blob: f5b436f1b9c00aef21132163999f9ba47bac902a [file] [log] [blame]
/*
* Copyright 2014 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 "rtc_base/numerics/exp_filter.h"
#include <cmath>
#include "test/gtest.h"
namespace rtc {
TEST(ExpFilterTest, FirstTimeOutputEqualInput) {
// No max value defined.
ExpFilter filter = ExpFilter(0.9f);
filter.Apply(100.0f, 10.0f);
// First time, first argument no effect.
double value = 10.0f;
EXPECT_FLOAT_EQ(value, filter.filtered());
}
TEST(ExpFilterTest, SecondTime) {
float value;
ExpFilter filter = ExpFilter(0.9f);
filter.Apply(100.0f, 10.0f);
// First time, first argument no effect.
value = 10.0f;
filter.Apply(10.0f, 20.0f);
float alpha = std::pow(0.9f, 10.0f);
value = alpha * value + (1.0f - alpha) * 20.0f;
EXPECT_FLOAT_EQ(value, filter.filtered());
}
TEST(ExpFilterTest, Reset) {
ExpFilter filter = ExpFilter(0.9f);
filter.Apply(100.0f, 10.0f);
filter.Reset(0.8f);
filter.Apply(100.0f, 1.0f);
// Become first time after a reset.
double value = 1.0f;
EXPECT_FLOAT_EQ(value, filter.filtered());
}
TEST(ExpfilterTest, OutputLimitedByMax) {
double value;
// Max value defined.
ExpFilter filter = ExpFilter(0.9f, 1.0f);
filter.Apply(100.0f, 10.0f);
// Limited to max value.
value = 1.0f;
EXPECT_EQ(value, filter.filtered());
filter.Apply(1.0f, 0.0f);
value = 0.9f * value;
EXPECT_FLOAT_EQ(value, filter.filtered());
}
} // namespace rtc