Refactor DelayManager into separate Histogram class and make it injectable for testing purposes.
Change-Id: I98aa3f992169e598fc1a3dd850400183395fe1fe
Bug: webrtc:10333
Reviewed-on: https://webrtc-review.googlesource.com/c/123445
Commit-Queue: Jakob Ivarsson‎ <jakobi@webrtc.org>
Reviewed-by: Minyue Li <minyue@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26797}diff --git a/modules/audio_coding/neteq/histogram_unittest.cc b/modules/audio_coding/neteq/histogram_unittest.cc
new file mode 100644
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+++ b/modules/audio_coding/neteq/histogram_unittest.cc
@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2019 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 <cmath>
+
+#include "modules/audio_coding/neteq/histogram.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+
+TEST(HistogramTest, Initialization) {
+ Histogram histogram(65, 32440);
+ histogram.Reset();
+ const auto& buckets = histogram.buckets();
+ double sum = 0.0;
+ for (size_t i = 0; i < buckets.size(); i++) {
+ EXPECT_NEAR(ldexp(std::pow(0.5, static_cast<int>(i + 1)), 30), buckets[i],
+ 65537);
+ // Tolerance 65537 in Q30 corresponds to a delta of approximately 0.00006.
+ sum += buckets[i];
+ }
+ EXPECT_EQ(1 << 30, static_cast<int>(sum)); // Should be 1 in Q30.
+}
+
+TEST(HistogramTest, Add) {
+ Histogram histogram(10, 32440);
+ histogram.Reset();
+ const std::vector<int> before = histogram.buckets();
+ const int index = 5;
+ histogram.Add(index);
+ const std::vector<int> after = histogram.buckets();
+ EXPECT_GT(after[index], before[index]);
+ int sum = 0;
+ for (int bucket : after) {
+ sum += bucket;
+ }
+ EXPECT_EQ(1 << 30, sum);
+}
+
+TEST(HistogramTest, ForgetFactor) {
+ Histogram histogram(10, 32440);
+ histogram.Reset();
+ const std::vector<int> before = histogram.buckets();
+ const int index = 4;
+ histogram.Add(index);
+ const std::vector<int> after = histogram.buckets();
+ for (int i = 0; i < histogram.NumBuckets(); ++i) {
+ if (i != index) {
+ EXPECT_LT(after[i], before[i]);
+ }
+ }
+}
+
+// Test if the histogram is scaled correctly if the bucket width is decreased.
+TEST(HistogramTest, DownScale) {
+ // Test a straightforward 60 to 20 change.
+ std::vector<int> buckets = {12, 0, 0, 0, 0, 0};
+ std::vector<int> expected_result = {4, 4, 4, 0, 0, 0};
+ std::vector<int> stretched_buckets = Histogram::ScaleBuckets(buckets, 60, 20);
+ EXPECT_EQ(stretched_buckets, expected_result);
+
+ // Test an example where the last bin in the stretched histogram should
+ // contain the sum of the elements that don't fit into the new histogram.
+ buckets = {18, 15, 12, 9, 6, 3, 0};
+ expected_result = {6, 6, 6, 5, 5, 5, 30};
+ stretched_buckets = Histogram::ScaleBuckets(buckets, 60, 20);
+ EXPECT_EQ(stretched_buckets, expected_result);
+
+ // Test a 120 to 60 change.
+ buckets = {18, 16, 14, 4, 0};
+ expected_result = {9, 9, 8, 8, 18};
+ stretched_buckets = Histogram::ScaleBuckets(buckets, 120, 60);
+ EXPECT_EQ(stretched_buckets, expected_result);
+
+ // Test a 120 to 20 change.
+ buckets = {19, 12, 0, 0, 0, 0, 0, 0};
+ expected_result = {3, 3, 3, 3, 3, 3, 2, 11};
+ stretched_buckets = Histogram::ScaleBuckets(buckets, 120, 20);
+ EXPECT_EQ(stretched_buckets, expected_result);
+
+ // Test a 70 to 40 change.
+ buckets = {13, 7, 5, 3, 1, 5, 12, 11, 3, 0, 0, 0};
+ expected_result = {7, 5, 5, 3, 3, 2, 2, 1, 2, 2, 6, 22};
+ stretched_buckets = Histogram::ScaleBuckets(buckets, 70, 40);
+ EXPECT_EQ(stretched_buckets, expected_result);
+
+ // Test a 30 to 20 change.
