Implement the NackModule as part of the new jitter buffer.

webrtc/modules/video_coding/histogram_unittest.cc

+/*
+ *  Copyright (c) 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.
+ */
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/modules/video_coding/histogram.h"
+
+namespace webrtc {
+namespace video_coding {
+
+class TestHistogram : public ::testing::Test {
+ protected:
+  TestHistogram() : histogram_(5, 10) {}
+  Histogram histogram_;
+};
+
+TEST_F(TestHistogram, NumValues) {
+  EXPECT_EQ(0ul, histogram_.NumValues());
+  histogram_.Add(0);
+  EXPECT_EQ(1ul, histogram_.NumValues());
+}
+
+TEST_F(TestHistogram, InverseCdf) {
+  histogram_.Add(0);
+  histogram_.Add(1);
+  histogram_.Add(2);
+  histogram_.Add(3);
+  histogram_.Add(4);
+  EXPECT_EQ(5ul, histogram_.NumValues());
+  EXPECT_EQ(1ul, histogram_.InverseCdf(0.2f));
+  EXPECT_EQ(2ul, histogram_.InverseCdf(0.2000001f));
+  EXPECT_EQ(4ul, histogram_.InverseCdf(0.8f));
+
+  histogram_.Add(0);
+  EXPECT_EQ(6ul, histogram_.NumValues());
+  EXPECT_EQ(1ul, histogram_.InverseCdf(0.2f));
+  EXPECT_EQ(1ul, histogram_.InverseCdf(0.2000001f));
+}
+
+TEST_F(TestHistogram, ReplaceOldValues) {
+  histogram_.Add(0);
+  histogram_.Add(0);
+  histogram_.Add(0);
+  histogram_.Add(0);
+  histogram_.Add(0);
+  histogram_.Add(1);
+  histogram_.Add(1);
+  histogram_.Add(1);
+  histogram_.Add(1);
+  histogram_.Add(1);
+  EXPECT_EQ(10ul, histogram_.NumValues());
+  EXPECT_EQ(1ul, histogram_.InverseCdf(0.5f));
+  EXPECT_EQ(2ul, histogram_.InverseCdf(0.5000001f));
+
+  histogram_.Add(4);
+  histogram_.Add(4);
+  histogram_.Add(4);
+  histogram_.Add(4);
+  EXPECT_EQ(10ul, histogram_.NumValues());
+  EXPECT_EQ(1ul, histogram_.InverseCdf(0.1f));
+  EXPECT_EQ(2ul, histogram_.InverseCdf(0.5f));
+
+  histogram_.Add(20);
+  EXPECT_EQ(10ul, histogram_.NumValues());
+  EXPECT_EQ(2ul, histogram_.InverseCdf(0.5f));
+  EXPECT_EQ(5ul, histogram_.InverseCdf(0.5000001f));
+}
+
+}  // namespace video_coding
+}  // namespace webrtc