/* * Copyright (c) 1999, 2011, 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.InputStream;import java.io.IOException; import java.util.Vector; import javax.sound.sampled.AudioFormat;import javax.sound.sampled.AudioSystem;import javax.sound.sampled.AudioInputStream;  /** * A-law encodes linear data, and decodes a-law data to linear data. * * @author Kara Kytle */public class AlawCodec extends SunCodec {     /* Tables used for A-law decoding */     final static byte ALAW_TABH[] = new byte[256];    final static byte ALAW_TABL[] = new byte[256];     private static final AudioFormat.Encoding[] alawEncodings = { AudioFormat.Encoding.ALAW, 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 input    = i ^ 0x55;            int mantissa = (input & 0xf ) << 4;            int segment  = (input & 0x70) >> 4;            int value    = mantissa+8;             if(segment>=1)                value+=0x100;            if(segment>1)                value <<= (segment -1);             if( (input & 0x80)==0 )                value = -value;             ALAW_TABL[i] = (byte)value;            ALAW_TABH[i] = (byte)(value>>8);        }    }      /**     * Constructs a new ALAW codec object.     */    public AlawCodec() {         super(alawEncodings, alawEncodings);    }     // NEW CODE     /**     */    public AudioFormat.Encoding[] getTargetEncodings(AudioFormat sourceFormat){         if( sourceFormat.getEncoding().equals( AudioFormat.Encoding.PCM_SIGNED )) {             if( sourceFormat.getSampleSizeInBits() == 16 ) {                 AudioFormat.Encoding enc[] = new AudioFormat.Encoding[1];                enc[0] = AudioFormat.Encoding.ALAW;                return enc;             } else {                return new AudioFormat.Encoding[0];            }        } else if( sourceFormat.getEncoding().equals( AudioFormat.Encoding.ALAW ) ) {             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( (targetEncoding.equals( AudioFormat.Encoding.PCM_SIGNED ) && sourceFormat.getEncoding().equals( AudioFormat.Encoding.ALAW)) ||            (targetEncoding.equals( AudioFormat.Encoding.ALAW) && sourceFormat.getEncoding().equals( AudioFormat.Encoding.PCM_SIGNED)) ) {                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( sourceEncoding.equals( AudioFormat.Encoding.ALAW ) &&                targetEncoding.equals( AudioFormat.Encoding.PCM_SIGNED ) ) {                 targetFormat = new AudioFormat( targetEncoding,                                                sourceFormat.getSampleRate(),                                                16,                                                sourceFormat.getChannels(),                                                2*sourceFormat.getChannels(),                                                sourceFormat.getSampleRate(),                                                sourceFormat.isBigEndian());             } else if( sourceEncoding.equals( AudioFormat.Encoding.PCM_SIGNED ) &&                       targetEncoding.equals( AudioFormat.Encoding.ALAW ) ) {                 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 AlawCodecStream(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 ( AudioFormat.Encoding.PCM_SIGNED.equals(inputFormat.getEncoding())) {            format = new AudioFormat(AudioFormat.Encoding.ALAW,                                     inputFormat.getSampleRate(),                                     8,                                     inputFormat.getChannels(),                                     inputFormat.getChannels(),                                     inputFormat.getSampleRate(),                                     false );            formats.addElement(format);        }         if (AudioFormat.Encoding.ALAW.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 AlawCodecStream extends AudioInputStream {         // tempBuffer required only for encoding (when encode is true)        private static final int tempBufferSize = 64;        private byte tempBuffer [] = null;         /**         * True to encode to a-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;         AlawCodecStream(AudioInputStream stream, AudioFormat outputFormat) {             super(stream, outputFormat, -1);             AudioFormat inputFormat = stream.getFormat();             // throw an IllegalArgumentException if not ok            if ( ! (isConversionSupported(outputFormat, inputFormat)) ) {                 throw new IllegalArgumentException("Unsupported conversion: " + inputFormat.toString() + " to " + outputFormat.toString());            }             //$$fb 2002-07-18: fix for 4714846: JavaSound ULAW (8-bit) encoder erroneously depends on endian-ness            boolean PCMIsBigEndian;             // determine whether we are encoding or decoding            if (AudioFormat.Encoding.ALAW.equals(inputFormat.getEncoding())) {                encode = false;                encodeFormat = inputFormat;                decodeFormat = outputFormat;                PCMIsBigEndian = outputFormat.isBigEndian();            } else {                encode = true;                encodeFormat = outputFormat;                decodeFormat = inputFormat;                PCMIsBigEndian = inputFormat.isBigEndian();                tempBuffer = new byte[tempBufferSize];            }             if (PCMIsBigEndian) {                tabByte1 = ALAW_TABH;                tabByte2 = ALAW_TABL;                highByte = 0;                lowByte  = 1;            } else {                tabByte1 = ALAW_TABL;                tabByte2 = ALAW_TABH;                highByte = 1;                lowByte  = 0;            }             // set the AudioInputStream length in frames if we know it            if (stream instanceof AudioInputStream) {                frameLength = ((AudioInputStream)stream).getFrameLength();            }             // set framePos to zero            framePos = 0;            frameSize = inputFormat.getFrameSize();            if( frameSize==AudioSystem.NOT_SPECIFIED ) {                frameSize=1;            }        }          /*         * $$jb 2/23/99         * Used to determine segment number in aLaw 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];            return (int)read(b, 0, b.length);        }          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 QUANT_MASK = 0xF;                short SEG_SHIFT = 4;                short mask;                short seg;                int adj;                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)( (tempBuffer[i + lowByte]) & 0xFF);                         if(sample >= 0) {                            mask = 0xD5;                        } else {                            mask = 0x55;                            sample = (short)(-sample - 8);                        }                        /* Convert the scaled magnitude to segment number. */                        seg = search(sample, seg_end, (short) 8);                        /*                         * Combine the sign, segment, quantization bits                         */                        if (seg >= 8) {  /* out of range, return maximum value. */                            enc = (byte) (0x7F ^ mask);                        } else {                            enc = (byte) (seg << SEG_SHIFT);                            if(seg < 2) {                                enc |= (byte) ( (sample >> 4) & QUANT_MASK);                            } else {                                enc |= (byte) ( (sample >> (seg + 3)) & QUANT_MASK );                            }                            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                    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);                 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++;                }                 if( readCount<0 ) {             // EOF or error                    return readCount;                }                 return (i - off);            }        }    } // end class AlawCodecStream} // end class ALAW