org.tritonus.share.sampled.convert.TEncodingFormatConversionProvider Maven / Gradle / Ivy
/*
* TEncodingFormatConversionProvider.java
*
* This file is part of Tritonus: http://www.tritonus.org/
*/
/*
* Copyright (c) 2000 by Florian Bomers
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Library General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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 Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
/*
|<--- this code is formatted to fit into 80 columns --->|
*/
package org.tritonus.share.sampled.convert;
import java.util.Collection;
import java.util.Iterator;
import javax.sound.sampled.AudioFormat;
import org.tritonus.share.TDebug;
import org.tritonus.share.ArraySet;
// this class depends on handling of AudioSystem.NOT_SPECIFIED in AudioFormat.matches()
/**
* This is a base class for FormatConversionProviders that only
* change the encoding, i.e. they never
*
* - change the sample size in bits without changing the encoding
*
- change the sample rate
*
- change the number of channels
*
* It is assumed that each source format can be encoded to all
* target formats.
*
In the sourceFormats and targetFormats collections that are passed to
* the constructor of this class, fields may be set to AudioSystem.NOT_SPECIFIED.
* This means that it handles all values of that field, but cannot change it.
*
This class prevents that a conversion is done (e.g. for sample rates),
* because the overriding class specified AudioSystem.NOT_SPECIFIED as sample rate,
* meaning it handles all sample rates.
*
Overriding classes must implement at least
* AudioInputStream getAudioInputStream(AudioFormat targetFormat, AudioInputStream sourceStream)
* and provide a constructor that calls the protected constructor of this class.
*
* @author Florian Bomers
*/
public abstract class TEncodingFormatConversionProvider
extends TSimpleFormatConversionProvider
{
/** create an instance. The given formats can be set to null. */
protected TEncodingFormatConversionProvider(
Collection sourceFormats,
Collection targetFormats)
{
super(sourceFormats, targetFormats);
}
/**
* This implementation assumes that the converter can convert
* from each of its source formats to each of its target
* formats. If this is not the case, the converter has to
* override this method.
* When conversion is supported, for every target encoding,
* the fields sample size in bits, channels and sample rate are checked:
*
* - When a field in both the source and target format is AudioSystem.NOT_SPECIFIED,
* one instance of that targetFormat is returned with this field set to AudioSystem.NOT_SPECIFIED.
*
- When a field in sourceFormat is set and it is AudioSystem.NOT_SPECIFIED in the target format,
* the value of the field of source format is set in the returned format.
*
- The same applies for the other way round.
*
* For this, replaceNotSpecified(sourceFormat, targetFormat) in the base
* class TSimpleFormatConversionProvider is used - and accordingly, the frameSize
* is recalculated with getFrameSize(...) if a field with AudioSystem.NOT_SPECIFIED
* is replaced. Inheriting classes may wish to override this method if the
* default mode of calculating the frame size is not appropriate.
*/
@Override
public AudioFormat[] getTargetFormats(AudioFormat.Encoding targetEncoding, AudioFormat sourceFormat) {
if (TDebug.TraceAudioConverter) {
TDebug.out(">TEncodingFormatConversionProvider.getTargetFormats(AudioFormat.Encoding, AudioFormat):");
TDebug.out("checking if conversion possible");
TDebug.out("from: " + sourceFormat);
TDebug.out("to: " + targetEncoding);
}
if (isConversionSupported(targetEncoding, sourceFormat)) {
// TODO: check that no duplicates may occur...
ArraySet result=new ArraySet();
Iterator iterator = getCollectionTargetFormats().iterator();
while (iterator.hasNext()) {
AudioFormat targetFormat = iterator.next();
targetFormat=replaceNotSpecified(sourceFormat, targetFormat);
result.add(targetFormat);
}
if (TDebug.TraceAudioConverter) {
TDebug.out("< returning "+result.size()+" elements.");
}
return result.toArray(EMPTY_FORMAT_ARRAY);
} else {
if (TDebug.TraceAudioConverter) {
TDebug.out("< returning empty array.");
}
return EMPTY_FORMAT_ARRAY;
}
}
}
/*** TEncodingFormatConversionProvider.java ***/