--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2000, 2005 IBM Corporation and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.swt.internal.image;
+
+import org.eclipse.swt.*;
+
+/*
+* Decoder for
+* - CCITT Group 3 1-Dimensional Modified Huffman run length encoding
+* (TIFF compression type 2)
+* - CCITT T.4 bi-level encoding 1D
+* (TIFF compression type 3 option 1D)
+*/
+final class TIFFModifiedHuffmanCodec {
+ static final short[][][] BLACK_CODE = {
+ /* 2 bits */
+ {{2, 3}, {3, 2}},
+ /* 3 bits */
+ {{2, 1}, {3, 4}},
+ /* 4 bits */
+ {{2, 6}, {3, 5}},
+ /* 5 bits */
+ {{3, 7}},
+ /* 6 bits */
+ {{4, 9}, {5, 8}},
+ /* 7 bits */
+ {{4, 10}, {5, 11}, {7, 12}},
+ /* 8 bits */
+ {{4, 13}, {7, 14}},
+ /* 9 bits */
+ {{24, 15}},
+ /* 10 bits */
+ {{8, 18}, {15, 64}, {23, 16}, {24, 17}, {55, 0}},
+ /* 11 bits */
+ {/* EOL */{0, -1}, {8, 1792}, {23, 24}, {24, 25}, {40, 23}, {55, 22}, {103, 19},
+ {104, 20}, {108, 21}, {12, 1856}, {13, 1920}},
+ /* 12 bits */
+ {{18, 1984}, {19, 2048}, {20, 2112}, {21, 2176}, {22, 2240}, {23, 2304},
+ {28, 2368}, {29, 2432}, {30, 2496}, {31, 2560}, {36, 52}, {39, 55}, {40, 56},
+ {43, 59}, {44, 60}, {51, 320}, {52, 384}, {53, 448}, {55, 53}, {56, 54}, {82, 50},
+ {83, 51}, {84, 44}, {85, 45}, {86, 46}, {87, 47}, {88, 57}, {89, 58}, {90, 61},
+ {91, 256}, {100, 48}, {101, 49}, {102, 62}, {103, 63}, {104, 30}, {105, 31},
+ {106, 32}, {107, 33}, {108, 40}, {109, 41}, {200, 128}, {201, 192}, {202, 26},
+ {203, 27}, {204, 28}, {205, 29}, {210, 34}, {211, 35}, {212, 36}, {213, 37},
+ {214, 38}, {215, 39}, {218, 42}, {219, 43}},
+ /* 13 bits */
+ {{74, 640}, {75, 704}, {76, 768}, {77, 832}, {82, 1280}, {83, 1344}, {84, 1408},
+ {85, 1472}, {90, 1536}, {91, 1600}, {100, 1664}, {101, 1728}, {108, 512},
+ {109, 576}, {114, 896}, {115, 960}, {116, 1024}, {117, 1088}, {118, 1152},
+ {119, 1216}}
+ };
+
+ static final short[][][] WHITE_CODE = {
+ /* 4 bits */
+ {{7, 2}, {8, 3}, {11, 4}, {12, 5}, {14, 6}, {15, 7}},
+ /* 5 bits */
+ {{7, 10}, {8, 11}, {18, 128}, {19, 8}, {20, 9}, {27, 64}},
+ /* 6 bits */
+ {{3, 13}, {7, 1}, {8, 12}, {23, 192}, {24, 1664}, {42, 16}, {43, 17}, {52, 14},
+ {53, 15}},
+ /* 7 bits */
+ {{3, 22}, {4, 23}, {8, 20}, {12, 19}, {19, 26}, {23, 21}, {24, 28}, {36, 27},
+ {39, 18}, {40, 24}, {43, 25}, {55, 256}},
+ /* 8 bits */
+ {{2, 29}, {3, 30}, {4, 45}, {5, 46}, {10, 47}, {11, 48}, {18, 33}, {19, 34},
+ {20, 35}, {21, 36}, {22, 37}, {23, 38}, {26, 31}, {27, 32}, {36, 53}, {37, 54},
+ {40, 39}, {41, 40}, {42, 41}, {43, 42}, {44, 43}, {45, 44}, {50, 61}, {51, 62},
+ {52, 63}, {53, 0}, {54, 320}, {55, 384}, {74, 59}, {75, 60}, {82, 49}, {83, 50},
+ {84, 51}, {85, 52}, {88, 55}, {89, 56}, {90, 57}, {91, 58}, {100, 448},
+ {101, 512}, {103, 640}, {104, 576}},
+ /* 9 bits */
+ {{152, 1472}, {153, 1536}, {154, 1600}, {155, 1728}, {204, 704}, {205, 768},
+ {210, 832}, {211, 896}, {212, 960}, {213, 1024}, {214, 1088}, {215, 1152},
+ {216, 1216}, {217, 1280}, {218, 1344}, {219, 1408}},
+ /* 10 bits */
+ {},
+ /* 11 bits */
+ {{8, 1792}, {12, 1856}, {13, 1920}},
+ /* 12 bits */
