Report max interframe delay over window insdead of interframe delay sum

webrtc/video/receive_statistics_proxy.h

Index: webrtc/video/receive_statistics_proxy.h
diff --git a/webrtc/video/receive_statistics_proxy.h b/webrtc/video/receive_statistics_proxy.h
index 8aff1a254c47ec6c79f50696cb13009350822d98..09ffdc0debf6ac26c1ce52fb59c18876700aa702 100644
--- a/webrtc/video/receive_statistics_proxy.h
+++ b/webrtc/video/receive_statistics_proxy.h
@@ -11,8 +11,10 @@
 #ifndef WEBRTC_VIDEO_RECEIVE_STATISTICS_PROXY_H_
 #define WEBRTC_VIDEO_RECEIVE_STATISTICS_PROXY_H_
 
+#include <deque>
 #include <map>
 #include <string>
+#include <utility>
 
 #include "webrtc/common_types.h"
 #include "webrtc/common_video/include/frame_callback.h"
@@ -103,6 +105,27 @@ class ReceiveStatisticsProxy : public VCMReceiveStatisticsCallback,
   struct QpCounters {
     SampleCounter vp8;
   };
+  // |time_ms| should never decrease in consecutive calls to Add and MovingMax
+  // as if it's local time. Not thread-safe.
+  class MovingMaxCounter {
+   public:
+    explicit MovingMaxCounter(int window_length_ms) :
+      window_length_ms_(window_length_ms) {}
+    void Add(int sample, int64_t time_ms);
+    // Returns max sample in window given current time.
+    // Can be sped-up in case when MovingMax is called many times in a row
+    // without new elements added (not likely case currently) by removing
+    // obsolete elements from the beginning of the deque instead of skipping
+    // them. In that case deque should be marked as mutable.
+    rtc::Optional<int> MovingMax(int64_t time_ms) const;
+    void Reset();
+   private:
+    int window_length_ms_;
+    // Samples in the window are stored as pairs <time, sample> in this deque in
+    // chronological order. Samples what can't be maximum in any window are
+    // thrown out - deque always contain decreasing sequence of samples.
+    std::deque <std::pair<int64_t, int>> samples_;
+  };

[sprang_webrtc, 2017/08/18 09:06:49]

Interesting class. If no equivalent is available in rtc base, maybe you should
move it there and templetize it?
That would also make it easier to test this logic independently.

[ilnik, 2017/08/18 11:43:01]

Done.

 
   void UpdateHistograms() EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
@@ -152,6 +175,7 @@ class ReceiveStatisticsProxy : public VCMReceiveStatisticsCallback,
   int64_t e2e_delay_max_ms_screenshare_ GUARDED_BY(crit_);
   int64_t interframe_delay_max_ms_video_  GUARDED_BY(crit_);
   int64_t interframe_delay_max_ms_screenshare_  GUARDED_BY(crit_);
+  MovingMaxCounter interframe_delay_max_moving_  GUARDED_BY(crit_);
   MaxCounter freq_offset_counter_ GUARDED_BY(crit_);
   int64_t first_report_block_time_ms_ GUARDED_BY(crit_);
   ReportBlockStats report_block_stats_ GUARDED_BY(crit_);