float[,] LoadSong(string path)
{
IWaveSource reader = new MediaFoundationDecoder(path);
var sampleRate = reader.WaveFormat.SampleRate;
reader = reader.ToMono();
MemoryStream cache = new MemoryStream();
reader.WriteToWaveStream(cache);
cache.Position = 0;
reader.Dispose();
reader = new WaveFileReader(cache);
var r = reader.ToSampleSource();
// Samples per key
var fftSamplesPerKey = 10;
// Width of the array
var fftWidth = 10000;
// Number of subdivisions in each sample group
// Higher = more precise
var precisionMultiplier = 5;
// Wavelengths in each sample
// Higher = more precise
var wavelengthsPerSample = 20;
var fftResultLen = 128 * fftSamplesPerKey;
int len = (int)(reader.Length / 2);
var result = new float[fftWidth, fftResultLen];
var datafull = new float[(int)len];
r.Read(datafull, 0, (int)len);
r.Dispose();
int progress = 0;
object lck = new object();
Stopwatch s = new Stopwatch();
s.Start();
Parallel.For(0, fftResultLen, i =>
{
float key = i / (float)fftSamplesPerKey - 0.5f / fftSamplesPerKey;
float freq = (float)Math.Pow(2, (key - 69 + 9 - 7 * 3 + 12 * 1) / 12) * 440;
int waveSize = (int)(sampleRate / freq) * wavelengthsPerSample;
double waveStep = (double)waveSize * fftWidth / len;
waveStep /= precisionMultiplier;
if (waveStep < 1)
{
waveStep = 1;
}
waveStep = waveStep / fftWidth * len;
if (waveSize < 1000)
{
waveSize = 1000;
}
for (double _l = 0; _l + waveSize < len; _l += waveStep)
{
var l = (int)_l;
float mult = freq / sampleRate * (float)Math.PI * 2;
float sum_r = 0;
float sum_i = 0;
for (int j = 0; j < waveSize; j++)
{
float a = mult * j + (float)Math.PI;
sum_r += (float)Math.Cos(a) * datafull[l + j];
sum_i += (float)Math.Sin(a) * datafull[l + j];
}
var val = (Math.Abs(sum_r) + Math.Abs(sum_i)) / waveSize;
int start = (int)((double)l * fftWidth / len);
int end = (int)((double)(l + waveSize) * fftWidth / len);
for (int p = start; p <= end; p++)
{
result[p, i] = val;
}
}
lock (lck)
{
Console.WriteLine("Processed frequency bands: " + (++progress));
}
});
Console.WriteLine("Complete! Seconds spent: " + Math.Round(s.ElapsedMilliseconds / 1000.0, 1));
return(result);
}
float[,] LoadSong(string path)
{
IWaveSource reader = new MediaFoundationDecoder(path);
var sampleRate = reader.WaveFormat.SampleRate;
reader = reader.ToMono();
MemoryStream cache = new MemoryStream();
reader.WriteToWaveStream(cache);
cache.Position = 0;
reader.Dispose();
reader = new WaveFileReader(cache);
var r = reader.ToSampleSource();
// Samples per key
var fftSamplesPerKey = 10;
// Width of the array
var fftWidth = 10000;
// Number of subdivisions in each sample group
// Higher = more precise
var precisionMultiplier = 5;
// Wavelengths in each sample
// Higher = more precise
var wavelengthsPerSample = 20;
var fftResultLen = 128 * fftSamplesPerKey;
int len = (int)(reader.Length / 2);
var result = new float[fftWidth, fftResultLen];
var datafull = new float[(int)len];
r.Read(datafull, 0, (int)len);
r.Dispose();
int progress = 0;
object lck = new object();
Stopwatch s = new Stopwatch();
s.Start();
unsafe
{
fixed(float *input_ptr = datafull)
{
float *output_ptr = (float *)CudaFFT.process_audio((IntPtr)input_ptr, (ulong)len, (uint)sampleRate);
ulong idx = 0;
for (int x = 0; x < fftWidth; x++)
{
for (int y = 0; y < fftResultLen; y++)
{
result[x, y] = output_ptr[idx++];
}
}
}
}
Console.WriteLine("Complete! Seconds spent: " + Math.Round(s.ElapsedMilliseconds / 1000.0, 1));
return(result);
}
