//
// LZOCodec.java
//
/*
LOCI Bio-Formats package for reading and converting biological file formats.
Copyright (C) 2005-@year@ Melissa Linkert, Curtis Rueden, Chris Allan,
Eric Kjellman and Brian Loranger.
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package loci.formats.codec;
import loci.formats.FormatException;
/**
* This class implements LZO decompression. Compression is not yet
* implemented.
*
* <dl><dt><b>Source code:</b></dt>
* <dd><a href="https://skyking.microscopy.wisc.edu/trac/java/browser/trunk/loci/formats/codec/LZOCodec.java">Trac</a>,
* <a href="https://skyking.microscopy.wisc.edu/svn/java/trunk/loci/formats/codec/LZOCodec.java">SVN</a></dd></dl>
*
* @author Melissa Linkert linkert at wisc.edu
*/
public class LZOCodec extends BaseCodec implements Codec {
// LZO compression codes
private static final int LZO_OVERRUN = -6;
/**
* Compresses a block of lzo data. Currently not supported.
*
* @param data the data to be compressed
* @param x length of the x dimension of the image data, if appropriate
* @param y length of the y dimension of the image data, if appropriate
* @param dims the dimensions of the image data, if appropriate
* @param options options to be used during compression, if appropriate
* @return The compressed data
* @throws FormatException If input is not an LZO-compressed data block.
*/
public byte[] compress(byte[] data, int x, int y,
int[] dims, Object options) throws FormatException
{
// TODO: Add LZO compression support.
throw new FormatException("LZO Compression not currently supported");
}
/**
* Decodes an LZO-compressed array.
* Adapted from LZO for Java, available at
* http://www.oberhumer.com/opensource/lzo/
*
* @param src the data to be decompressed
* @return The decompressed data
* @throws FormatException if data is not valid compressed data for this
* decompressor
*/
public byte[] decompress(byte[] src, Object options) throws FormatException {
int ip = 0;
int op = 0;
byte[] dst = new byte[src.length];
int t = src[ip++] & 0xff;
int mPos;
if (t > 17) {
t -= 17;
// do dst[op++] = src[ip++]; while (--t > 0);
do {
dst[op++] = src[ip++];
if(op == dst.length) {
byte[] newdst = new byte[dst.length * 2];
System.arraycopy(dst, 0, newdst, 0, dst.length);
dst = newdst;
}
} while (--t > 0);
t = src[ip++] & 0xff;
// if (t < 16) return;
if(t < 16) {
byte[] newdst = new byte[op];
System.arraycopy(dst, 0, newdst, 0, op);
return newdst;
}
}
loop:
for (;; t = src[ip++] & 0xff) {
if (t < 16) {
if (t == 0) {
while (src[ip] == 0) {
t += 255;
ip++;
}
t += 15 + (src[ip++] & 0xff);
}
t += 3;
// do dst[op++] = src[ip++]; while (--t > 0);
do {
dst[op++] = src[ip++];
if(op == dst.length) {
byte[] newdst = new byte[dst.length * 2];
System.arraycopy(dst, 0, newdst, 0, dst.length);
dst = newdst;
}
} while (--t > 0);
t = src[ip++] & 0xff;
if (t < 16) {
mPos = op - 0x801 - (t >> 2) - ((src[ip++] & 0xff) << 2);
if (mPos < 0) {
t = LZO_OVERRUN;
break loop;
}
t = 3;
do {
dst[op++] = dst[mPos++];
if(op == dst.length || mPos == dst.length) {
byte[] newdst = new byte[dst.length * 2];
System.arraycopy(dst, 0, newdst, 0, dst.length);
dst = newdst;
}
} while (--t > 0);
// do dst[op++] = dst[mPos++]; while (--t > 0);
t = src[ip - 2] & 3;
if (t == 0) continue;
// do dst[op++] = src[ip++]; while (--t > 0);
do {
dst[op++] = src[ip++];
if(op == dst.length) {
byte[] newdst = new byte[dst.length * 2];
System.arraycopy(dst, 0, newdst, 0, dst.length);
dst = newdst;
}
} while (--t > 0);
t = src[ip++] & 0xff;
}
}
for (;; t = src[ip++] & 0xff) {
if (t >= 64) {
mPos = op - 1 - ((t >> 2) & 7) - ((src[ip++] & 0xff) << 3);
t = (t >> 5) - 1;
}
else if (t >= 32) {
t &= 31;
if (t == 0) {
while (src[ip] == 0) {
t += 255;
ip++;
}
t += 31 + (src[ip++] & 0xff);
}
mPos = op - 1 - ((src[ip++] & 0xff) >> 2);
mPos -= ((src[ip++] & 0xff) << 6);
}
else if (t >= 16) {
mPos = op - ((t & 8) << 11);
t &= 7;
if (t == 0) {
while (src[ip] == 0) {
t += 255;
ip++;
}
t += 7 + (src[ip++] & 0xff);
}
mPos -= ((src[ip++] & 0xff) >> 2);
mPos -= ((src[ip++] & 0xff) << 6);
if (mPos == op) break loop;
mPos -= 0x4000;
}
else {
mPos = op - 1 - (t >> 2) - ((src[ip++] & 0xff) << 2);
t = 0;
}
if (mPos < 0) {
t = LZO_OVERRUN;
break loop;
}
t += 2;
// do dst[op++] = dst[mPos++]; while (--t > 0);
do {
dst[op++] = dst[mPos++];
if(op == dst.length || mPos == dst.length) {
byte[] newdst = new byte[dst.length * 2];
System.arraycopy(dst, 0, newdst, 0, dst.length);
dst = newdst;
}
} while (--t > 0);
t = src[ip - 2] & 3;
if (t == 0) break;
// do dst[op++] = src[ip++]; while (--t > 0);
do {
dst[op++] = src[ip++];
if(op == dst.length) {
byte[] newdst = new byte[dst.length * 2];
System.arraycopy(dst, 0, newdst, 0, dst.length);
dst = newdst;
}
} while (--t > 0);
}
}
byte[] newdst = new byte[op];
System.arraycopy(dst, 0, newdst, 0, op);
return newdst;
}
}