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Link Here
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--- ipelib/ipedct.cpp.orig |
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--- ipelib/ipedct.cpp.orig |
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+++ ipelib/ipedct.cpp |
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+++ ipelib/ipedct.cpp |
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@@ -31,6 +31,7 @@ |
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@@ -0,0 +1,1465 @@ |
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*/ |
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+//------------------------------------------------------------------------ |
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|
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+// Decoding a DCT stream (JPEG image) |
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#include "ipebase.h" |
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+// This code has been taken from Xpdf, |
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+#include <sys/types.h> |
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+// Copyright 1996-2002 Glyph & Cog, LLC |
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|
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+//------------------------------------------------------------------------ |
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using namespace ipe; |
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+/* |
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|
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+ |
|
|
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+ This file is part of the extensible drawing editor Ipe. |
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+ Copyright (C) 1993-2013 Otfried Cheong |
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+ |
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+ Ipe is free software; you can redistribute it and/or modify it |
| 15 |
+ under the terms of the GNU General Public License as published by |
| 16 |
+ the Free Software Foundation; either version 3 of the License, or |
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+ (at your option) any later version. |
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+ |
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+ As a special exception, you have permission to link Ipe with the |
| 20 |
+ CGAL library and distribute executables, as long as you follow the |
| 21 |
+ requirements of the Gnu General Public License in regard to all of |
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+ the software in the executable aside from CGAL. |
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+ |
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+ Ipe is distributed in the hope that it will be useful, but WITHOUT |
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+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
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+ or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public |
