public void testStretch1() {
double[] signal = FFTTest.getSampleSignal(2048 + 128);
int samplingRate = 8000;
double rateFactor = 0.5;
NaiveVocoder nv =
new NaiveVocoder(new BufferedDoubleDataSource(signal), samplingRate, rateFactor);
double[] result = nv.getAllData();
int expectedLength = nv.computeOutputLength(signal.length);
assertTrue(
"Expected result length: " + expectedLength + ", found: " + result.length,
result.length == expectedLength);
}
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);
}
