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	/*
	* Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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 General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package com.sun.media.sound;

	import java.io.IOException;

	import java.util.Vector;

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


	/**
	* U-law encodes linear data, and decodes u-law data to linear data.
	*
	* @author Kara Kytle
	*/
	public final class UlawCodec extends SunCodec {

	/* Tables used for U-law decoding */

	private final static byte[] ULAW_TABH = new byte[256];
	private final static byte[] ULAW_TABL = new byte[256];

	private static final AudioFormat.Encoding[] ulawEncodings = {AudioFormat.Encoding.ULAW,
	AudioFormat.Encoding.PCM_SIGNED};

	private static final short seg_end [] = {0xFF, 0x1FF, 0x3FF,
	0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF};

	/**
	* Initializes the decode tables
	*/
	static {
	for (int i=0;i<256;i++) {
	int ulaw = ~i;
	int t;

	ulaw &= 0xFF;
	t = ((ulaw & 0xf)<<3) + 132;
	t <<= ((ulaw & 0x70) >> 4);
	t = ( (ulaw&0x80) != 0 ) ? (132-t) : (t-132);

	ULAW_TABL[i] = (byte) (t&0xff);
	ULAW_TABH[i] = (byte) ((t>>8) & 0xff);
	}
	}


	/**
	* Constructs a new ULAW codec object.
	*/
	public UlawCodec() {
	super(ulawEncodings, ulawEncodings);
	}

	/**
	*/
	public AudioFormat.Encoding[] getTargetEncodings(AudioFormat sourceFormat){
	if( AudioFormat.Encoding.PCM_SIGNED.equals(sourceFormat.getEncoding()) ) {
	if( sourceFormat.getSampleSizeInBits() == 16 ) {
	AudioFormat.Encoding enc[] = new AudioFormat.Encoding[1];
	enc[0] = AudioFormat.Encoding.ULAW;
	return enc;
	} else {
	return new AudioFormat.Encoding[0];
	}
	} else if (AudioFormat.Encoding.ULAW.equals(sourceFormat.getEncoding())) {
	if (sourceFormat.getSampleSizeInBits() == 8) {
	AudioFormat.Encoding enc[] = new AudioFormat.Encoding[1];
	enc[0] = AudioFormat.Encoding.PCM_SIGNED;
	return enc;
	} else {
	return new AudioFormat.Encoding[0];
	}
	} else {
	return new AudioFormat.Encoding[0];
	}
	}


	/**
	*/
	public AudioFormat[] getTargetFormats(AudioFormat.Encoding targetEncoding, AudioFormat sourceFormat){
	if( (AudioFormat.Encoding.PCM_SIGNED.equals(targetEncoding)
	&& AudioFormat.Encoding.ULAW.equals(sourceFormat.getEncoding()))
	\|\|
	(AudioFormat.Encoding.ULAW.equals(targetEncoding)
	&& AudioFormat.Encoding.PCM_SIGNED.equals(sourceFormat.getEncoding()))) {
	return getOutputFormats(sourceFormat);
	} else {
	return new AudioFormat[0];
	}
	}

	/**
	*/
	public AudioInputStream getAudioInputStream(AudioFormat.Encoding targetEncoding, AudioInputStream sourceStream){
	AudioFormat sourceFormat = sourceStream.getFormat();
	AudioFormat.Encoding sourceEncoding = sourceFormat.getEncoding();

	if (sourceEncoding.equals(targetEncoding)) {
	return sourceStream;
	} else {
	AudioFormat targetFormat = null;
	if (!isConversionSupported(targetEncoding,sourceStream.getFormat())) {
	throw new IllegalArgumentException("Unsupported conversion: " + sourceStream.getFormat().toString() + " to " + targetEncoding.toString());
	}
	if (AudioFormat.Encoding.ULAW.equals(sourceEncoding) &&
	AudioFormat.Encoding.PCM_SIGNED.equals(targetEncoding) ) {
	targetFormat = new AudioFormat( targetEncoding,
	sourceFormat.getSampleRate(),
	16,
	sourceFormat.getChannels(),
	2*sourceFormat.getChannels(),
	sourceFormat.getSampleRate(),
	sourceFormat.isBigEndian());
	} else if (AudioFormat.Encoding.PCM_SIGNED.equals(sourceEncoding) &&
	AudioFormat.Encoding.ULAW.equals(targetEncoding)) {
	targetFormat = new AudioFormat( targetEncoding,
	sourceFormat.getSampleRate(),
	8,
	sourceFormat.getChannels(),
	sourceFormat.getChannels(),
	sourceFormat.getSampleRate(),
	false);
	} else {
	throw new IllegalArgumentException("Unsupported conversion: " + sourceStream.getFormat().toString() + " to " + targetEncoding.toString());
	}

