Add histogram for percentage of sent frames that are limited in resolution due to bandwidth.

webrtc/video/send_statistics_proxy.cc

Index: webrtc/video/send_statistics_proxy.cc
diff --git a/webrtc/video/send_statistics_proxy.cc b/webrtc/video/send_statistics_proxy.cc
index 551b4b562a43904f6cfe1105d65455b2610126b9..4057f700a7e8a0a27ef20bc1bed701557d623831 100644
--- a/webrtc/video/send_statistics_proxy.cc
+++ b/webrtc/video/send_statistics_proxy.cc
@@ -62,6 +62,12 @@ void SendStatisticsProxy::UpdateHistograms() {
   int encode_ms = encode_time_counter_.Avg(kMinRequiredSamples);
   if (encode_ms != -1)
     RTC_HISTOGRAM_COUNTS_1000("WebRTC.Video.EncodeTimeInMs", encode_ms);
+
+  int bw_limited = bw_limited_sent_frame_counter_.Percent(kMinRequiredSamples);
+  if (bw_limited != -1) {
+    RTC_HISTOGRAM_PERCENTAGE("WebRTC.Video.BandwidthLimitedResolutionInPercent",

[pbos-webrtc, 2015/09/11 11:28:23]

Can we report this per SSRC/simulcast layer? I think the following stats would
be useful:

WebRTC.Video.Simulcast_{0,1,2}.BandwidthLimited...

Because then we can see how often HD is limited, and how often VGA is limited
rather than how often any of them are limited.

[stefan-webrtc, 2015/09/16 07:49:27]

It doesn't scale very well, and as we make simulcast more general this may
become a problem, but it could be worth ignoring that issue for now if we think
tracking per layer is important.

I was thinking that we could track the number of resolutions we disable. Not the
same thing though.

[åsapersson, 2015/09/17 14:12:03]

Added the average number of resolutions disabled when bw limited.

+        bw_limited);
+  }
 }
 
 void SendStatisticsProxy::OutgoingRate(const int video_channel,
@@ -162,6 +168,11 @@ void SendStatisticsProxy::OnSendEncodedImage(
   stats->height = encoded_image._encodedHeight;
   update_times_[ssrc].resolution_update_ms = clock_->TimeInMilliseconds();
 
+  if (encoded_image.adapt_reason_.bw_limited_resolution_available) {
+    bw_limited_sent_frame_counter_.Add(
+        encoded_image.adapt_reason_.bw_limited_resolution);
+  }
+
   // TODO(asapersson): This is incorrect if simulcast layers are encoded on
   // different threads and there is no guarantee that one frame of all layers
   // are encoded before the next start.
@@ -274,4 +285,16 @@ int SendStatisticsProxy::SampleCounter::Avg(int min_required_samples) const {
   return sum / num_samples;
 }
 
+void SendStatisticsProxy::BoolSampleCounter::Add(bool sample) {
+  if (sample)
+    ++sum;
+  ++num_samples;
+}
+
+int SendStatisticsProxy::BoolSampleCounter::Percent(
+    int min_required_samples) const {
+  if (num_samples < min_required_samples || num_samples == 0)
+    return -1;
+  return sum * 100 / num_samples;
+}
 }  // namespace webrtc