001 /*
002 * Copyright (c) Andrey Kuznetsov. All Rights Reserved.
003 *
004 * http://uio.imagero.com
005 *
006 * Redistribution and use in source and binary forms, with or without
007 * modification, are permitted provided that the following conditions are met:
008 *
009 * o Redistributions of source code must retain the above copyright notice,
010 * this list of conditions and the following disclaimer.
011 *
012 * o Redistributions in binary form must reproduce the above copyright notice,
013 * this list of conditions and the following disclaimer in the documentation
014 * and/or other materials provided with the distribution.
015 *
016 * o Neither the name of Andrey Kuznetsov nor the names of
017 * its contributors may be used to endorse or promote products derived
018 * from this software without specific prior written permission.
019 *
020 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
021 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
022 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
023 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
024 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
025 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
026 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
027 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
028 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
029 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
030 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
031 */
032
033 package com.imagero.uio.io;
034
035 import java.io.IOException;
036
037 /**
038 * PackBits decoder
039 *
040 * @author Andrei Kouznetsov
041 */
042 public class RLE4InputStream extends RLEInputStream {
043
044 byte[] value = new byte[2];
045
046 BitInputStream bin;
047
048 byte[] buffer = new byte[128];
049 int bufferStart;
050 int bufferLength;
051
052 ByteArrayOutputStreamExt bout;
053 BitOutputStream bitOut;
054
055 public RLE4InputStream(BitInputStream in) {
056 super(in);
057 bin = in;
058 bin.setBitsToRead(4);
059 bout = new ByteArrayOutputStreamExt();
060 bitOut = new BitOutputStream(bout);
061 }
062
063 public int read() throws IOException {
064 if (bufferStart >= bufferLength) {
065 fillBuffer();
066 }
067 if (bufferStart >= bufferLength) {
068 return -1;
069 }
070 return buffer[bufferStart++];
071 }
072
073 private void fillBuffer() throws IOException {
074 if (bout.size() == 0) {
075 fillBufferImpl();
076 }
077 bufferStart = 0;
078 bufferLength = bout.drain(buffer);
079 }
080
081 private void fillBufferImpl() throws IOException {
082 int len = bin.read(8);
083 if (len == 0) {
084 int value = bin.read(8);
085 switch (value) {
086 case 0:
087 throw new EndOfLineException();
088 case 1:
089 finished = true;
090 throw new EndOfBitmapException();
091 case 2:
092 int x = bin.read(8);
093 int y = bin.read(8);
094 throw new DeltaRecordException(x, y);
095 default:
096 int skipCount = 0;
097 if ((value & 3) != 0) {
098 skipCount = (value + 3) / 4 * 4 - value;
099 }
100 for (int i = 0; i < value; i++) {
101 bitOut.write(bin.read(4), 4);
102 }
103 for (int i = 0; i < skipCount; i++) {
104 /*int ignored = */bin.read(4);
105 }
106 }
107 }
108 else {
109 value[0] = (byte) bin.read(4);
110 value[1] = (byte) bin.read(4);
111
112 for (int i = 0; i < len; i++) {
113 bitOut.write(value[i & 1], 4);
114 }
115 }
116 }
117 }