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+ License for more details. |
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+ |
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+ You should have received a copy of the GNU General Public License |
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+ along with Ipe; if not, you can find it at |
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+ "http://www.gnu.org/copyleft/gpl.html", or write to the Free |
| 32 |
+ Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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+ |
| 34 |
+*/ |
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+ |
| 36 |
+#include "ipebase.h" |
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+ |
| 38 |
+using namespace ipe; |
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+ |
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+// -------------------------------------------------------------------- |
| 41 |
+ |
| 42 |
+// DCT component info |
| 43 |
+struct DCTCompInfo { |
| 44 |
+ int id; // component ID |
| 45 |
+ int hSample, vSample; // horiz/vert sampling resolutions |
| 46 |
+ int quantTable; // quantization table number |
| 47 |
+ int prevDC; // DC coefficient accumulator |
| 48 |
+}; |
| 49 |
+ |
| 50 |
+struct DCTScanInfo { |
| 51 |
+ bool comp[4]; // comp[i] is set if component i is |
| 52 |
+ // included in this scan |
| 53 |
+ int numComps; // number of components in the scan |
| 54 |
+ int dcHuffTable[4]; // DC Huffman table numbers |
| 55 |
+ int acHuffTable[4]; // AC Huffman table numbers |
| 56 |
+ int firstCoeff, lastCoeff; // first and last DCT coefficient |
| 57 |
+ int ah, al; // successive approximation parameters |
| 58 |
+}; |
| 59 |
+ |
| 60 |
+// DCT Huffman decoding table |
| 61 |
+struct DCTHuffTable { |
| 62 |
+ uchar firstSym[17]; // first symbol for this bit length |
| 63 |
+ ushort firstCode[17]; // first code for this bit length |
| 64 |
+ ushort numCodes[17]; // number of codes of this bit length |
| 65 |
+ uchar sym[256]; // symbols |
| 66 |
+}; |
| 67 |
+ |
| 68 |
+// -------------------------------------------------------------------- |
| 69 |
+ |
| 70 |
+class DCTStream { |
| 71 |
+public: |
| 72 |
+ |
| 73 |
+ DCTStream(DataSource &source); |
| 74 |
+ ~DCTStream(); |
| 75 |
+ void reset(); |
| 76 |
+ int getChar(); |
| 77 |
+ |
| 78 |
+private: |
| 79 |
+ DataSource &iSource; |
| 80 |
+ |
| 81 |
+ bool progressive; // set if in progressive mode |
| 82 |
+ bool interleaved; // set if in interleaved mode |
| 83 |
+ int width, height; // image size |
| 84 |
+ int mcuWidth, mcuHeight; // size of min coding unit, in data units |
| 85 |
+ int bufWidth, bufHeight; // frameBuf size |
| 86 |
+ DCTCompInfo compInfo[4]; // info for each component |
| 87 |
+ DCTScanInfo scanInfo; // info for the current scan |
| 88 |
+ int numComps; // number of components in image |
| 89 |
+ int colorXform; // need YCbCr-to-RGB transform? |
| 90 |
+ bool gotAdobeMarker; // set if APP14 Adobe marker was present |
| 91 |
+ int restartInterval; // restart interval, in MCUs |
