStats_n(
          track_media_info_map.video_media_info()->receivers) {
       // TODO(nisse): SSRC == 0 currently means none. Delete check when that
       // is fixed.
-      if (video_receiver_info.ssrc() == 0)
+      if (!video_receiver_info.connected())
         continue;
       std::unique_ptr<RTCInboundRTPStreamStats> inbound_video(
           new RTCInboundRTPStreamStats(
@@ -1105,9 +1111,7 @@ void RTCStatsCollector::ProduceRTPStreamStats_n(
     // Outbound
     for (const cricket::VideoSenderInfo& video_sender_info :
          track_media_info_map.video_media_info()->senders) {
-      // TODO(nisse): SSRC == 0 currently means none. Delete check when that
+      if (!video_sender_info.connected())
-      // is fixed.
-      if (video_sender_info.ssrc() == 0)
         continue;
       std::unique_ptr<RTCOutboundRTPStreamStats> outbound_video(
           new RTCOutboundRTPStreamStats(RTCOutboundRTPStreamStatsIDFromSSRC(

pc/rtcstatscollector_unittest.cc

@@ -2397,8 +2397,8 @@ TEST_F(RTCStatsCollectorTest, CollectNoStreamRTCOutboundRTPStreamStats_Audio) {
 
 // When the PC has not had SetLocalDescription done, tracks all have
 // SSRC 0, meaning "unconnected".
-// We do not report stats on those tracks. https://bugs.webrtc.org/8673
+// In this state, we report on track stats, but not RTP stats.
-TEST_F(RTCStatsCollectorTest, StatsNotReportedOnZeroSsrc) {
+TEST_F(RTCStatsCollectorTest, StatsReportedOnZeroSsrc) {
   rtc::scoped_refptr<MediaStreamTrackInterface> track =
       CreateFakeTrack(cricket::MEDIA_TYPE_AUDIO, "audioTrack",
                       MediaStreamTrackInterface::kLive);
@@ -2410,7 +2410,10 @@ TEST_F(RTCStatsCollectorTest, StatsNotReportedOnZeroSsrc) {
   rtc::scoped_refptr<const RTCStatsReport> report = GetStatsReport();
   std::vector<const RTCMediaStreamTrackStats*> track_stats =
       report->GetStatsOfType<RTCMediaStreamTrackStats>();
-  EXPECT_EQ(0, track_stats.size());
+  EXPECT_EQ(1, track_stats.size());
+  std::vector<const RTCRTPStreamStats*> rtp_stream_stats =
+      report->GetStatsOfType<RTCRTPStreamStats>();
+  EXPECT_EQ(0, rtp_stream_stats.size());
 }
 
 class RTCStatsCollectorTestWithFakeCollector : public testing::Test {