blob: 2a28fe7d3082fd2357088c08ad00f47910579a6f [file] [log] [blame]
// Copyright (c) 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "media/base/feedback_signal_accumulator.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace media {
class FeedbackSignalAccumulatorTest : public ::testing::Test {
public:
FeedbackSignalAccumulatorTest()
: half_life_(base::TimeDelta::FromSeconds(1)),
acc_(half_life_),
t_(base::TimeTicks() + base::TimeDelta::FromSeconds(120)) {
acc_.Reset(0.0, t_);
}
protected:
const base::TimeDelta half_life_;
FeedbackSignalAccumulator<base::TimeTicks> acc_;
base::TimeTicks t_;
};
TEST_F(FeedbackSignalAccumulatorTest, HasCorrectStartingValueAfterReset) {
ASSERT_EQ(0.0, acc_.current());
ASSERT_EQ(t_, acc_.reset_time());
ASSERT_EQ(t_, acc_.update_time());
acc_.Reset(1.0, t_);
ASSERT_EQ(1.0, acc_.current());
ASSERT_EQ(t_, acc_.reset_time());
ASSERT_EQ(t_, acc_.update_time());
t_ += half_life_;
acc_.Reset(2.0, t_);
ASSERT_EQ(2.0, acc_.current());
ASSERT_EQ(t_, acc_.reset_time());
ASSERT_EQ(t_, acc_.update_time());
}
TEST_F(FeedbackSignalAccumulatorTest, DoesNotUpdateIfBeforeResetTime) {
acc_.Reset(0.0, t_);
ASSERT_EQ(0.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
const base::TimeTicks one_usec_before =
t_ - base::TimeDelta::FromMicroseconds(1);
ASSERT_FALSE(acc_.Update(1.0, one_usec_before));
ASSERT_EQ(0.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
const base::TimeTicks one_usec_after =
t_ + base::TimeDelta::FromMicroseconds(1);
ASSERT_TRUE(acc_.Update(1.0, one_usec_after));
ASSERT_LT(0.0, acc_.current());
ASSERT_EQ(one_usec_after, acc_.update_time());
}
TEST_F(FeedbackSignalAccumulatorTest, TakesMaxOfUpdatesAtResetTime) {
acc_.Reset(0.0, t_);
ASSERT_EQ(0.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(1.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
ASSERT_TRUE(acc_.Update(2.0, t_));
ASSERT_EQ(2.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(2.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
}
TEST_F(FeedbackSignalAccumulatorTest, AppliesMaxOfUpdatesWithSameTimestamp) {
acc_.Reset(0.0, t_);
ASSERT_EQ(0.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 1 * half_life_;
// Update with an identical value at the same timestamp.
for (int i = 0; i < 3; ++i) {
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(0.5, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
}
// Now continue updating with different values at the same timestamp.
ASSERT_TRUE(acc_.Update(2.0, t_));
ASSERT_EQ(1.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
ASSERT_TRUE(acc_.Update(3.0, t_));
ASSERT_EQ(1.5, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(1.5, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
}
TEST_F(FeedbackSignalAccumulatorTest, ProvidesExpectedHoldResponse) {
// Step one half-life interval per update.
acc_.Reset(0.0, t_);
ASSERT_EQ(0.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 1 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(0.5, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 1 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(0.75, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 1 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(0.875, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 1 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(0.9375, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
// Step two half-life intervals per update.
acc_.Reset(0.0, t_);
ASSERT_EQ(0.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 2 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_NEAR(0.666666667, acc_.current(), 0.000000001);
ASSERT_EQ(t_, acc_.update_time());
t_ += 2 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_NEAR(0.888888889, acc_.current(), 0.000000001);
ASSERT_EQ(t_, acc_.update_time());
t_ += 2 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_NEAR(0.962962963, acc_.current(), 0.000000001);
ASSERT_EQ(t_, acc_.update_time());
t_ += 2 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_NEAR(0.987654321, acc_.current(), 0.000000001);
ASSERT_EQ(t_, acc_.update_time());
// Step three half-life intervals per update.
acc_.Reset(0.0, t_);
ASSERT_EQ(0.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 3 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(0.75, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 3 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(0.9375, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 3 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(0.984375, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 3 * half_life_;
ASSERT_TRUE(acc_.Update(1.0, t_));
ASSERT_EQ(0.99609375, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
}
TEST_F(FeedbackSignalAccumulatorTest, IgnoresUpdatesThatAreOutOfOrder) {
// First, go forward several steps, in order.
acc_.Reset(0.0, t_);
ASSERT_EQ(0.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 1 * half_life_;
ASSERT_TRUE(acc_.Update(2.0, t_));
ASSERT_EQ(1.0, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 1 * half_life_;
ASSERT_TRUE(acc_.Update(2.0, t_));
ASSERT_EQ(1.5, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 1 * half_life_;
ASSERT_TRUE(acc_.Update(2.0, t_));
ASSERT_EQ(1.75, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
t_ += 1 * half_life_;
ASSERT_TRUE(acc_.Update(2.0, t_));
ASSERT_EQ(1.875, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
// Go back 1 steps, then 1.5, then 2, then 2.5, etc. and expect the update to
// fail each time.
base::TimeTicks earlier = t_ - 1 * half_life_;
for (int i = 0; i < 5; ++i) {
ASSERT_FALSE(acc_.Update(999.0, earlier));
ASSERT_EQ(1.875, acc_.current());
ASSERT_EQ(t_, acc_.update_time());
earlier -= half_life_ / 2;
}
}
} // namespace media