TEST (AudioDataTest, DownsamplerInsistsOnMonophonicAudio) {
KeyFinder::AudioData a;
a.setChannels(2);
a.setFrameRate(100);
a.addToSampleCount(10);
ASSERT_THROW(a.downsample(5), KeyFinder::Exception);
a.reduceToMono();
ASSERT_NO_THROW(a.downsample(5));
}
TEST (AudioDataTest, DownsamplerResamplesIntegralRelationship) {
KeyFinder::AudioData a;
a.setChannels(1);
a.setFrameRate(100);
a.addToSampleCount(10);
for (unsigned int i = 0; i < 5; i++)
a.setSample(i, 100.0);
for (unsigned int i = 5; i < 10; i++)
a.setSample(i, 500.0);
a.downsample(5);
ASSERT_EQ(20, a.getFrameRate());
ASSERT_EQ(2, a.getSampleCount());
ASSERT_FLOAT_EQ(100.0, a.getSample(0));
ASSERT_FLOAT_EQ(500.0, a.getSample(1));
}
TEST (AudioDataTest, DownsamplerResamplesNonintegralRelationship) {
KeyFinder::AudioData a;
a.setChannels(1);
a.setFrameRate(100);
a.addToSampleCount(12);
for (unsigned int i = 0; i < 5; i++)
a.setSample(i, 100.0);
for (unsigned int i = 5; i < 10; i++)
a.setSample(i, 500.0);
for (unsigned int i = 10; i < 12; i++)
a.setSample(i, 1000.0);
a.downsample(5);
ASSERT_EQ(3, a.getSampleCount());
ASSERT_FLOAT_EQ(100.0, a.getSample(0));
ASSERT_FLOAT_EQ(500.0, a.getSample(1));
// this doesn't make total mathematical sense but I'm taking a shortcut for performance
ASSERT_FLOAT_EQ(1000.0, a.getSample(2));
}
TEST (AudioDataTest, DownsamplerResamplesSineWave) {
unsigned int frameRate = 10000;
unsigned int frames = frameRate * 4;
float freq = 20;
float magnitude = 32768.0;
unsigned int factor = 5;
KeyFinder::AudioData a;
a.setChannels(1);
a.setFrameRate(frameRate);
a.addToSampleCount(frames);
for (unsigned int i = 0; i < frames; i++)
a.setSample(i, sine_wave(i, freq, frameRate, magnitude));
a.downsample(factor);
unsigned int newFrameRate = frameRate / factor;
unsigned int newFrames = frames / factor;
ASSERT_EQ(newFrameRate, a.getFrameRate());
ASSERT_EQ(newFrames, a.getSampleCount());
for (unsigned int i = 0; i < newFrames; i++)
ASSERT_NEAR(sine_wave(i, freq, newFrameRate, magnitude), a.getSample(i), magnitude * 0.05);
}