rockbox/songdbj/org/tritonus/file/gsm/GSMAudioFileReader.java
Michiel Van Der Kolk 9fee0ec4ca Songdb java version, source. only 1.5 compatible
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7101 a1c6a512-1295-4272-9138-f99709370657
2005-07-11 15:42:37 +00:00

142 lines
4 KiB
Java

/*
* GSMAudioFileReader.java
*
* This file is part of Tritonus: http://www.tritonus.org/
*/
/*
* Copyright (c) 1999 - 2004 by Matthias Pfisterer
* Copyright (c) 2001 by Florian Bomers <http://www.bomers.de>
*
* 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.sampled.file.gsm;
import java.io.InputStream;
import java.io.IOException;
import java.io.EOFException;
import java.util.HashMap;
import java.util.Map;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioFileFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.UnsupportedAudioFileException;
import javax.sound.sampled.spi.AudioFileReader;
import org.tritonus.share.TDebug;
import org.tritonus.share.sampled.file.TAudioFileFormat;
import org.tritonus.share.sampled.file.TAudioFileReader;
/** AudioFileReader class for GSM 06.10 data.
@author Matthias Pfisterer
*/
public class GSMAudioFileReader
extends TAudioFileReader
{
private static final int GSM_MAGIC = 0xD0;
private static final int GSM_MAGIC_MASK = 0xF0;
private static final int MARK_LIMIT = 1;
public GSMAudioFileReader()
{
super(MARK_LIMIT, true);
}
protected AudioFileFormat getAudioFileFormat(InputStream inputStream, long lFileSizeInBytes)
throws UnsupportedAudioFileException, IOException
{
if (TDebug.TraceAudioFileReader) { TDebug.out("GSMAudioFileReader.getAudioFileFormat(): begin"); }
int b0 = inputStream.read();
if (b0 < 0)
{
throw new EOFException();
}
/*
* Check for magic number.
*/
if ((b0 & GSM_MAGIC_MASK) != GSM_MAGIC)
{
throw new UnsupportedAudioFileException("not a GSM stream: wrong magic number");
}
/*
If the file size is known, we derive the number of frames
('frame size') from it.
If the values don't fit into integers, we leave them at
NOT_SPECIFIED. 'Unknown' is considered less incorrect than
a wrong value.
*/
// [fb] not specifying it causes Sun's Wave file writer to write rubbish
int nByteSize = AudioSystem.NOT_SPECIFIED;
int nFrameSize = AudioSystem.NOT_SPECIFIED;
Map<String, Object> properties = new HashMap<String, Object>();
if (lFileSizeInBytes != AudioSystem.NOT_SPECIFIED)
{
// the number of GSM frames
long lFrameSize = lFileSizeInBytes / 33;
// duration in microseconds
long lDuration = lFrameSize * 20000;
properties.put("duration", lDuration);
if (lFileSizeInBytes <= Integer.MAX_VALUE)
{
nByteSize = (int) lFileSizeInBytes;
nFrameSize = (int) (lFileSizeInBytes / 33);
}
}
Map<String, Object> afProperties = new HashMap<String, Object>();
afProperties.put("bitrate", 13200L);
AudioFormat format = new AudioFormat(
new AudioFormat.Encoding("GSM0610"),
8000.0F,
AudioSystem.NOT_SPECIFIED /* ??? [sample size in bits] */,
1,
33,
50.0F,
true, // this value is chosen arbitrarily
afProperties);
AudioFileFormat audioFileFormat =
new TAudioFileFormat(
new AudioFileFormat.Type("GSM","gsm"),
format,
nFrameSize,
nByteSize,
properties);
if (TDebug.TraceAudioFileReader) { TDebug.out("GSMAudioFileReader.getAudioFileFormat(): end"); }
return audioFileFormat;
}
}
/*** GSMAudioFileReader.java ***/