	return getAudioInputStream( targetFormat, sourceStream );
	}
	}

	/**
	* use old code...
	*/
	public AudioInputStream getAudioInputStream(AudioFormat targetFormat, AudioInputStream sourceStream){
	return getConvertedStream(targetFormat, sourceStream);
	}


	// OLD CODE

	/**
	* Opens the codec with the specified parameters.
	* @param stream stream from which data to be processed should be read
	* @param outputFormat desired data format of the stream after processing
	* @return stream from which processed data may be read
	* @throws IllegalArgumentException if the format combination supplied is
	* not supported.
	*/
	/* public AudioInputStream getConvertedStream(AudioFormat outputFormat, AudioInputStream stream) { */
	private AudioInputStream getConvertedStream(AudioFormat outputFormat, AudioInputStream stream) {
	AudioInputStream cs = null;

	AudioFormat inputFormat = stream.getFormat();

	if( inputFormat.matches(outputFormat) ) {
	cs = stream;
	} else {
	cs = (AudioInputStream) (new UlawCodecStream(stream, outputFormat));
	}
	return cs;
	}

	/**
	* Obtains the set of output formats supported by the codec
	* given a particular input format.
	* If no output formats are supported for this input format,
	* returns an array of length 0.
	* @return array of supported output formats.
	*/
	/* public AudioFormat[] getOutputFormats(AudioFormat inputFormat) { */
	private AudioFormat[] getOutputFormats(AudioFormat inputFormat) {

	Vector formats = new Vector();
	AudioFormat format;

	if ((inputFormat.getSampleSizeInBits() == 16)
	&& AudioFormat.Encoding.PCM_SIGNED.equals(inputFormat.getEncoding())) {
	format = new AudioFormat(AudioFormat.Encoding.ULAW,
	inputFormat.getSampleRate(),
	8,
	inputFormat.getChannels(),
	inputFormat.getChannels(),
	inputFormat.getSampleRate(),
	false );
	formats.addElement(format);
	}

	if (AudioFormat.Encoding.ULAW.equals(inputFormat.getEncoding())) {
	format = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED,
	inputFormat.getSampleRate(),
	16,
	inputFormat.getChannels(),
	inputFormat.getChannels()*2,
	inputFormat.getSampleRate(),
	false );
	formats.addElement(format);

	format = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED,
	inputFormat.getSampleRate(),
	16,
	inputFormat.getChannels(),
	inputFormat.getChannels()*2,
	inputFormat.getSampleRate(),
	true );
	formats.addElement(format);
	}

	AudioFormat[] formatArray = new AudioFormat[formats.size()];
	for (int i = 0; i < formatArray.length; i++) {
	formatArray[i] = (AudioFormat)(formats.elementAt(i));
	}
	return formatArray;
	}


	class UlawCodecStream extends AudioInputStream {

	private static final int tempBufferSize = 64;
	private byte tempBuffer [] = null;

	/**
	* True to encode to u-law, false to decode to linear
	*/
	boolean encode = false;

	AudioFormat encodeFormat;
	AudioFormat decodeFormat;

	byte tabByte1[] = null;
	byte tabByte2[] = null;
	int highByte = 0;
	int lowByte = 1;

	UlawCodecStream(AudioInputStream stream, AudioFormat outputFormat) {
	super(stream, outputFormat, AudioSystem.NOT_SPECIFIED);

	AudioFormat inputFormat = stream.getFormat();

	// throw an IllegalArgumentException if not ok
	if (!(isConversionSupported(outputFormat, inputFormat))) {
	throw new IllegalArgumentException("Unsupported conversion: " + inputFormat.toString() + " to " + outputFormat.toString());
	}

	//$$fb 2002-07-18: fix for 4714846: JavaSound ULAW (8-bit) encoder erroneously depends on endian-ness
	boolean PCMIsBigEndian;

