Get VideoCapturer stats via VideoTrackSourceInterface in StatsCollector,

webrtc/api/statscollector.cc

Index: webrtc/api/statscollector.cc
diff --git a/webrtc/api/statscollector.cc b/webrtc/api/statscollector.cc
index d77953b3bed1d49bb75a3be6a35c5d10f91c382b..1711c469996f35c2c1996fce8e950ea086dea263 100644
--- a/webrtc/api/statscollector.cc
+++ b/webrtc/api/statscollector.cc
@@ -236,11 +236,9 @@ void ExtractStats(const cricket::VideoSenderInfo& info, StatsReport* report) {
     { StatsReport::kStatsValueNameEncodeUsagePercent,
       info.encode_usage_percent },
     { StatsReport::kStatsValueNameFirsReceived, info.firs_rcvd },
-    { StatsReport::kStatsValueNameFrameHeightInput, info.input_frame_height },
     { StatsReport::kStatsValueNameFrameHeightSent, info.send_frame_height },
     { StatsReport::kStatsValueNameFrameRateInput, info.framerate_input },
     { StatsReport::kStatsValueNameFrameRateSent, info.framerate_sent },
-    { StatsReport::kStatsValueNameFrameWidthInput, info.input_frame_width },
     { StatsReport::kStatsValueNameFrameWidthSent, info.send_frame_width },
     { StatsReport::kStatsValueNameNacksReceived, info.nacks_rcvd },
     { StatsReport::kStatsValueNamePacketsLost, info.packets_lost },
@@ -474,6 +472,7 @@ StatsCollector::UpdateStats(PeerConnectionInterface::StatsOutputLevel level) {
     ExtractSessionInfo();
     ExtractVoiceInfo();
     ExtractVideoInfo(level);
+    ExtractCapturerInfo();
     ExtractDataInfo();
     UpdateTrackReports();
   }
@@ -828,6 +827,26 @@ void StatsCollector::ExtractVideoInfo(
   }
 }
 
+void StatsCollector::ExtractCapturerInfo() {
+  RTC_DCHECK(pc_->session()->signaling_thread()->IsCurrent());
+
+  rtc::scoped_refptr<StreamCollectionInterface> streams = pc_->local_streams();
+  for (size_t i = 0; i < streams->count(); i++) {
+    for (auto track : streams->at(i)->GetVideoTracks()) {
+      VideoTrackSourceInterface* source = track->GetSource();
+      VideoTrackSourceInterface::VideoSourceInfo info;
+      if (source->GetInfo(&info)) {
+        // TODO(nisse): What id to use???

[pthatcher1, 2016/03/24 18:10:25]

Based on the code here:

https://code.google.com/p/chromium/codesearch#chromium/src/third_party/webrtc...

The ID should be:

StatsReport::NewIdWithDirection(StatsReport::kStatsReportTypeSsrc,
rtc::ToString<uint32_t>(ssrc), StatsReport::kSend)

But to know the SSRC, you need to know the RtpSender object instead of the
StreamCollectionInterface, like so:

for (rtc::scoped_refptr<RtpSenderInterface> sender : pc_->GetSenders()) {
  uint32_t ssrc = sender->ssrc();
  rtc::scoped_refptr<MediaStreamTrackInterface> track = sender->track();
  if (!track || sender->track()->kind() !=
MediaStreamTrackInterface::kVideoKind) {
    continue;
  }
  StatsReport::Id stats_id =
StatsReport::NewIdWithDirection(StatsReport::kStatsReportTypeSsrc,
rtc::ToString<uint32_t>(ssrc), StatsReport::kSend);

  track->GetSource()->GetInfo(&info);
  ...
}



Now, there's just one problem:  RtpSender::GetTrack is a
MediaStreamTrackInterface, not a VideoTrackSourceInterface.


Have you considered moving this code to RtpSender by implementing an
RtpSender::GetStats?  That way you could do this:

sender->GetStats(&report);


And then the sender could do report->AddInt(...), etc.  In fact, it might be
worth moving the logic for the stats_id to the sender as well so that you would
just have:

for (rtc::scoped_refptr<RtpSenderInterface> sender : pc_->GetSenders()) {
  StatsReport* report = report_.FindOrAddNew(sender->stats_id());
  sender->GetStats(&report);
}

And you'd be done.

[nisse-webrtc, 2016/03/29 08:36:32]

Nice idea. I implemented that. A few questions: 

Do we really want to use StatsReport directly outside of the StatsCollector?
That seems like the most reasonable way if we want to provide some other stats
for AudioRtpSender. I named the RtpSender method ReportStats rather then
GetStats because I think the latter name is more appropriate for a method
populating a simple struct with values.

Do we need any synchronization in VideoRtpSender? Or is all relevant code
running on the same thread?

The current version will produce empty reports in some cases. E.g., if track_ is
NULL, or if GetSource()->GetStats(&stats) returns false (happens for remote
sources), VideoRtpSender::stats_id returns non-NULL, but ReportStats doesn't
fill out any values. To get that right, it would be nice with a single method
producing either both the id and the report, or nothing, but that collides a bit
with the use of FindOrAddNew. Not sure if it matters, maybe empty reports are
pruned later anyway?

+        StatsReport* report = reports_.FindOrAddNew(StatsReport::Id());
+        report->AddInt(StatsReport::kStatsValueNameFrameWidthInput,
+                       info.input_width);
+        report->AddInt(StatsReport::kStatsValueNameFrameHeightInput,
+                       info.input_height);
+      }
+    }
+  }
+}
+
 void StatsCollector::ExtractDataInfo() {
   RTC_DCHECK(pc_->session()->signaling_thread()->IsCurrent());