| 92 |
+ uchar quantTables[4][64]; // quantization tables |
| 93 |
+ int numQuantTables; // number of quantization tables |
| 94 |
+ DCTHuffTable dcHuffTables[4]; // DC Huffman tables |
| 95 |
+ DCTHuffTable acHuffTables[4]; // AC Huffman tables |
| 96 |
+ int numDCHuffTables; // number of DC Huffman tables |
| 97 |
+ int numACHuffTables; // number of AC Huffman tables |
| 98 |
+ uchar *rowBuf[4][32]; // buffer for one MCU (non-progressive mode) |
| 99 |
+ int *frameBuf[4]; // buffer for frame (progressive mode) |
| 100 |
+ int comp, x, y, dy; // current position within image/MCU |
| 101 |
+ int restartCtr; // MCUs left until restart |
| 102 |
+ int restartMarker; // next restart marker |
| 103 |
+ int eobRun; // number of EOBs left in the current run |
| 104 |
+ int inputBuf; // input buffer for variable length codes |
| 105 |
+ int inputBits; // number of valid bits in input buffer |
| 106 |
+ |
| 107 |
+ void restart(); |
| 108 |
+ bool readMCURow(); |
| 109 |
+ void readScan(); |
| 110 |
+ bool readDataUnit(DCTHuffTable *dcHuffTable, |
| 111 |
+ DCTHuffTable *acHuffTable, |
| 112 |
+ int *prevDC, int data[64]); |
| 113 |
+ bool readProgressiveDataUnit(DCTHuffTable *dcHuffTable, |
| 114 |
+ DCTHuffTable *acHuffTable, |
| 115 |
+ int *prevDC, int data[64]); |
| 116 |
+ void decodeImage(); |
| 117 |
+ void transformDataUnit(uchar *quantTable, |
| 118 |
+ int dataIn[64], uchar dataOut[64]); |
| 119 |
+ int readHuffSym(DCTHuffTable *table); |
| 120 |
+ int readAmp(int size); |
| 121 |
+ int readBit(); |
| 122 |
+ bool readHeader(); |
| 123 |
+ bool readBaselineSOF(); |
| 124 |
+ bool readProgressiveSOF(); |
| 125 |
+ bool readScanInfo(); |
| 126 |
+ bool readQuantTables(); |
| 127 |
+ bool readHuffmanTables(); |
| 128 |
+ bool readRestartInterval(); |
| 129 |
+ bool readAdobeMarker(); |
| 130 |
+ bool readTrailer(); |
| 131 |
+ int readMarker(); |
| 132 |
+ int read16(); |
| 133 |
+}; |
| 134 |
+ |
| 135 |
+// -------------------------------------------------------------------- |
| 136 |
+ |
| 137 |
+// IDCT constants (20.12 fixed point format) |
| 138 |
+#define dctCos1 4017 // cos(pi/16) |
| 139 |
+#define dctSin1 799 // sin(pi/16) |
| 140 |
+#define dctCos3 3406 // cos(3*pi/16) |
| 141 |
+#define dctSin3 2276 // sin(3*pi/16) |
| 142 |
+#define dctCos6 1567 // cos(6*pi/16) |
| 143 |
+#define dctSin6 3784 // sin(6*pi/16) |
| 144 |
+#define dctSqrt2 5793 // sqrt(2) |
| 145 |
+#define dctSqrt1d2 2896 // sqrt(2) / 2 |
| 146 |
+ |
| 147 |
+// color conversion parameters (16.16 fixed point format) |
| 148 |
+#define dctCrToR 91881 // 1.4020 |
| 149 |
+#define dctCbToG -22553 // -0.3441363 |
| 150 |
+#define dctCrToG -46802 // -0.71413636 |
| 151 |
+#define dctCbToB 116130 // 1.772 |
| 152 |
+ |
| 153 |
+// clip [-256,511] --> [0,255] |
| 154 |
+#define dctClipOffset 256 |
| 155 |
+static uchar dctClip[768]; |
| 156 |
+static int dctClipInit = 0; |
| 157 |
+ |
| 158 |
+// zig zag decode map |
| 159 |
+static int dctZigZag[64] = { |
| 160 |
+ 0, |
| 161 |
+ 1, 8, |
| 162 |
+ 16, 9, 2, |
| 163 |
+ 3, 10, 17, 24, |
| 164 |
+ 32, 25, 18, 11, 4, |
