Add stats (histograms) for vp8 screenshare layers

webrtc/modules/video_coding/codecs/vp8/screenshare_layers.cc

Index: webrtc/modules/video_coding/codecs/vp8/screenshare_layers.cc
diff --git a/webrtc/modules/video_coding/codecs/vp8/screenshare_layers.cc b/webrtc/modules/video_coding/codecs/vp8/screenshare_layers.cc
index 2480a502e8e02ed92ce79fbfa1f0c51b86b4a5cb..869657b972d08ca795794d0d4cec7a6e2824bbc9 100644
--- a/webrtc/modules/video_coding/codecs/vp8/screenshare_layers.cc
+++ b/webrtc/modules/video_coding/codecs/vp8/screenshare_layers.cc
@@ -17,6 +17,8 @@
 #include "vpx/vpx_encoder.h"
 #include "vpx/vp8cx.h"
 #include "webrtc/modules/video_coding/include/video_codec_interface.h"
+#include "webrtc/system_wrappers/include/clock.h"
+#include "webrtc/system_wrappers/include/metrics.h"
 
 namespace webrtc {
 
@@ -46,8 +48,10 @@ const int ScreenshareLayers::kTl1SyncFlags =
     VP8_EFLAG_NO_UPD_LAST;
 
 ScreenshareLayers::ScreenshareLayers(int num_temporal_layers,
-                                     uint8_t initial_tl0_pic_idx)
-    : number_of_temporal_layers_(num_temporal_layers),
+                                     uint8_t initial_tl0_pic_idx,
+                                     Clock* clock)
+    : clock_(clock),
+      number_of_temporal_layers_(num_temporal_layers),
       last_base_layer_sync_(false),
       tl0_pic_idx_(initial_tl0_pic_idx),
       active_layer_(-1),
@@ -61,6 +65,10 @@ ScreenshareLayers::ScreenshareLayers(int num_temporal_layers,
   RTC_CHECK_LE(num_temporal_layers, 2);
 }
 
+ScreenshareLayers::~ScreenshareLayers() {
+  UpdateHistograms();
+}
+
 int ScreenshareLayers::CurrentLayerId() const {
   // Codec does not use temporal layers for screenshare.
   return 0;
@@ -72,6 +80,9 @@ int ScreenshareLayers::EncodeFlags(uint32_t timestamp) {
     return 0;
   }
 
+  if (stats_.first_frame_time_ms_ == -1)
+    stats_.first_frame_time_ms_ = clock_->TimeInMilliseconds();
+
   int64_t unwrapped_timestamp = time_wrap_handler_.Unwrap(timestamp);
   int flags = 0;
 
@@ -104,6 +115,7 @@ int ScreenshareLayers::EncodeFlags(uint32_t timestamp) {
       break;
     case -1:
       flags = -1;
+      ++stats_.num_dropped_frames_;
       break;
     default:
       flags = -1;
@@ -176,6 +188,7 @@ void ScreenshareLayers::FrameEncoded(unsigned int size,
   RTC_DCHECK_NE(-1, active_layer_);
   if (size == 0) {
     layers_[active_layer_].state = TemporalLayer::State::kDropped;
+    ++stats_.num_overshoots_;
     return;
   }
 
@@ -189,8 +202,14 @@ void ScreenshareLayers::FrameEncoded(unsigned int size,
   if (active_layer_ == 0) {
     layers_[0].debt_bytes_ += size;
     layers_[1].debt_bytes_ += size;
+    ++stats_.num_tl0_frames_;
+    stats_.tl0_target_bitrate_sum_ += layers_[0].target_rate_kbps_;
+    stats_.tl0_qp_sum_ += qp;
   } else if (active_layer_ == 1) {
     layers_[1].debt_bytes_ += size;
+    ++stats_.num_tl1_frames_;
+    stats_.tl1_target_bitrate_sum_ += layers_[1].target_rate_kbps_;
+    stats_.tl1_qp_sum_ += qp;
   }
 }
 
@@ -283,4 +302,42 @@ void ScreenshareLayers::TemporalLayer::UpdateDebt(int64_t delta_ms) {
   }
 }
 
+void ScreenshareLayers::UpdateHistograms() {
+  if (stats_.first_frame_time_ms_ == -1)
+    return;
+  int64_t duration_sec =
+      (clock_->TimeInMilliseconds() - stats_.first_frame_time_ms_ + 500) / 1000;
+  if (duration_sec >= metrics::kMinRunTimeInSeconds) {
+    RTC_HISTOGRAM_COUNTS_10000(
+        "WebRTC.Video.Screenshare.Layer0.FrameRate",
+        (stats_.num_tl0_frames_ + (duration_sec / 2)) / duration_sec);
+    RTC_HISTOGRAM_COUNTS_10000(
+        "WebRTC.Video.Screenshare.Layer1.FrameRate",
+        (stats_.num_tl1_frames_ + (duration_sec / 2)) / duration_sec);
+    int total_frames = stats_.num_tl0_frames_ + stats_.num_tl1_frames_;
+    RTC_HISTOGRAM_COUNTS_10000("WebRTC.Video.Screenshare.FramesPerDrop",
+                               stats_.num_dropped_frames_ == 0
+                                   ? 0
+                                   : total_frames / stats_.num_dropped_frames_);
+    RTC_HISTOGRAM_COUNTS_10000("WebRTC.Video.Screenshare.FramesPerOvershoot",
+                               stats_.num_overshoots_ == 0
+                                   ? 0
+                                   : total_frames / stats_.num_overshoots_);
+    if (stats_.num_tl0_frames_ > 0) {
+      RTC_HISTOGRAM_COUNTS_10000("WebRTC.Video.Screenshare.Layer0.Qp",
+                                 stats_.tl0_qp_sum_ / stats_.num_tl0_frames_);
+      RTC_HISTOGRAM_COUNTS_10000(
+          "WebRTC.Video.Screenshare.Layer0.TargetBitrate",
+          stats_.tl0_target_bitrate_sum_ / stats_.num_tl0_frames_);
+    }
+    if (stats_.num_tl1_frames_ > 0) {
+      RTC_HISTOGRAM_COUNTS_10000("WebRTC.Video.Screenshare.Layer1.Qp",
+                                 stats_.tl1_qp_sum_ / stats_.num_tl1_frames_);
+      RTC_HISTOGRAM_COUNTS_10000(
+          "WebRTC.Video.Screenshare.Layer1.TargetBitrate",
+          stats_.tl1_target_bitrate_sum_ / stats_.num_tl1_frames_);
+    }
+  }
+}
+
 }  // namespace webrtc