Report max interframe delay over window insdead of interframe delay sum

webrtc/video/receive_statistics_proxy_unittest.cc

 /*
  *  Copyright 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 80 matching lines @@
   EXPECT_EQ(rtc::Optional<uint64_t>(), statistics_proxy_->GetStats().qp_sum);
   statistics_proxy_->OnDecodedFrame(rtc::Optional<uint8_t>(3u),
                                     VideoContentType::UNSPECIFIED);
   EXPECT_EQ(rtc::Optional<uint64_t>(3u), statistics_proxy_->GetStats().qp_sum);
   statistics_proxy_->OnDecodedFrame(rtc::Optional<uint8_t>(127u),
                                     VideoContentType::UNSPECIFIED);
   EXPECT_EQ(rtc::Optional<uint64_t>(130u),
             statistics_proxy_->GetStats().qp_sum);
 }
 
-TEST_F(ReceiveStatisticsProxyTest,
-       OnDecodedFrameIncreasesInterframeDelayMsSum) {
-  const uint64_t kInterframeDelayMs1 = 100;
-  const uint64_t kInterframeDelayMs2 = 200;
-  EXPECT_EQ(0u, statistics_proxy_->GetStats().interframe_delay_sum_ms);
+TEST_F(ReceiveStatisticsProxyTest, ReportsMaxInterframeDelay) {
+  const int64_t kInterframeDelayMs1 = 100;
+  const int64_t kInterframeDelayMs2 = 200;
+  const int64_t kInterframeDelayMs3 = 100;
+  EXPECT_EQ(-1, statistics_proxy_->GetStats().interframe_delay_max_ms);
   statistics_proxy_->OnDecodedFrame(rtc::Optional<uint8_t>(3u),
                                     VideoContentType::UNSPECIFIED);
-  EXPECT_EQ(0u, statistics_proxy_->GetStats().interframe_delay_sum_ms);
+  EXPECT_EQ(-1, statistics_proxy_->GetStats().interframe_delay_max_ms);
 
   fake_clock_.AdvanceTimeMilliseconds(kInterframeDelayMs1);
   statistics_proxy_->OnDecodedFrame(rtc::Optional<uint8_t>(127u),
                                     VideoContentType::UNSPECIFIED);
   EXPECT_EQ(kInterframeDelayMs1,
-            statistics_proxy_->GetStats().interframe_delay_sum_ms);
+            statistics_proxy_->GetStats().interframe_delay_max_ms);
 
   fake_clock_.AdvanceTimeMilliseconds(kInterframeDelayMs2);
   statistics_proxy_->OnDecodedFrame(rtc::Optional<uint8_t>(127u),
                                     VideoContentType::UNSPECIFIED);
-  EXPECT_EQ(kInterframeDelayMs1 + kInterframeDelayMs2,
-            statistics_proxy_->GetStats().interframe_delay_sum_ms);
+  EXPECT_EQ(kInterframeDelayMs2,
+            statistics_proxy_->GetStats().interframe_delay_max_ms);
+
+  fake_clock_.AdvanceTimeMilliseconds(kInterframeDelayMs3);
+  statistics_proxy_->OnDecodedFrame(rtc::Optional<uint8_t>(127u),
+                                    VideoContentType::UNSPECIFIED);
+  // kInterframeDelayMs3 is smaller than kInterframeDelayMs2.
+  EXPECT_EQ(kInterframeDelayMs2,
+            statistics_proxy_->GetStats().interframe_delay_max_ms);
+}
+
+TEST_F(ReceiveStatisticsProxyTest, ReportInterframeDelayInWindow) {
+  const int64_t kInterframeDelayMs1 = 9000;
+  const int64_t kInterframeDelayMs2 = 7500;
+  const int64_t kInterframeDelayMs3 = 7000;
+  EXPECT_EQ(-1, statistics_proxy_->GetStats().interframe_delay_max_ms);
+  statistics_proxy_->OnDecodedFrame(rtc::Optional<uint8_t>(3u),
+                                    VideoContentType::UNSPECIFIED);
+  EXPECT_EQ(-1, statistics_proxy_->GetStats().interframe_delay_max_ms);
+
+  fake_clock_.AdvanceTimeMilliseconds(kInterframeDelayMs1);
+  statistics_proxy_->OnDecodedFrame(rtc::Optional<uint8_t>(127u),
+                                    VideoContentType::UNSPECIFIED);
+  EXPECT_EQ(kInterframeDelayMs1,
+            statistics_proxy_->GetStats().interframe_delay_max_ms);
+
+  fake_clock_.AdvanceTimeMilliseconds(kInterframeDelayMs2);
+  statistics_proxy_->OnDecodedFrame(rtc::Optional<uint8_t>(127u),
+                                    VideoContentType::UNSPECIFIED);
+  // Still first delay is the maximum
+  EXPECT_EQ(kInterframeDelayMs1,
+            statistics_proxy_->GetStats().interframe_delay_max_ms);
+
+  fake_clock_.AdvanceTimeMilliseconds(kInterframeDelayMs3);
+  statistics_proxy_->OnDecodedFrame(rtc::Optional<uint8_t>(127u),
+                                    VideoContentType::UNSPECIFIED);
+  // Now the first sample is out of the window, so the second is the maximum.
+  EXPECT_EQ(kInterframeDelayMs2,
+            statistics_proxy_->GetStats().interframe_delay_max_ms);
 }
 
 TEST_F(ReceiveStatisticsProxyTest, OnDecodedFrameWithoutQpQpSumWontExist) {
   EXPECT_EQ(rtc::Optional<uint64_t>(), statistics_proxy_->GetStats().qp_sum);
   statistics_proxy_->OnDecodedFrame(rtc::Optional<uint8_t>(),
                                     VideoContentType::UNSPECIFIED);
   EXPECT_EQ(rtc::Optional<uint64_t>(), statistics_proxy_->GetStats().qp_sum);
 }
 
 TEST_F(ReceiveStatisticsProxyTest, OnDecodedFrameWithoutQpResetsQpSum) {
@@ skipping 642 matching lines @@
   statistics_proxy_.reset();
   EXPECT_EQ(0, metrics::NumSamples("WebRTC.Video.InterframeDelayInMs"));
   EXPECT_EQ(0, metrics::NumSamples("WebRTC.Video.InterframeDelayMaxInMs"));
   EXPECT_EQ(
       0, metrics::NumSamples("WebRTC.Video.Screenshare.InterframeDelayInMs"));
   EXPECT_EQ(0, metrics::NumSamples(
                    "WebRTC.Video.Screenshare.InterframeDelayMaxInMs"));
 }
 
 }  // namespace webrtc