| 165 |
+ 5, 12, 19, 26, 33, 40, |
| 166 |
+ 48, 41, 34, 27, 20, 13, 6, |
| 167 |
+ 7, 14, 21, 28, 35, 42, 49, 56, |
| 168 |
+ 57, 50, 43, 36, 29, 22, 15, |
| 169 |
+ 23, 30, 37, 44, 51, 58, |
| 170 |
+ 59, 52, 45, 38, 31, |
| 171 |
+ 39, 46, 53, 60, |
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+ 61, 54, 47, |
| 173 |
+ 55, 62, |
| 174 |
+ 63 |
| 175 |
+}; |
| 176 |
+ |
| 177 |
+// -------------------------------------------------------------------- |
| 178 |
+ |
| 179 |
+DCTStream::DCTStream(DataSource &source) |
| 180 |
+ : iSource(source) |
| 181 |
+{ |
| 182 |
+ int i, j; |
| 183 |
+ |
| 184 |
+ progressive = interleaved = false; |
| 185 |
+ width = height = 0; |
| 186 |
+ mcuWidth = mcuHeight = 0; |
| 187 |
+ numComps = 0; |
| 188 |
+ comp = 0; |
| 189 |
+ x = y = dy = 0; |
| 190 |
+ for (i = 0; i < 4; ++i) { |
| 191 |
+ for (j = 0; j < 32; ++j) { |
| 192 |
+ rowBuf[i][j] = 0; |
| 193 |
+ } |
| 194 |
+ frameBuf[i] = 0; |
| 195 |
+ } |
| 196 |
+ |
| 197 |
+ if (!dctClipInit) { |
| 198 |
+ for (i = -256; i < 0; ++i) |
| 199 |
+ dctClip[dctClipOffset + i] = 0; |
| 200 |
+ for (i = 0; i < 256; ++i) |
| 201 |
+ dctClip[dctClipOffset + i] = uchar(i); |
| 202 |
+ for (i = 256; i < 512; ++i) |
| 203 |
+ dctClip[dctClipOffset + i] = 255; |
| 204 |
+ dctClipInit = 1; |
| 205 |
+ } |
| 206 |
+} |
| 207 |
+ |
| 208 |
+DCTStream::~DCTStream() |
| 209 |
+{ |
| 210 |
+ int i, j; |
| 211 |
+ if (progressive || !interleaved) { |
| 212 |
+ for (i = 0; i < numComps; ++i) { |
| 213 |
+ delete [] frameBuf[i]; |
| 214 |
+ } |
| 215 |
+ } else { |
| 216 |
+ for (i = 0; i < numComps; ++i) { |
| 217 |
+ for (j = 0; j < mcuHeight; ++j) { |
| 218 |
+ delete [] rowBuf[i][j]; |
| 219 |
+ } |
| 220 |
+ } |
| 221 |
+ } |
| 222 |
+} |
| 223 |
+ |
| 224 |
+void DCTStream::reset() |
| 225 |
+{ |
| 226 |
+ int minHSample, minVSample; |
| 227 |
+ int i, j; |
| 228 |
+ |
| 229 |
+ progressive = interleaved = false; |
| 230 |
+ width = height = 0; |
| 231 |
+ numComps = 0; |
| 232 |
+ numQuantTables = 0; |
| 233 |
+ numDCHuffTables = 0; |
| 234 |
+ numACHuffTables = 0; |
| 235 |
+ colorXform = 0; |
| 236 |
+ gotAdobeMarker = false; |
| 237 |
+ restartInterval = 0; |
| 238 |
+ |
| 239 |
+ if (!readHeader()) { |
| 240 |
+ y = height; |
| 241 |
+ return; |
| 242 |
+ } |
| 243 |
+ |
| 244 |
+ // compute MCU size |
| 245 |
+ mcuWidth = minHSample = compInfo[0].hSample; |
| 246 |
+ mcuHeight = minVSample = compInfo[0].vSample; |
| 247 |
+ for (i = 1; i < numComps; ++i) { |
| 248 |
+ if (compInfo[i].hSample < minHSample) |
| 249 |
+ minHSample = compInfo[i].hSample; |
| 250 |
+ if (compInfo[i].vSample < minVSample) |
| 251 |
+ minVSample = compInfo[i].vSample; |
| 252 |
+ if (compInfo[i].hSample > mcuWidth) |
| 253 |
+ mcuWidth = compInfo[i].hSample; |
| 254 |
+ if (compInfo[i].vSample > mcuHeight) |
| 255 |
+ mcuHeight = compInfo[i].vSample; |
| 256 |
+ } |
| 257 |
+ for (i = 0; i < numComps; ++i) { |
| 258 |
+ compInfo[i].hSample /= minHSample; |
| 259 |
+ compInfo[i].vSample /= minVSample; |
| 260 |
+ } |
| 261 |
+ mcuWidth = (mcuWidth / minHSample) * 8; |
| 262 |
