private void WhisperFilter(Wave wave)
{
Func <int, int, double> windowFunction = Hamming;
int length = wave.Data.Length;
double[] x = new double[frame];
double[] y = new double[frame];
double[] E = new double[frame]; //残差信号
double[] a = new double[Order + 1]; //LPC係数
double[] v = wave.Data;
double[] v1 = new double[v.Length];
double[] v2 = new double[v.Length];
for (int i = 0; i < length / frame * 2 - 1; i++)
{
double max = 0.0;
for (int j = 0; j < frame; j++)
{
x[j] = v[j + i * frame / 2] * windowFunction(j, frame);
}
//LPC係数の導出
LevinsonDurbin(x, frame, a, Order);
//残差信号(声帯音源)の導出
for (int j = 0; j < frame; j++)
{
double e = 0.0;
for (int n = 0; n < Order + 1; n++)
{
if (j >= n)
{
e += a[n] * x[j - n];
}
}
E[j] = e;
max += e * e;
}
//声帯振動
for (int j = 0; j < frame; j++)
{
v2[j + i * frame / 2] += E[j] * 10.0;
}
//ホワイトノイズの生成
for (int j = 0; j < frame; j++)
{
y[j] = GenerateWhiteNoise();
}
for (int j = 1; j < frame; j++)
{
E[j] = ((1.0 - Rate) * E[j - 1] + E[j]) / (2.0 - Rate);
}
//残差信号とノイズの二乗平均レベルをそろえる
max = Math.Sqrt(3.0 * max / frame);
for (int j = 0; j < frame; j++)
{
y[j] = Rate * E[j] + (1.0 - Rate) * max * y[j];
}
//for (int j=1; j<order+1; j++) a[j] *= pow(alpha, (double)j);
//音声合成フィルタ
for (int j = 0; j < frame; j++)
{
for (int n = 1; n < Order + 1; n++)
{
if (j >= n)
{
y[j] -= a[n] * y[j - n];
}
}
}
for (int j = 0; j < frame; j++)
{
v1[j + i * frame / 2] += y[j];
}
}
//デエンファシス
for (int i = 1; i < length; i++)
{
v1[i] = Lpf * v1[i - 1] + v1[i];
}
for (int i = 1; i < length; i++)
{
v2[i] = 0.97 * v2[i - 1] + v2[i];
}
wave.Data = v1;
wave.EData = v2;
}
public void Convert(Wave wave)
{
AdjustSize(wave);
WhisperFilter(wave);
}