/**
* Copyright 2004-2006 DFKI GmbH.
* All Rights Reserved. Use is subject to license terms.
*
* This file is part of MARY TTS.
*
* MARY TTS is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
package marytts.signalproc.process;
import java.io.File;
import javax.sound.sampled.AudioFileFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import marytts.signalproc.analysis.LpcAnalyser;
import marytts.signalproc.analysis.LpcAnalyser.LpCoeffs;
import marytts.signalproc.filter.FIRFilter;
import marytts.signalproc.filter.RecursiveFilter;
import marytts.signalproc.window.Window;
import marytts.util.data.BufferedDoubleDataSource;
import marytts.util.data.audio.AudioDoubleDataSource;
import marytts.util.data.audio.DDSAudioInputStream;
import marytts.util.math.ArrayUtils;
/**
* A base class for LPC-based analysis and resynthesis, which does nothing.
*
* @author Marc Schröder
*
*/
public class LPCAnalysisResynthesis implements InlineDataProcessor {
protected int p;
/**
* Apply LPC analysis-resynthesis.
*
* @param p
* prediction order, i.e. number of LPC coefficients to compute.
*/
public LPCAnalysisResynthesis(int p) {
this.p = p;
}
public void applyInline(double[] data, int off, int len) {
assert off == 0;
assert len == data.length;
// Compute LPC coefficients and residual
LpCoeffs coeffs = LpcAnalyser.calcLPC(data, p);
// double gain = coeffs.getGain();
double[] residual = ArrayUtils.subarray(new FIRFilter(coeffs.getOneMinusA()).apply(data), 0, len);
// Do something fancy with the lpc coefficients and/or the residual
processLPC(coeffs, residual);
// Resynthesise audio from residual and LPC coefficients
double[] newData = new RecursiveFilter(coeffs.getA()).apply(residual);
// System.err.println("Sum squared error:"+MathUtils.sumSquaredError(data, newData));
System.arraycopy(newData, 0, data, 0, len);
}
/**
* Process the LPC coefficients and/or the residual in place. This method does nothing; subclasses may want to override it to
* do something meaningful.
*
* @param coeffs
* the LPC coefficients
* @param residual
* the residual, of length framelength
*/
protected void processLPC(LpCoeffs coeffs, double[] residual) {
}
public static void main(String[] args) throws Exception {
for (int i = 0; i < args.length; i++) {
AudioInputStream inputAudio = AudioSystem.getAudioInputStream(new File(args[i]));
int samplingRate = (int) inputAudio.getFormat().getSampleRate();
AudioDoubleDataSource signal = new AudioDoubleDataSource(inputAudio);
int frameLength = Integer.getInteger("signalproc.lpcanalysissynthesis.framelength", 512).intValue();
int predictionOrder = Integer.getInteger("signalproc.lpcanalysissynthesis.predictionorder", 20).intValue();
FrameOverlapAddSource foas = new FrameOverlapAddSource(signal, Window.HANNING, true, frameLength, samplingRate,
new LPCAnalysisResynthesis(predictionOrder));
DDSAudioInputStream outputAudio = new DDSAudioInputStream(new BufferedDoubleDataSource(foas), inputAudio.getFormat());
String outFileName = args[i].substring(0, args[i].length() - 4) + "_lpc_ar.wav";
AudioSystem.write(outputAudio, AudioFileFormat.Type.WAVE, new File(outFileName));
}
}
}