+ mcuHeight = (mcuHeight / minVSample) * 8; |
| 263 |
+ |
| 264 |
+ // figure out color transform |
| 265 |
+ if (!gotAdobeMarker && numComps == 3) { |
| 266 |
+ if (compInfo[0].id == 1 && compInfo[1].id == 2 && compInfo[2].id == 3) { |
| 267 |
+ colorXform = 1; |
| 268 |
+ } |
| 269 |
+ } |
| 270 |
+ |
| 271 |
+ if (progressive || !interleaved) { |
| 272 |
+ |
| 273 |
+ // allocate a buffer for the whole image |
| 274 |
+ bufWidth = ((width + mcuWidth - 1) / mcuWidth) * mcuWidth; |
| 275 |
+ bufHeight = ((height + mcuHeight - 1) / mcuHeight) * mcuHeight; |
| 276 |
+ for (i = 0; i < numComps; ++i) { |
| 277 |
+ frameBuf[i] = new int[bufWidth * bufHeight]; |
| 278 |
+ memset(frameBuf[i], 0, bufWidth * bufHeight * sizeof(int)); |
| 279 |
+ } |
| 280 |
+ |
| 281 |
+ // read the image data |
| 282 |
+ do { |
| 283 |
+ restartMarker = 0xd0; |
| 284 |
+ restart(); |
| 285 |
+ readScan(); |
| 286 |
+ } while (readHeader()); |
| 287 |
+ |
| 288 |
+ // decode |
| 289 |
+ decodeImage(); |
| 290 |
+ |
| 291 |
+ // initialize counters |
| 292 |
+ comp = 0; |
| 293 |
+ x = 0; |
| 294 |
+ y = 0; |
| 295 |
+ |
| 296 |
+ } else { |
| 297 |
+ |
| 298 |
+ // allocate a buffer for one row of MCUs |
| 299 |
+ bufWidth = ((width + mcuWidth - 1) / mcuWidth) * mcuWidth; |
| 300 |
+ for (i = 0; i < numComps; ++i) { |
| 301 |
+ for (j = 0; j < mcuHeight; ++j) { |
| 302 |
+ rowBuf[i][j] = new uchar[bufWidth]; |
| 303 |
+ } |
| 304 |
+ } |
| 305 |
+ |
| 306 |
+ // initialize counters |
| 307 |
+ comp = 0; |
| 308 |
+ x = 0; |
| 309 |
+ y = 0; |
| 310 |
+ dy = mcuHeight; |
| 311 |
+ |
| 312 |
+ restartMarker = 0xd0; |
| 313 |
+ restart(); |
| 314 |
+ } |
| 315 |
+} |
| 316 |
+ |
| 317 |
+int DCTStream::getChar() |
| 318 |
+{ |
| 319 |
+ int c; |
| 320 |
+ |
| 321 |
+ if (y >= height) { |
| 322 |
+ return EOF; |
| 323 |
+ } |
| 324 |
+ if (progressive || !interleaved) { |
| 325 |
+ c = frameBuf[comp][y * bufWidth + x]; |
| 326 |
+ if (++comp == numComps) { |
| 327 |
+ comp = 0; |
| 328 |
+ if (++x == width) { |
| 329 |
+ x = 0; |
| 330 |
+ ++y; |
| 331 |
+ } |
| 332 |
+ } |
| 333 |
+ } else { |
| 334 |
+ if (dy >= mcuHeight) { |
| 335 |
+ if (!readMCURow()) { |
| 336 |
+ y = height; |
| 337 |
+ return EOF; |
| 338 |
+ } |
| 339 |
+ comp = 0; |
| 340 |
+ x = 0; |
| 341 |
+ dy = 0; |
| 342 |
+ } |
| 343 |
+ c = rowBuf[comp][dy][x]; |
| 344 |
+ if (++comp == numComps) { |
| 345 |
+ comp = 0; |
| 346 |
+ if (++x == width) { |
| 347 |
+ x = 0; |
| 348 |
+ ++y; |
| 349 |
+ ++dy; |
| 350 |
+ if (y == height) { |
| 351 |
+ readTrailer(); |
| 352 |
+ } |
| 353 |
+ } |
| 354 |
+ } |
| 355 |
+ } |
| 356 |
+ return c; |
| 357 |
+} |
| 358 |
+ |
| 359 |
+void DCTStream::restart() |
| 360 |
+{ |
| 361 |
+ int i; |
| 362 |
+ |
| 363 |
+ inputBits = 0; |
| 364 |
+ restartCtr = restartInterval; |
| 365 |
+ for (i = 0; i < numComps; ++i) { |
| 366 |
+ compInfo[i].prevDC = 0; |
| 367 |
+ } |
| 368 |
+ eobRun = 0; |
| 369 |
+} |
| 370 |
+ |
| 371 |
+// Read one row of MCUs from a sequential JPEG stream. |
| 372 |
+bool DCTStream::readMCURow() |
| 373 |
+{ |
| 374 |
+ int data1[64]; |
| 375 |
