TEST_F(WaveformGeneratorTest, shouldComputeMaxAndMinValuesFromStereoInput)
{
WaveformBuffer buffer;
const int samples_per_pixel = 300;
SamplesPerPixelScaleFactor scale_factor(samples_per_pixel);
WaveformGenerator generator(buffer, scale_factor);
const int sample_rate = 44100;
const int channels = 2;
const int BUFFER_SIZE = 1024;
short samples[BUFFER_SIZE];
memset(samples, 0, sizeof(samples));
const int frames = BUFFER_SIZE / channels;
bool result = generator.init(sample_rate, channels, BUFFER_SIZE);
ASSERT_TRUE(result);
ASSERT_TRUE(error.str().empty());
// even indexes: left channel, odd indexes: right channel
samples[0] = 100;
samples[1] = 102;
samples[200] = 98;
samples[201] = 100;
samples[400] = -98;
samples[401] = -100;
samples[598] = -100;
samples[599] = -102;
samples[600] = 197;
samples[601] = 199;
samples[800] = -200;
samples[801] = -202;
samples[900] = -197;
samples[901] = -199;
samples[1022] = 200;
samples[1023] = 202;
result = generator.process(samples, frames);
ASSERT_TRUE(result);
generator.done();
// Check contents of buffer
ASSERT_THAT(buffer.getSampleRate(), Eq(44100));
ASSERT_THAT(buffer.getSamplesPerPixel(), Eq(300));
ASSERT_THAT(buffer.getSize(), Eq(2)); // 512 / 300 = 1 remainder 212
// => 2 output points total
// Check min and max values are average of left and right channels
ASSERT_THAT(buffer.getMinSample(0), Eq(-101));
ASSERT_THAT(buffer.getMaxSample(0), Eq(101));
ASSERT_THAT(buffer.getMinSample(1), Eq(-201));
ASSERT_THAT(buffer.getMaxSample(1), Eq(201));
}
TEST_F(WaveformGeneratorTest, shouldComputeMaxAndMinValuesFromMonoInput)
{
WaveformBuffer buffer;
const int samples_per_pixel = 300;
SamplesPerPixelScaleFactor scale_factor(samples_per_pixel);
WaveformGenerator generator(buffer, scale_factor);
const int sample_rate = 44100;
const int channels = 1;
const int BUFFER_SIZE = 512;
short samples[BUFFER_SIZE];
memset(samples, 0, sizeof(samples));
const int frames = BUFFER_SIZE / channels;
bool result = generator.init(sample_rate, channels, BUFFER_SIZE);
ASSERT_TRUE(result);
ASSERT_TRUE(error.str().empty());
// samples for first waveform data point
samples[0] = 100;
samples[100] = 98;
samples[200] = -98;
samples[299] = -102;
// samples for second waveform data point
samples[300] = 197;
samples[400] = -200;
samples[450] = -197;
samples[511] = 202;
result = generator.process(samples, frames);
ASSERT_TRUE(result);
generator.done();
// Check contents of buffer
ASSERT_THAT(buffer.getSampleRate(), Eq(44100));
ASSERT_THAT(buffer.getSamplesPerPixel(), Eq(300));
ASSERT_THAT(buffer.getSize(), Eq(2)); // 512 / 300 = 1 remainder 212
// => 2 output points total
// Check min and max values
ASSERT_THAT(buffer.getMinSample(0), Eq(-102));
ASSERT_THAT(buffer.getMaxSample(0), Eq(100));
ASSERT_THAT(buffer.getMinSample(1), Eq(-200));
ASSERT_THAT(buffer.getMaxSample(1), Eq(202));
}
TEST_F(WaveformGeneratorTest, shouldSetBufferAttributes)
{
WaveformBuffer buffer;
const int samples_per_pixel = 300;
WaveformGenerator generator(buffer, samples_per_pixel);
const int sample_rate = 44100;
const int channels = 2;
const int BUFFER_SIZE = 1024;
bool result = generator.init(sample_rate, channels, BUFFER_SIZE);
ASSERT_TRUE(result);
ASSERT_THAT(buffer.getSampleRate(), Eq(44100));
ASSERT_THAT(buffer.getSamplesPerPixel(), Eq(300));
}
TEST_F(WaveformGeneratorTest, shouldSucceedIfEndTimeGreaterThanStartTime)
{
WaveformBuffer buffer;
DurationScaleFactor scale_factor(2.0, 3.0, 100);
WaveformGenerator generator(buffer, scale_factor);
const int sample_rate = 44100;
const int channels = 2;
const int BUFFER_SIZE = 1024;
bool result = generator.init(sample_rate, channels, BUFFER_SIZE);
ASSERT_TRUE(result);
ASSERT_TRUE(error.str().empty());
ASSERT_THAT(generator.getSamplesPerPixel(), Eq(441));
ASSERT_THAT(buffer.getSampleRate(), Eq(44100));
ASSERT_THAT(buffer.getSamplesPerPixel(), Eq(441));
}
bool GdImageRenderer::create(
const WaveformBuffer& buffer,
const double start_time,
const int image_width,
const int image_height,
const WaveformColors& colors,
const bool render_axis_labels)
{
if (start_time < 0.0) {
error_stream << "Invalid start time: minimum 0\n";
return false;
}
else if (start_time > MAX_START_TIME) {
error_stream << "Invalid start time: maximum " << MAX_START_TIME << '\n';
return false;
}
if (image_width < 1) {
error_stream << "Invalid image width: minimum 1\n";
return false;
}
if (image_height < 1) {
error_stream << "Invalid image height: minimum 1\n";
return false;
}
const int sample_rate = buffer.getSampleRate();
if (sample_rate > MAX_SAMPLE_RATE) {
error_stream << "Invalid sample rate: " << sample_rate
<< " Hz, maximum " << MAX_SAMPLE_RATE << " Hz\n";
return false;
}
const int samples_per_pixel = buffer.getSamplesPerPixel();
if (samples_per_pixel > MAX_ZOOM) {
error_stream << "Invalid zoom: maximum " << MAX_ZOOM << '\n';
return false;
}
image_ = gdImageCreateTrueColor(image_width, image_height);
if (image_ == nullptr) {
error_stream << "Failed to create image\n";
return false;
}
assert(sample_rate != 0);
assert(samples_per_pixel != 0);
image_width_ = image_width;
image_height_ = image_height;
start_time_ = start_time;
sample_rate_ = buffer.getSampleRate();
samples_per_pixel_ = samples_per_pixel;
start_index_ = secondsToPixels(start_time);
render_axis_labels_ = render_axis_labels;
output_stream << "Image dimensions: " << image_width_ << "x" << image_height_ << " pixels"
<< "\nSample rate: " << sample_rate_ << " Hz"
<< "\nSamples per pixel: " << samples_per_pixel_
<< "\nStart time: " << start_time_ << " seconds"
<< "\nStart index: " << start_index_
<< "\nBuffer size: " << buffer.getSize()
<< "\nAxis labels: " << (render_axis_labels_ ? "yes" : "no") << std::endl;
if (colors.hasAlpha()) {
gdImageSaveAlpha(image_, 1);
gdImageAlphaBlending(image_, 0);
}
initColors(colors);
drawBackground();
if (render_axis_labels_) {
drawBorder();
}
drawWaveform(buffer);
if (render_axis_labels_) {
drawTimeAxisLabels();
}
return true;
}
