/**
* Java Modular Image Synthesis Toolkit (JMIST)
* Copyright (C) 2008-2013 Bradley W. Kimmel
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
package ca.eandb.jmist.framework.loader.openexr.codec;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.InflaterOutputStream;
import javax.imageio.stream.IIOByteBuffer;
import ca.eandb.jmist.framework.loader.openexr.attribute.Box2i;
import ca.eandb.util.UnexpectedException;
/**
* @author brad
*
*/
public final class FlateCodec implements Codec {
private static final FlateCodec INSTANCE = new FlateCodec();
public static FlateCodec getInstance() {
return INSTANCE;
}
private FlateCodec() {}
/* (non-Javadoc)
* @see ca.eandb.jmist.framework.loader.openexr.codec.Codec#compress(javax.imageio.stream.IIOByteBuffer, ca.eandb.jmist.framework.loader.openexr.attribute.Box2i)
*/
@Override
public void compress(IIOByteBuffer buf, Box2i range) {
try {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
DeflaterOutputStream inf = new DeflaterOutputStream(bytes);
int n = buf.getLength();
byte[] data = buf.getData();
byte[] pred = new byte[n];
int t1 = 0;
int t2 = (n + 1) / 2;
int s = buf.getOffset();
int stop = s + n;
while (true) {
if (s < stop) {
pred[t1++] = data[s++];
} else {
break;
}
if (s < stop) {
pred[t2++] = data[s++];
} else {
break;
}
}
int p = pred[0];
for (int i = 1; i < n; i++) {
int d = (int) pred[i] - p + (128 + 256);
p = pred[i];
pred[i] = (byte) d;
}
inf.write(pred);
inf.close();
buf.setData(bytes.toByteArray());
buf.setOffset(0);
buf.setLength(bytes.size());
} catch (IOException e) {
throw new UnexpectedException(e);
}
}
/* (non-Javadoc)
* @see ca.eandb.jmist.framework.loader.openexr.codec.Codec#decompress(javax.imageio.stream.IIOByteBuffer, ca.eandb.jmist.framework.loader.openexr.attribute.Box2i)
*/
@Override
public void decompress(IIOByteBuffer buf, Box2i range) {
try {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
InflaterOutputStream inf = new InflaterOutputStream(bytes);
inf.write(buf.getData(), buf.getOffset(), buf.getLength());
inf.close();
byte[] data = bytes.toByteArray();
for (int i = 1, n = bytes.size(); i < n; i++) {
data[i] = (byte) (((int) data[i - 1]) + ((int) data[i]) - 128);
}
int n = bytes.size();
int t1 = 0;
int t2 = (n + 1) / 2;
int s = 0;
byte[] out = new byte[n];
while (true) {
if (s < n) {
out[s++] = data[t1++];
} else {
break;
}
if (s < n) {
out[s++] = data[t2++];
} else {
break;
}
}
buf.setData(out);
buf.setOffset(0);
buf.setLength(n);
} catch (IOException e) {
throw new UnexpectedException(e);
}
}
}