public void testStretch2() {
double[] signal = FFTTest.getSampleSignal(16000);
int samplingRate = 8000;
double rateFactor = 0.5;
NaiveVocoder nv =
new NaiveVocoder(new BufferedDoubleDataSource(signal), samplingRate, rateFactor);
double[] result = nv.getAllData();
double meanSignalEnergy = MathUtils.mean(MathUtils.multiply(signal, signal));
double meanResultEnergy = MathUtils.mean(MathUtils.multiply(result, result));
double percentDifference =
Math.abs(meanSignalEnergy - meanResultEnergy) / meanSignalEnergy * 100;
assertTrue(
"Stretching changed signal energy by " + percentDifference + "%", percentDifference < 6);
}
// st: Sinusoidal tracks
// absMaxDesired: Desired absolute maximum of the output
public double[] synthesize(SinusoidalTracks st, boolean isSilentSynthesis) {
int n; // discrete time index
int i, j;
int nStart, nEnd, pStart, pEnd;
float t; // continuous time
float t2; // continuous time squared
float t3; // continuous time cubed
float tFinal = st.getOriginalDuration();
int nFinal = (int) (Math.floor(tFinal * st.fs + 0.5));
double[] y = new double[nFinal + 1];
Arrays.fill(y, 0.0);
float currentAmp;
float currentTheta;
double alpha, beta;
int M;
float
T; // Number of samples between consecutive frames (equals to pitch period in pitch
// synchronous analysis/synthesis)
float T2; // T squared
float T3; // T cubed
double oneOverTwoPi = 1.0 / MathUtils.TWOPI;
double term1, term2;
float currentTime; // For debugging purposes
for (i = 0; i < st.totalTracks; i++) {
for (j = 0; j < st.tracks[i].totalSins - 1; j++) {
if (st.tracks[i].states[j] != SinusoidalTrack.TURNED_OFF) {
pStart = (int) Math.floor(st.tracks[i].times[j] * st.fs + 0.5);
pEnd = (int) Math.floor(st.tracks[i].times[j + 1] * st.fs + 0.5);
nStart = Math.max(0, pStart);
nEnd = Math.max(0, pEnd);
nStart = Math.min(y.length - 1, nStart);
nEnd = Math.min(y.length - 1, nEnd);
// currentTime = 0.5f*(nEnd+nStart)/st.fs;
// System.out.println("currentTime=" + String.valueOf(currentTime));
for (n = nStart; n < nEnd; n++) {
if (false) // Direct synthesis
{
currentAmp = st.tracks[i].amps[j];
currentTheta = (n - nStart) * st.tracks[i].freqs[j] + st.tracks[i].phases[j];
y[n] += currentAmp * Math.cos(currentTheta);
} else // Synthesis with interpolation
{
// Amplitude interpolation
currentAmp =
st.tracks[i].amps[j]
+ (st.tracks[i].amps[j + 1] - st.tracks[i].amps[j])
* ((float) n - pStart)
/ (pEnd - pStart + 1);
T = (pEnd - pStart);
if (n == nStart
&& st.tracks[i].states[j] == SinusoidalTrack.TURNED_ON) // Turning on a track
{
// Quatieri
currentTheta = st.tracks[i].phases[j + 1] - T * st.tracks[i].freqs[j + 1];
currentAmp = 0.0f;
} else if (n == nStart
&& st.tracks[i].states[j] == SinusoidalTrack.TURNED_OFF
&& j > 0) // Turning off a track
{
// Quatieri
currentTheta = st.tracks[i].phases[j - 1] + T * st.tracks[i].freqs[j - 1];
currentAmp = 0.0f;
} else // Cubic phase interpolation
{
// Quatieri
M =
(int)
(Math.floor(
oneOverTwoPi
* ((st.tracks[i].phases[j]
+ T * st.tracks[i].freqs[j]
- st.tracks[i].phases[j + 1])
+ (st.tracks[i].freqs[j + 1] - st.tracks[i].freqs[j])
* 0.5
* T)
+ 0.5));
term1 =
st.tracks[i].phases[j + 1]
- st.tracks[i].phases[j]
- T * st.tracks[i].freqs[j]
+ M * MathUtils.TWOPI;
term2 = st.tracks[i].freqs[j + 1] - st.tracks[i].freqs[j];
T2 = T * T;
T3 = T * T2;
alpha = 3.0 * term1 / T2 - term2 / T;
beta = -2 * term1 / T3 + term2 / T2;
t = ((float) n - nStart);
t2 = t * t;
t3 = t * t2;
// Quatieri
currentTheta =
(float)
(st.tracks[i].phases[j]
+ st.tracks[i].freqs[j] * t
+ alpha * t2
+ beta * t3);
}
// Synthesis
y[n] += currentAmp * Math.cos(currentTheta);
}
// System.out.println(String.valueOf(currentTheta));
}
}
}
if (!isSilentSynthesis)
System.out.println(
"Synthesized track " + String.valueOf(i + 1) + " of " + String.valueOf(st.totalTracks));
}
y = MathUtils.multiply(y, st.absMaxOriginal / MathUtils.getAbsMax(y));
return y;
}