+ buckets = {13, 7, 5, 3, 1, 5, 12, 11, 3, 0, 0, 0};
+ expected_result = {8, 6, 6, 3, 2, 2, 1, 3, 3, 8, 7, 11};
+ stretched_buckets = Histogram::ScaleBuckets(buckets, 30, 20);
+ EXPECT_EQ(stretched_buckets, expected_result);
+}
+
+// Test if the histogram is scaled correctly if the bucket width is increased.
+TEST(HistogramTest, UpScale) {
+ // Test a 20 to 60 change.
+ std::vector<int> buckets = {12, 11, 10, 3, 2, 1};
+ std::vector<int> expected_result = {33, 6, 0, 0, 0, 0};
+ std::vector<int> compressed_buckets =
+ Histogram::ScaleBuckets(buckets, 20, 60);
+ EXPECT_EQ(compressed_buckets, expected_result);
+
+ // Test a 60 to 120 change.
+ buckets = {18, 16, 14, 4, 1};
+ expected_result = {34, 18, 1, 0, 0};
+ compressed_buckets = Histogram::ScaleBuckets(buckets, 60, 120);
+ EXPECT_EQ(compressed_buckets, expected_result);
+
+ // Test a 20 to 120 change.
+ buckets = {18, 12, 5, 4, 4, 3, 5, 1};
+ expected_result = {46, 6, 0, 0, 0, 0, 0, 0};
+ compressed_buckets = Histogram::ScaleBuckets(buckets, 20, 120);
+ EXPECT_EQ(compressed_buckets, expected_result);
+
+ // Test a 70 to 80 change.
+ buckets = {13, 7, 5, 3, 1, 5, 12, 11, 3};
+ expected_result = {11, 8, 6, 2, 5, 12, 13, 3, 0};
+ compressed_buckets = Histogram::ScaleBuckets(buckets, 70, 80);
+ EXPECT_EQ(compressed_buckets, expected_result);
+
+ // Test a 50 to 110 change.
+ buckets = {13, 7, 5, 3, 1, 5, 12, 11, 3};
+ expected_result = {18, 8, 16, 16, 2, 0, 0, 0, 0};
+ compressed_buckets = Histogram::ScaleBuckets(buckets, 50, 110);
+ EXPECT_EQ(compressed_buckets, expected_result);
+}
+
+// Test if the histogram scaling function handles overflows correctly.
+TEST(HistogramTest, OverflowTest) {
+ // Test a upscale operation that can cause overflow.
+ std::vector<int> buckets = {733544448, 0, 0, 0, 0, 0, 0,
+ 340197376, 0, 0, 0, 0, 0, 0};
+ std::vector<int> expected_result = {733544448, 340197376, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0};
+ std::vector<int> scaled_buckets = Histogram::ScaleBuckets(buckets, 10, 60);
+ EXPECT_EQ(scaled_buckets, expected_result);
+
+ buckets = {655591163, 39962288, 360736736, 1930514, 4003853, 1782764,
+ 114119, 2072996, 0, 2149354, 0};
+ expected_result = {1056290187, 7717131, 2187115, 2149354, 0, 0,
+ 0, 0, 0, 0, 0};
+ scaled_buckets = Histogram::ScaleBuckets(buckets, 20, 60);
+ EXPECT_EQ(scaled_buckets, expected_result);
+
+ // In this test case we will not be able to add everything to the final bin in
+ // the scaled histogram. Check that the last bin doesn't overflow.
+ buckets = {2000000000, 2000000000, 2000000000,
+ 2000000000, 2000000000, 2000000000};
+ expected_result = {666666666, 666666666, 666666666,
+ 666666667, 666666667, 2147483647};
+ scaled_buckets = Histogram::ScaleBuckets(buckets, 60, 20);
+ EXPECT_EQ(scaled_buckets, expected_result);
+
+ // In this test case we will not be able to add enough to each of the bins,
+ // so the values should be smeared out past the end of the normal range.
+ buckets = {2000000000, 2000000000, 2000000000,
+ 2000000000, 2000000000, 2000000000};
+ expected_result = {2147483647, 2147483647, 2147483647,
+ 2147483647, 2147483647, 1262581765};
+ scaled_buckets = Histogram::ScaleBuckets(buckets, 20, 60);
+ EXPECT_EQ(scaled_buckets, expected_result);
+}
+
+} // namespace webrtc