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/*
Copyright 2018 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS-IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
#include "dsp/reflections_processor.h"
#include <algorithm>
#include <utility>
#include <vector>
#include "third_party/googletest/googletest/include/gtest/gtest.h"
#include "api/resonance_audio_api.h"
#include "base/constants_and_types.h"
#include "utils/test_util.h"
namespace vraudio {
namespace {
const size_t kFramesPerBuffer = 512;
const int kSampleRate = 48000;
const float kRoomDimensions[3] = {2.0f, 2.0f, 2.0f};
const size_t kExpectedDelaySamples = 279;
} // namespace
class ReflectionsProcessorTest : public ::testing::Test {
protected:
void SetUp() override {
const float kReflectionCoefficients[kNumRoomSurfaces] = {0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f};
const WorldPosition kListenerPosition(0.0f, 0.0f, 0.0f);
std::copy(std::begin(kReflectionCoefficients),
std::end(kReflectionCoefficients),
std::begin(reflection_properties_.coefficients));
std::copy(std::begin(kRoomDimensions), std::end(kRoomDimensions),
std::begin(reflection_properties_.room_dimensions));
listener_position_ = kListenerPosition;
}
ReflectionProperties reflection_properties_;
WorldPosition listener_position_;
}; // namespace vraudio
// Tests that the processed output is delayed, filtered, and scaled as expected.
TEST_F(ReflectionsProcessorTest, ProcessTest) {
ReflectionsProcessor reflections_processor(kSampleRate, kFramesPerBuffer);
reflections_processor.Update(reflection_properties_, listener_position_);
AudioBuffer input(kNumMonoChannels, kFramesPerBuffer);
AudioBuffer output(kNumFirstOrderAmbisonicChannels, kFramesPerBuffer);
// Process until we have transitioned to the specified Gain.
for (size_t i = 0; i < kUnitRampLength; i += kFramesPerBuffer) {
input.Clear();
output.Clear();
GenerateDiracImpulseFilter(0, &input[0]);
reflections_processor.Process(input, &output);
}
// The reflections calculated should be as follows:
// delay = 280 samples, magnitude = 0.25, direction = {azim 90, elev 0}.
// delay = 280 samples, magnitude = 0.25, direction = {azim -90, elev 0}.
// delay = 280 samples, magnitude = 0.25, direction = {azim 0, elev -90}.
// delay = 280 samples, magnitude = 0.25, direction = {azim 0, elev 90}.
// delay = 280 samples, magnitude = 0.25, direction = {azim 0, elev 0}.
// delay = 280 samples, magnitude = 0.25, direction = {azim 180, elev 0}.
const float kExpectedMagnitude = 0.25f;
// We expect the following ambisonic encoding coefficients:
// {azim 90, elev 0} = {1 1 0 0}.
// {azim -90, elev 0} = {1 -1 0 0}.
// {azim 0, elev -90} = {1 0 -1 0}.
// {azim 0, elev 90} = {1 0 1 0}.
// {azim 0, elev 0} = {1 0 0 1}.
// {azim 180, elev 0} = {1 0 0 -1}.
const std::vector<std::vector<float>> kEncodingCoefficients = {
{1.0f, 1.0f, 0.0f, 0.0f}, {1.0f, -1.0f, 0.0f, 0.0f},
{1.0f, 0.0f, -1.0f, 0.0f}, {1.0f, 0.0f, 1.0f, 0.0f},
{1.0f, 0.0f, 0.0f, 1.0f}, {1.0f, 0.0f, 0.0f, -1.0f}};
for (size_t j = kExpectedDelaySamples; j < kFramesPerBuffer; ++j) {
for (size_t k = 0; k < kNumFirstOrderAmbisonicChannels; ++k) {
float coefficient_sum = 0.0f;
for (size_t i = 0; i < kEncodingCoefficients.size(); ++i) {
coefficient_sum += kEncodingCoefficients[i][k];
}
const float expected_sample = input[0][j - kExpectedDelaySamples] *
kExpectedMagnitude * coefficient_sum;
EXPECT_NEAR(expected_sample, output[k][j], kEpsilonFloat);
}
}
}
// Tests that when transitioning from a reflection with zero magnitude to one
// with non-zero magnitude, there will be a steady incremental increase in
// the "fade in".
TEST_F(ReflectionsProcessorTest, CrossFadeTest) {
ReflectionsProcessor reflections_processor(kSampleRate, kFramesPerBuffer);
AudioBuffer input(kNumMonoChannels, kFramesPerBuffer);
AudioBuffer output(kNumFirstOrderAmbisonicChannels, kFramesPerBuffer);
input.Clear();
output.Clear();
for (size_t i = 0; i < kFramesPerBuffer; ++i) {
input[0][i] = 1.0f;
}
reflections_processor.Process(input, &output);
reflections_processor.Update(reflection_properties_, listener_position_);
reflections_processor.Process(input, &output);
// All the reflections are expected to arrive at the listener at the same
// time. That is why their directional contributions are expected to cancel
// out. Only in first channel we will see a steady increase.
for (size_t channel = 0; channel < kNumFirstOrderAmbisonicChannels;
++channel) {
if (channel < kNumMonoChannels) {
for (size_t frame = kExpectedDelaySamples; frame < kFramesPerBuffer;
++frame) {
EXPECT_TRUE(output[channel][frame] > output[channel][frame - 1]);
}
} else {
for (size_t frame = 0; frame < kFramesPerBuffer; ++frame) {
EXPECT_NEAR(output[channel][frame], 0.0f, kEpsilonFloat);
}
}
}
}
} // namespace vraudio
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