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Fanny LinderborgWebRTC LUCI CQ
Fanny Linderborg
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WebRTC LUCI CQ
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Add support for the Halton sequence
Bug: b/358039777 Change-Id: Id191d584e22cf82384a5d16ed355f41c0bb32b7b Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/358981 Reviewed-by: Erik Språng <[email protected]> Commit-Queue: Fanny Linderborg <[email protected]> Cr-Commit-Position: refs/heads/main@{#42764}
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‎video/BUILD.gn

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@@ -959,6 +959,7 @@ if (rtc_include_tests) {
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"config:encoder_config",
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"config:streams_config",
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"config:video_config_tests",
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"corruption_detection:corruption_detection_tests",
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"//third_party/abseil-cpp/absl/algorithm:container",
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"//third_party/abseil-cpp/absl/functional:any_invocable",
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"//third_party/abseil-cpp/absl/memory",

‎video/corruption_detection/BUILD.gn

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# Copyright 2024 The WebRTC project authors. All rights reserved.
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#
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# Use of this source code is governed by a BSD-style license
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# that can be found in the LICENSE file in the root of the source
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# tree. An additional intellectual property rights grant can be found
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# in the file PATENTS. All contributing project authors may
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# be found in the AUTHORS file in the root of the source tree.
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import("../../webrtc.gni")
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rtc_library("halton_sequence") {
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sources = [
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"halton_sequence.cc",
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"halton_sequence.h",
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]
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deps = [ "../../rtc_base:checks" ]
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}
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if (rtc_include_tests) {
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rtc_library("halton_sequence_unittest") {
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testonly = true
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sources = [ "halton_sequence_unittest.cc" ]
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deps = [
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":halton_sequence",
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"../../test/:test_support",
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]
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}
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rtc_library("corruption_detection_tests") {
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testonly = true
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sources = []
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deps = [ ":halton_sequence_unittest" ]
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}
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}

‎video/corruption_detection/halton_sequence.cc

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/*
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* Copyright 2024 The WebRTC project authors. All rights reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "video/corruption_detection/halton_sequence.h"
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#include <algorithm>
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#include <vector>
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#include "rtc_base/checks.h"
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namespace webrtc {
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namespace {
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static constexpr int kMaxDimensions = 5;
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const int kBases[kMaxDimensions] = {2, 3, 5, 7, 11};
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double GetVanDerCorputSequenceElement(int sequence_idx, int base) {
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if (sequence_idx < 0 || base < 2) {
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sequence_idx = 0;
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base = 2;
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}
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double element = 0.0;
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double positional_value = 1.0;
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int left = sequence_idx;
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while (left > 0) {
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positional_value /= base;
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element += positional_value * (left % base);
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left /= base;
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}
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return element;
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}
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} // namespace
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HaltonSequence::HaltonSequence(int num_dimensions)
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: num_dimensions_(num_dimensions), current_idx_(0) {
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RTC_CHECK_GE(num_dimensions_, 1)
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<< "num_dimensions must be >= 1. Will be set to 1.";
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RTC_CHECK_LE(num_dimensions_, kMaxDimensions)
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<< "num_dimensions must be <= " << kMaxDimensions << ". Will be set to "
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<< kMaxDimensions << ".";
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num_dimensions_ = std::clamp(num_dimensions_, 1, kMaxDimensions);
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}
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std::vector<double> HaltonSequence::GetNext() {
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std::vector<double> point = {};
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point.reserve(num_dimensions_);
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for (int i = 0; i < num_dimensions_; ++i) {
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point.push_back(GetVanDerCorputSequenceElement(current_idx_, kBases[i]));
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}
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++current_idx_;
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return point;
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}
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void HaltonSequence::Reset() {
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HaltonSequence::current_idx_ = 0;
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}
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} // namespace webrtc

‎video/corruption_detection/halton_sequence.h

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/*
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* Copyright 2024 The WebRTC project authors. All rights reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef VIDEO_CORRUPTION_DETECTION_HALTON_SEQUENCE_H_
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#define VIDEO_CORRUPTION_DETECTION_HALTON_SEQUENCE_H_
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#include <vector>
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namespace webrtc {
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// Generates the Halton sequence: a low discrepancy sequence of doubles in the
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// half-open interval [0,1). See https://en.wikipedia.org/wiki/Halton_sequence
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// for information on how the sequence is constructed.
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class HaltonSequence {
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public:
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// Creates a sequence in `num_dimensions` number of dimensions. Possible
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// values are [1, 5].
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explicit HaltonSequence(int num_dimensions);
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// Creates a default sequence in a single dimension.
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HaltonSequence() = default;
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HaltonSequence(const HaltonSequence&) = default;
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HaltonSequence(HaltonSequence&&) = default;
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HaltonSequence& operator=(const HaltonSequence&) = default;
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HaltonSequence& operator=(HaltonSequence&&) = default;
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~HaltonSequence() = default;
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// Gets the next point in the sequence where each value is in the half-open
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// interval [0,1).
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std::vector<double> GetNext();
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int GetCurrentIndex() const { return current_idx_; }
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void SetCurrentIndex(int idx) { current_idx_ = idx; }
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void Reset();
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private:
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int num_dimensions_ = 1;
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int current_idx_ = 0;
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};
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} // namespace webrtc
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#endif // VIDEO_CORRUPTION_DETECTION_HALTON_SEQUENCE_H_

