/**
 * Copyright 2007 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.effects;

import marytts.util.data.DoubleDataSource;
import marytts.util.math.MathUtils;

/**
 * @author Oytun Türk
 */
public class HMMDurationScaleEffect extends BaseAudioEffect {
	public float durScale;
	public static float NO_MODIFICATION = 1.0f;
	public static float DEFAULT_DUR_SCALE = 1.5f;
	public static float MAX_DUR_SCALE = 3.0f;
	public static float MIN_DUR_SCALE = 0.1f;

	public HMMDurationScaleEffect() {
		super(16000);

		setHMMEffect(true);

		setExampleParameters("durScale" + chParamEquals + Float.toString(DEFAULT_DUR_SCALE) + chParamSeparator);
	}

	public void parseParameters(String param) {
		super.parseParameters(param);

		durScale = expectFloatParameter("durScale");

		if (durScale == NULL_FLOAT_PARAM)
			durScale = DEFAULT_DUR_SCALE;

		durScale = MathUtils.CheckLimits(durScale, MIN_DUR_SCALE, MAX_DUR_SCALE);
	}

	// Actual processing is done within the HMM synthesizer so do nothing here
	public DoubleDataSource process(DoubleDataSource input) {
		return input;
	}

	public String getHelpText() {

		String strHelp = "Duration scaling for HMM voices:" + strLineBreak
				+ "Scales the HMM output speech duration by <durScale>." + strLineBreak + "Parameter:" + strLineBreak
				+ "   <durScale>" + "   Definition : Duration scaling factor for synthesized speech output" + strLineBreak
				+ "   Range      : [" + String.valueOf(MIN_DUR_SCALE) + "," + String.valueOf(MAX_DUR_SCALE) + "]" + strLineBreak
				+ "Example:" + strLineBreak + getExampleParameters();

		return strHelp;
	}

	public String getName() {
		return "Rate";
	}
}