/// <summary>
/// xxxxxxxx
/// xxxxxxxx
/// xxxxxxxx
/// xxxxxxxx
/// </summary>
private double Filter0(IntegralImage i, int x, int y, int w, int h)
{
double a = i.CalculateArea(x, y, x + w - 1, y + h - 1);
double b = 0;
return(Subtract(a, b));
}
/// <summary>
/// ........
/// ........
/// xxxxxxxx
/// xxxxxxxx
/// </summary>
private double Filter1(IntegralImage i, int x, int y, int w, int h)
{
int halfH = h / 2;
double a = i.CalculateArea(x, y + halfH, x + w - 1, y + h - 1);
double b = i.CalculateArea(x, y, x + w - 1, y + halfH - 1);
return(Subtract(a, b));
}
/// <summary>
/// ...xxx...
/// ...xxx...
/// ...xxx...
/// <summary>
private double Filter5(IntegralImage i, int x, int y, int w, int h)
{
int thirdW = w / 3;
double a = i.CalculateArea(x + thirdW, y, x + 2 * thirdW - 1, y + h - 1);
double b = i.CalculateArea(x, y, x + thirdW - 1, y + h - 1) +
i.CalculateArea(x + 2 * thirdW, y, x + w - 1, y + h - 1);
return(Subtract(a, b));
}
public int Classify(IntegralImage image, int offset)
{
var filterValue = filter.Apply(image, offset);
return(quantizer.Quantize(filterValue));
}
public void Generate(AudioTrack track)
{
IAudioStream audioStream = new ResamplingStream(
new MonoStream(AudioStreamFactory.FromFileInfoIeee32(track.FileInfo)),
ResamplingQuality.Medium, profile.SamplingRate);
var chroma = new Chroma(audioStream, profile.WindowSize, profile.HopSize, profile.WindowType,
profile.ChromaMinFrequency, profile.ChromaMaxFrequency, false, profile.ChromaMappingMode);
float[] chromaFrame;
var chromaBuffer = new RingBuffer <float[]>(profile.ChromaFilterCoefficients.Length);
var chromaFilterCoefficients = profile.ChromaFilterCoefficients;
var filteredChromaFrame = new double[Chroma.Bins];
var classifiers = profile.Classifiers;
var maxFilterWidth = classifiers.Max(c => c.Filter.Width);
var integralImage = new IntegralImage(maxFilterWidth, Chroma.Bins);
int index = 0;
int indices = chroma.WindowCount;
var subFingerprints = new List <SubFingerprint>();
while (chroma.HasNext())
{
// Get chroma frame buffer
// When the chroma buffer is full, we can take and reuse the oldest array
chromaFrame = chromaBuffer.Count == chromaBuffer.Length ? chromaBuffer[0] : new float[Chroma.Bins];
// Read chroma frame into buffer
chroma.ReadFrame(chromaFrame);
// ChromaFilter
chromaBuffer.Add(chromaFrame);
if (chromaBuffer.Count < chromaBuffer.Length)
{
// Wait for the buffer to fill completely for the filtering to start
continue;
}
Array.Clear(filteredChromaFrame, 0, filteredChromaFrame.Length);
for (int i = 0; i < chromaFilterCoefficients.Length; i++)
{
var frame = chromaBuffer[i];
for (int j = 0; j < frame.Length; j++)
{
filteredChromaFrame[j] += frame[j] * chromaFilterCoefficients[i];
}
}
// ChromaNormalizer
double euclideanNorm = 0;
for (int i = 0; i < filteredChromaFrame.Length; i++)
{
var value = filteredChromaFrame[i];
euclideanNorm += value * value;
}
euclideanNorm = Math.Sqrt(euclideanNorm);
if (euclideanNorm < profile.ChromaNormalizationThreshold)
{
Array.Clear(filteredChromaFrame, 0, filteredChromaFrame.Length);
}
else
{
for (int i = 0; i < filteredChromaFrame.Length; i++)
{
filteredChromaFrame[i] /= euclideanNorm;
}
}
// ImageBuilder
// ... just add one feature vector after another as rows to the image
integralImage.AddColumn(filteredChromaFrame);
// FingerprintCalculator
if (integralImage.Columns < maxFilterWidth)
{
// Wait for the image to fill completely before hashes can be generated
continue;
}
// Calculate subfingerprint hash
uint hash = 0;
for (int i = 0; i < classifiers.Length; i++)
{
hash = (hash << 2) | grayCodeMapping[classifiers[i].Classify(integralImage, 0)];
}
// We have a SubFingerprint@frameTime
subFingerprints.Add(new SubFingerprint(index, new SubFingerprintHash(hash), false));
index++;
if (index % 512 == 0 && SubFingerprintsGenerated != null)
{
SubFingerprintsGenerated(this, new SubFingerprintsGeneratedEventArgs(track, subFingerprints, index, indices));
subFingerprints.Clear();
}
}
if (SubFingerprintsGenerated != null)
{
SubFingerprintsGenerated(this, new SubFingerprintsGeneratedEventArgs(track, subFingerprints, index, indices));
}
if (Completed != null)
{
Completed(this, EventArgs.Empty);
}
audioStream.Close();
}
public double Apply(IntegralImage image, int x)
{
return(FilterFunction(image, x, y, width, height));
}