‎video/corruption_detection/halton_sequence_unittest.cc

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/*
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* Copyright 2024 The WebRTC project authors. All rights reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "video/corruption_detection/halton_sequence.h"
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#include "test/gmock.h"
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#include "test/gtest.h"
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namespace webrtc {
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namespace {
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using ::testing::DoubleEq;
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using ::testing::ElementsAre;
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TEST(HaltonSequenceTest, ShouldGenerateBase2SequenceByDefault) {
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HaltonSequence halton_sequence;
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EXPECT_THAT(halton_sequence.GetNext(), ElementsAre(DoubleEq(0.0)));
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EXPECT_THAT(halton_sequence.GetNext(), ElementsAre(DoubleEq(1.0 / 2)));
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EXPECT_THAT(halton_sequence.GetNext(), ElementsAre(DoubleEq(1.0 / 4)));
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EXPECT_THAT(halton_sequence.GetNext(), ElementsAre(DoubleEq(3.0 / 4)));
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EXPECT_THAT(halton_sequence.GetNext(), ElementsAre(DoubleEq(1.0 / 8)));
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EXPECT_THAT(halton_sequence.GetNext(), ElementsAre(DoubleEq(5.0 / 8)));
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EXPECT_THAT(halton_sequence.GetNext(), ElementsAre(DoubleEq(3.0 / 8)));
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}
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TEST(HaltonSequenceTest,
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ShouldGenerateBase2Base3SequencesWhenCreatedAs2Dimensional) {
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HaltonSequence halton_sequence(2);
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EXPECT_THAT(halton_sequence.GetNext(),
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ElementsAre(DoubleEq(0.0), DoubleEq(0.0)));
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EXPECT_THAT(halton_sequence.GetNext(),
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ElementsAre(DoubleEq(1.0 / 2), DoubleEq(1.0 / 3)));
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EXPECT_THAT(halton_sequence.GetNext(),
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ElementsAre(DoubleEq(1.0 / 4), DoubleEq(2.0 / 3)));
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EXPECT_THAT(halton_sequence.GetNext(),
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ElementsAre(DoubleEq(3.0 / 4), DoubleEq(1.0 / 9)));
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EXPECT_THAT(halton_sequence.GetNext(),
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ElementsAre(DoubleEq(1.0 / 8), DoubleEq(4.0 / 9)));
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EXPECT_THAT(halton_sequence.GetNext(),
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ElementsAre(DoubleEq(5.0 / 8), DoubleEq(7.0 / 9)));
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EXPECT_THAT(halton_sequence.GetNext(),
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ElementsAre(DoubleEq(3.0 / 8), DoubleEq(2.0 / 9)));
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}
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TEST(HaltonSequenceTest, ShouldRestartSequenceWhenResetIsCalled) {
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HaltonSequence halton_sequence;
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EXPECT_THAT(halton_sequence.GetCurrentIndex(), 0);
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EXPECT_THAT(halton_sequence.GetNext(), ElementsAre(DoubleEq(0.0)));
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EXPECT_THAT(halton_sequence.GetCurrentIndex(), 1);
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EXPECT_THAT(halton_sequence.GetNext(), ElementsAre(DoubleEq(1.0 / 2)));
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EXPECT_THAT(halton_sequence.GetCurrentIndex(), 2);
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halton_sequence.Reset();
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EXPECT_THAT(halton_sequence.GetCurrentIndex(), 0);
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EXPECT_THAT(halton_sequence.GetNext(), ElementsAre(DoubleEq(0.0)));
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}
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TEST(HaltonSequenceTest, ShouldSetCurrentIndexWhenSetCurrentIndexIsCalled) {
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HaltonSequence halton_sequence;
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EXPECT_THAT(halton_sequence.GetCurrentIndex(), 0);
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halton_sequence.SetCurrentIndex(3);
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EXPECT_THAT(halton_sequence.GetCurrentIndex(), 3);
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EXPECT_THAT(halton_sequence.GetNext(), ElementsAre(DoubleEq(3.0 / 4)));
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}
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} // namespace
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} // namespace webrtc

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