MpegFormatConversionProvider.java

/*
 *   MpegFormatConversionProvider.
 * 
 * JavaZOOM : mp3spi@javazoom.net
 * 			  http://www.javazoom.net
 * 
 * --------------------------------------------------------------------------- 
 *   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.
 * --------------------------------------------------------------------------
 */


package	javazoom.spi.mpeg.sampled.convert;


import java.util.Arrays;

import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;

import javazoom.spi.mpeg.sampled.file.MpegEncoding;

import org.tritonus.share.TDebug;
import org.tritonus.share.sampled.Encodings;
import org.tritonus.share.sampled.convert.TEncodingFormatConversionProvider;

/**
 * ConversionProvider for MPEG files.
  */
public class MpegFormatConversionProvider extends TEncodingFormatConversionProvider
{
	private static final AudioFormat.Encoding	MP3 = Encodings.getEncoding("MP3");
	private static final AudioFormat.Encoding	PCM_SIGNED = Encodings.getEncoding("PCM_SIGNED");

	private static final AudioFormat[]	INPUT_FORMATS =
	{
		// mono
		new AudioFormat(MP3, -1.0F, -1, 1, -1, -1.0F, false),
		new AudioFormat(MP3, -1.0F, -1, 1, -1, -1.0F, true),
		// stereo
		new AudioFormat(MP3, -1.0F, -1, 2, -1, -1.0F, false),
		new AudioFormat(MP3, -1.0F, -1, 2, -1, -1.0F, true),
	};


	private static final AudioFormat[]	OUTPUT_FORMATS =
	{
		// mono, 16 bit signed
		new AudioFormat(PCM_SIGNED, -1.0F, 16, 1, 2, -1.0F, false),
		new AudioFormat(PCM_SIGNED, -1.0F, 16, 1, 2, -1.0F, true),
		// stereo, 16 bit signed
		new AudioFormat(PCM_SIGNED, -1.0F, 16, 2, 4, -1.0F, false),
		new AudioFormat(PCM_SIGNED, -1.0F, 16, 2, 4, -1.0F, true),
	};

	/**	
	 * Constructor.
	 */
	public MpegFormatConversionProvider()
	{
		super(Arrays.asList(INPUT_FORMATS), Arrays.asList(OUTPUT_FORMATS));
		if (TDebug.TraceAudioConverter) 
		{
			TDebug.out(">MpegFormatConversionProvider()");
		}
	}

	public AudioInputStream getAudioInputStream(AudioFormat targetFormat, AudioInputStream audioInputStream)
	{
		if (TDebug.TraceAudioConverter) 
		{
			TDebug.out(">MpegFormatConversionProvider.getAudioInputStream(AudioFormat targetFormat, AudioInputStream audioInputStream):");
		}
		return new DecodedMpegAudioInputStream(targetFormat, audioInputStream);
	}

	/**
	 * Add conversion support for any MpegEncoding source with FrameRate or FrameSize not empty.
	 * @param targetFormat
	 * @param sourceFormat
	 * @return
	 */
	public boolean isConversionSupported(AudioFormat targetFormat, AudioFormat sourceFormat)
	{
		if (TDebug.TraceAudioConverter) 
		{
					TDebug.out(">MpegFormatConversionProvider.isConversionSupported(AudioFormat targetFormat, AudioFormat sourceFormat):");
					TDebug.out("checking if conversion possible");
					TDebug.out("from: " + sourceFormat);
					TDebug.out("to: " + targetFormat);
		}

		boolean conversion = super.isConversionSupported(targetFormat, sourceFormat);
		if (conversion == false)
		{
			AudioFormat.Encoding enc = sourceFormat.getEncoding();
			if (enc instanceof MpegEncoding)
			{
				if ((sourceFormat.getFrameRate() != AudioSystem.NOT_SPECIFIED) || (sourceFormat.getFrameSize() != AudioSystem.NOT_SPECIFIED))
				{
					conversion = true;
				}
			}
		}
		return conversion;
	}
}