	// determine whether we are encoding or decoding
	if (AudioFormat.Encoding.ULAW.equals(inputFormat.getEncoding())) {
	encode = false;
	encodeFormat = inputFormat;
	decodeFormat = outputFormat;
	PCMIsBigEndian = outputFormat.isBigEndian();
	} else {
	encode = true;
	encodeFormat = outputFormat;
	decodeFormat = inputFormat;
	PCMIsBigEndian = inputFormat.isBigEndian();
	tempBuffer = new byte[tempBufferSize];
	}

	// setup tables according to byte order
	if (PCMIsBigEndian) {
	tabByte1 = ULAW_TABH;
	tabByte2 = ULAW_TABL;
	highByte = 0;
	lowByte = 1;
	} else {
	tabByte1 = ULAW_TABL;
	tabByte2 = ULAW_TABH;
	highByte = 1;
	lowByte = 0;
	}

	// set the AudioInputStream length in frames if we know it
	if (stream instanceof AudioInputStream) {
	frameLength = ((AudioInputStream)stream).getFrameLength();
	}
	// set framePos to zero
	framePos = 0;
	frameSize = inputFormat.getFrameSize();
	if (frameSize == AudioSystem.NOT_SPECIFIED) {
	frameSize = 1;
	}
	}


	/*
	* $$jb 2/23/99
	* Used to determine segment number in uLaw encoding
	*/
	private short search(short val, short table[], short size) {
	for(short i = 0; i < size; i++) {
	if (val <= table[i]) { return i; }
	}
	return size;
	}

	/**
	* Note that this won't actually read anything; must read in
	* two-byte units.
	*/
	public int read() throws IOException {
	byte[] b = new byte[1];
	if (read(b, 0, b.length) == 1) {
	return b[1] & 0xFF;
	}
	return -1;
	}

	public int read(byte[] b) throws IOException {
	return read(b, 0, b.length);
	}

	public int read(byte[] b, int off, int len) throws IOException {
	// don't read fractional frames
	if( len%frameSize != 0 ) {
	len -= (len%frameSize);
	}
	if (encode) {
	short BIAS = 0x84;
	short mask;
	short seg;
	int i;

	short sample;
	byte enc;

	int readCount = 0;
	int currentPos = off;
	int readLeft = len*2;
	int readLen = ( (readLeft>tempBufferSize) ? tempBufferSize : readLeft );

	while ((readCount = super.read(tempBuffer,0,readLen))>0) {
	for(i = 0; i < readCount; i+=2) {
	/* Get the sample from the tempBuffer */
	sample = (short)(( (tempBuffer[i + highByte]) << 8) & 0xFF00);
	sample \|= (short)( (short) (tempBuffer[i + lowByte]) & 0xFF);

	/* Get the sign and the magnitude of the value. */
	if(sample < 0) {
	sample = (short) (BIAS - sample);
	mask = 0x7F;
	} else {
	sample += BIAS;
	mask = 0xFF;
	}
	/* Convert the scaled magnitude to segment number. */
	seg = search(sample, seg_end, (short) 8);
	/*
	* Combine the sign, segment, quantization bits;
	* and complement the code word.
	*/
	if (seg >= 8) { /* out of range, return maximum value. */
	enc = (byte) (0x7F ^ mask);
	} else {
	enc = (byte) ((seg << 4) \| ((sample >> (seg+3)) & 0xF));
	enc ^= mask;
	}
	/* Now put the encoded sample where it belongs */
	b[currentPos] = enc;
	currentPos++;
	}
	/* And update pointers and counters for next iteration */
	readLeft -= readCount;
	readLen = ( (readLeft>tempBufferSize) ? tempBufferSize : readLeft );
	}
	if( currentPos==off && readCount<0 ) { // EOF or error on read
	return readCount;
	}
	return (currentPos - off); /* Number of bytes written to new buffer */
	} else {
	int i;
	int readLen = len/2;
	int readOffset = off + len/2;
	int readCount = super.read(b, readOffset, readLen);

	if(readCount<0) { // EOF or error
	return readCount;
	}
	for (i = off; i < (off + (readCount*2)); i+=2) {
	b[i] = (byte)tabByte1[b[readOffset] & 0xFF];
	b[i+1] = (byte)tabByte2[b[readOffset] & 0xFF];
	readOffset++;
	}
	return (i - off);
	}
	}
	} // end class UlawCodecStream

	} // end class ULAW

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