001/*
002 * $RCSfile: TIFFPackBitsDecompressor.java,v $
003 *
004 * 
005 * Copyright (c) 2005 Sun Microsystems, Inc. All  Rights Reserved.
006 * 
007 * Redistribution and use in source and binary forms, with or without
008 * modification, are permitted provided that the following conditions
009 * are met: 
010 * 
011 * - Redistribution of source code must retain the above copyright 
012 *   notice, this  list of conditions and the following disclaimer.
013 * 
014 * - Redistribution in binary form must reproduce the above copyright
015 *   notice, this list of conditions and the following disclaimer in 
016 *   the documentation and/or other materials provided with the
017 *   distribution.
018 * 
019 * Neither the name of Sun Microsystems, Inc. or the names of 
020 * contributors may be used to endorse or promote products derived 
021 * from this software without specific prior written permission.
022 * 
023 * This software is provided "AS IS," without a warranty of any 
024 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
025 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
026 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
027 * EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL 
028 * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF 
029 * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
030 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR 
031 * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
032 * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
033 * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
034 * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
035 * POSSIBILITY OF SUCH DAMAGES. 
036 * 
037 * You acknowledge that this software is not designed or intended for 
038 * use in the design, construction, operation or maintenance of any 
039 * nuclear facility. 
040 *
041 * $Revision: 1.1 $
042 * $Date: 2005/02/11 05:01:49 $
043 * $State: Exp $
044 */
045package com.github.jaiimageio.impl.plugins.tiff;
046
047import java.io.IOException;
048
049import com.github.jaiimageio.plugins.tiff.TIFFDecompressor;
050
051public class TIFFPackBitsDecompressor extends TIFFDecompressor {
052
053    private static final boolean DEBUG = false;
054
055    public TIFFPackBitsDecompressor() {
056    }
057
058    public int decode(byte[] srcData, int srcOffset,
059                      byte[] dstData, int dstOffset)
060        throws IOException {
061
062        int srcIndex = srcOffset;
063        int dstIndex = dstOffset;
064
065        int dstArraySize = dstData.length;
066        int srcArraySize = srcData.length;
067        try {
068            while (dstIndex < dstArraySize && srcIndex < srcArraySize) {
069                byte b = srcData[srcIndex++];
070            
071                if (b >= 0 && b <= 127) { // second test not needed?
072                    // Literal run packet
073                
074                    for (int i = 0; i < b + 1; i++) {
075                        dstData[dstIndex++] = srcData[srcIndex++];
076                    }
077                } else if (b <= -1 && b >= -127) {
078                    // 2-byte encoded run packet
079                    byte repeat = srcData[srcIndex++];
080                    for (int i = 0; i < (-b + 1); i++) {
081                        dstData[dstIndex++] = repeat;
082                    }
083                } else {
084                    // No-op packet, do nothing
085                    ++srcIndex;
086                }
087            }
088        } catch(ArrayIndexOutOfBoundsException e) {
089            if(reader instanceof TIFFImageReader) {
090                ((TIFFImageReader)reader).forwardWarningMessage
091                    ("ArrayIndexOutOfBoundsException ignored in TIFFPackBitsDecompressor.decode()");
092            }
093        }
094        
095        return dstIndex - dstOffset;
096    }
097
098    public void decodeRaw(byte[] b,
099                          int dstOffset,
100                          int bitsPerPixel,
101                          int scanlineStride) throws IOException {
102        stream.seek(offset);
103            
104        byte[] srcData = new byte[byteCount];
105        stream.readFully(srcData);
106
107        int bytesPerRow = (srcWidth*bitsPerPixel + 7)/8;
108        byte[] buf;
109        int bufOffset;
110        if(bytesPerRow == scanlineStride) {
111            buf = b;
112            bufOffset = dstOffset;
113        } else {
114            buf = new byte[bytesPerRow*srcHeight];
115            bufOffset = 0;
116        }
117
118        decode(srcData, 0, buf, bufOffset);
119
120        if(bytesPerRow != scanlineStride) {
121            if(DEBUG) {
122                System.out.println("bytesPerRow != scanlineStride");
123            }
124            int off = 0;
125            for (int y = 0; y < srcHeight; y++) {
126                System.arraycopy(buf, off, b, dstOffset, bytesPerRow);
127                off += bytesPerRow;
128                dstOffset += scanlineStride;
129            }
130        }
131    }
132}
133