+ {/* EOL */{1, -1}, {18, 1984}, {19, 2048}, {20, 2112}, {21, 2176}, {22, 2240}, {23, 2304},
+ {28, 2368}, {29, 2432}, {30, 2496}, {31, 2560}}
+ };
+
+ static final int BLACK_MIN_BITS = 2;
+ static final int WHITE_MIN_BITS = 4;
+
+ boolean isWhite;
+ int whiteValue = 0;
+ int blackValue = 1;
+ byte[] src;
+ byte[] dest;
+ int byteOffsetSrc = 0;
+ int bitOffsetSrc = 0;
+ int byteOffsetDest = 0;
+ int bitOffsetDest = 0;
+ int code = 0;
+ int nbrBits = 0;
+ /* nbr of bytes per row */
+ int rowSize;
+
+public int decode(byte[] src, byte[] dest, int offsetDest, int rowSize, int nRows) {
+ this.src = src;
+ this.dest = dest;
+ this.rowSize = rowSize;
+ byteOffsetSrc = 0;
+ bitOffsetSrc = 0;
+ byteOffsetDest = offsetDest;
+ bitOffsetDest = 0;
+ int cnt = 0;
+ while (cnt < nRows && decodeRow()) {
+ cnt++;
+ /* byte aligned */
+ if (bitOffsetDest > 0) {
+ byteOffsetDest++;
+ bitOffsetDest = 0;
+ }
+ }
+ return byteOffsetDest - offsetDest;
+}
+
+boolean decodeRow() {
+ isWhite = true;
+ int n = 0;
+ while (n < rowSize) {
+ int runLength = decodeRunLength();
+ if (runLength < 0) return false;
+ n += runLength;
+ setNextBits(isWhite ? whiteValue : blackValue, runLength);
+ isWhite = !isWhite;
+ }
+ return true;
+}
+
+int decodeRunLength() {
+ int runLength = 0;
+ int partialRun = 0;
+ short[][][] huffmanCode = isWhite ? WHITE_CODE : BLACK_CODE;
+ while (true) {
+ boolean found = false;
+ nbrBits = isWhite ? WHITE_MIN_BITS : BLACK_MIN_BITS;
+ code = getNextBits(nbrBits);
+ for (int i = 0; i < huffmanCode.length; i++) {
+ for (int j = 0; j < huffmanCode[i].length; j++) {
+ if (huffmanCode[i][j][0] == code) {
+ found = true;
+ partialRun = huffmanCode[i][j][1];
+ if (partialRun == -1) {
+ /* Stop when reaching final EOL on last byte */
+ if (byteOffsetSrc == src.length - 1) return -1;
+ /* Group 3 starts each row with an EOL - ignore it */
+ } else {
+ runLength += partialRun;
+ if (partialRun < 64) return runLength;
+ }
+ break;
+ }
+ }
+ if (found) break;
+ code = code << 1 | getNextBit();
+ }
+ if (!found) SWT.error(SWT.ERROR_INVALID_IMAGE);
+ }
+}
+
+int getNextBit() {
+ int value = (src[byteOffsetSrc] >>> (7 - bitOffsetSrc)) & 0x1;
+ bitOffsetSrc++;
+ if (bitOffsetSrc > 7) {
+ byteOffsetSrc++;
+ bitOffsetSrc = 0;
+ }
+ return value;
+}
+
+int getNextBits(int cnt) {
+ int value = 0;
+ for (int i = 0; i < cnt; i++) {
+ value = value << 1 | getNextBit();
+ }
+ return value;
+}
+
+void setNextBits(int value, int cnt) {
+ int n = cnt;
+ while (bitOffsetDest > 0 && bitOffsetDest <= 7 && n > 0) {
+ dest[byteOffsetDest] = value == 1 ?
+ (byte)(dest[byteOffsetDest] | (1 << (7 - bitOffsetDest))) :
+ (byte)(dest[byteOffsetDest] & ~(1 << (7 - bitOffsetDest)));
+ n--;
+ bitOffsetDest++;
+ }
+ if (bitOffsetDest == 8) {
+ byteOffsetDest++;
+ bitOffsetDest = 0;
+ }
+ while (n >= 8) {
+ dest[byteOffsetDest++] = (byte) (value == 1 ? 0xFF : 0);
+ n -= 8;
+ }
+ while (n > 0) {
+ dest[byteOffsetDest] = value == 1 ?
+ (byte)(dest[byteOffsetDest] | (1 << (7 - bitOffsetDest))) :
+ (byte)(dest[byteOffsetDest] & ~(1 << (7 - bitOffsetDest)));
+ n--;
+ bitOffsetDest++;
+ }
+}
+
+}
Code Review / simantics / platform.git / blobdiff