[Chromecast] Add metrics for logging platform A/V bitrate estimates.

chromecast/media/cma/pipeline/video_pipeline_impl.cc

Index: chromecast/media/cma/pipeline/video_pipeline_impl.cc
diff --git a/chromecast/media/cma/pipeline/video_pipeline_impl.cc b/chromecast/media/cma/pipeline/video_pipeline_impl.cc
index 6b480c62be6bff5df371579f34fe5d16b77d924c..3498d9daf27be91118954b2fe7494ea21b600b43 100644
--- a/chromecast/media/cma/pipeline/video_pipeline_impl.cc
+++ b/chromecast/media/cma/pipeline/video_pipeline_impl.cc
@@ -8,6 +8,8 @@
 #include <utility>
 
 #include "base/bind.h"
+#include "base/time/time.h"
+#include "chromecast/base/metrics/cast_metrics_helper.h"
 #include "chromecast/media/cdm/browser_cdm_cast.h"
 #include "chromecast/media/cma/base/buffering_defs.h"
 #include "chromecast/media/cma/base/cma_logging.h"
@@ -23,6 +25,15 @@ namespace media {
 
 namespace {
 const size_t kMaxVideoFrameSize = 1024 * 1024;
+
+void LogEstimatedVideoBitrate(int bitrate) {
+  CMALOG(kLogControl) << "Estimated video bitrate is " << bitrate << " kbps";
+  chromecast::metrics::CastMetricsHelper* metrics_helper =
+      chromecast::metrics::CastMetricsHelper::GetInstance();
+  metrics_helper->RecordSimpleActionWithValue("Cast.Platform.VideoBitrate",
+                                              bitrate);
+}
+
 }
 
 VideoPipelineImpl::VideoPipelineImpl(
@@ -30,7 +41,10 @@ VideoPipelineImpl::VideoPipelineImpl(
     const VideoPipelineClient& client)
     : AvPipelineImpl(decoder, client.av_pipeline_client),
       video_decoder_(decoder),
-      natural_size_changed_cb_(client.natural_size_changed_cb) {
+      natural_size_changed_cb_(client.natural_size_changed_cb),
+      last_sample_time_(base::Time()),
+      elapsed_time_delta_(base::TimeDelta()),
+      video_bytes_for_bitrate_estimation_(0) {
   DCHECK(video_decoder_);
 }
 
@@ -117,6 +131,25 @@ void VideoPipelineImpl::UpdateStatistics() {
   delta_stats.video_frames_dropped =
       current_stats.video_frames_dropped - previous_stats_.video_frames_dropped;
 
+  base::Time current_time = base::Time::Now();
+  elapsed_time_delta_ += current_time - last_sample_time_;
+  video_bytes_for_bitrate_estimation_ += delta_stats.video_bytes_decoded;
+
+  if (state() != kPlaying) {
+    // Invalidate any data that was collected in a window where we were not in
+    // the playing state.
+    elapsed_time_delta_ = base::TimeDelta::FromSeconds(0);
+    video_bytes_for_bitrate_estimation_ = 0;
+  } else if (elapsed_time_delta_.InMilliseconds() > 5000) {
+    int estimated_bitrate_in_kbps = 8 * video_bytes_for_bitrate_estimation_ /
+                                    elapsed_time_delta_.InMilliseconds();
+    if (estimated_bitrate_in_kbps > 0) {
+      LogEstimatedVideoBitrate(estimated_bitrate_in_kbps);
+    }
+    elapsed_time_delta_ = base::TimeDelta::FromSeconds(0);
+    video_bytes_for_bitrate_estimation_ = 0;
+  }
+  last_sample_time_ = current_time;
   previous_stats_ = current_stats;
 
   client().statistics_cb.Run(delta_stats);