+ uchar data2[64]; |
| 376 |
+ uchar *p1, *p2; |
| 377 |
+ int pY, pCb, pCr, pR, pG, pB; |
| 378 |
+ int h, v, horiz, vert, hSub, vSub; |
| 379 |
+ int x1, x2, y2, x3, y3, x4, y4, x5, y5, cc, i; |
| 380 |
+ int c; |
| 381 |
+ |
| 382 |
+ for (x1 = 0; x1 < width; x1 += mcuWidth) { |
| 383 |
+ |
| 384 |
+ // deal with restart marker |
| 385 |
+ if (restartInterval > 0 && restartCtr == 0) { |
| 386 |
+ c = readMarker(); |
| 387 |
+ if (c != restartMarker) { |
| 388 |
+ ipeDebug("Bad DCT data: incorrect restart marker"); |
| 389 |
+ return false; |
| 390 |
+ } |
| 391 |
+ if (++restartMarker == 0xd8) |
| 392 |
+ restartMarker = 0xd0; |
| 393 |
+ restart(); |
| 394 |
+ } |
| 395 |
+ |
| 396 |
+ // read one MCU |
| 397 |
+ for (cc = 0; cc < numComps; ++cc) { |
| 398 |
+ h = compInfo[cc].hSample; |
| 399 |
+ v = compInfo[cc].vSample; |
| 400 |
+ horiz = mcuWidth / h; |
| 401 |
+ vert = mcuHeight / v; |
| 402 |
+ hSub = horiz / 8; |
| 403 |
+ vSub = vert / 8; |
| 404 |
+ for (y2 = 0; y2 < mcuHeight; y2 += vert) { |
| 405 |
+ for (x2 = 0; x2 < mcuWidth; x2 += horiz) { |
| 406 |
+ if (!readDataUnit(&dcHuffTables[scanInfo.dcHuffTable[cc]], |
| 407 |
+ &acHuffTables[scanInfo.acHuffTable[cc]], |
| 408 |
+ &compInfo[cc].prevDC, |
| 409 |
+ data1)) { |
| 410 |
+ return false; |
| 411 |
+ } |
| 412 |
+ transformDataUnit(quantTables[compInfo[cc].quantTable], |
| 413 |
+ data1, data2); |
| 414 |
+ if (hSub == 1 && vSub == 1) { |
| 415 |
+ for (y3 = 0, i = 0; y3 < 8; ++y3, i += 8) { |
| 416 |
+ p1 = &rowBuf[cc][y2+y3][x1+x2]; |
| 417 |
+ p1[0] = data2[i]; |
| 418 |
+ p1[1] = data2[i+1]; |
| 419 |
+ p1[2] = data2[i+2]; |
| 420 |
+ p1[3] = data2[i+3]; |
| 421 |
+ p1[4] = data2[i+4]; |
| 422 |
+ p1[5] = data2[i+5]; |
| 423 |
+ p1[6] = data2[i+6]; |
| 424 |
+ p1[7] = data2[i+7]; |
| 425 |
+ } |
| 426 |
+ } else if (hSub == 2 && vSub == 2) { |
| 427 |
+ for (y3 = 0, i = 0; y3 < 16; y3 += 2, i += 8) { |
| 428 |
+ p1 = &rowBuf[cc][y2+y3][x1+x2]; |
| 429 |
+ p2 = &rowBuf[cc][y2+y3+1][x1+x2]; |
| 430 |
+ p1[0] = p1[1] = p2[0] = p2[1] = data2[i]; |
| 431 |
+ p1[2] = p1[3] = p2[2] = p2[3] = data2[i+1]; |
| 432 |
+ p1[4] = p1[5] = p2[4] = p2[5] = data2[i+2]; |
| 433 |
+ p1[6] = p1[7] = p2[6] = p2[7] = data2[i+3]; |
| 434 |
+ p1[8] = p1[9] = p2[8] = p2[9] = data2[i+4]; |
| 435 |
+ p1[10] = p1[11] = p2[10] = p2[11] = data2[i+5]; |
| 436 |
+ p1[12] = p1[13] = p2[12] = p2[13] = data2[i+6]; |
| 437 |
+ p1[14] = p1[15] = p2[14] = p2[15] = data2[i+7]; |
| 438 |
+ } |
| 439 |
+ } else { |
| 440 |
+ i = 0; |
| 441 |
+ for (y3 = 0, y4 = 0; y3 < 8; ++y3, y4 += vSub) { |
| 442 |
+ for (x3 = 0, x4 = 0; x3 < 8; ++x3, x4 += hSub) { |
| 443 |
+ for (y5 = 0; y5 < vSub; ++y5) |
| 444 |
+ for (x5 = 0; x5 < hSub; ++x5) |
| 445 |
+ rowBuf[cc][y2+y4+y5][x1+x2+x4+x5] = data2[i]; |
| 446 |
+ ++i; |
| 447 |
+ } |
| 448 |
+ } |
| 449 |
+ } |
| 450 |
+ } |
| 451 |
+ } |
| 452 |
+ } |
| 453 |
+ --restartCtr; |
| 454 |
+ |
| 455 |
+ // color space conversion |
| 456 |
+ if (colorXform) { |
| 457 |
+ // convert YCbCr to RGB |
| 458 |
+ if (numComps == 3) { |
| 459 |
+ for (y2 = 0; y2 < mcuHeight; ++y2) { |
| 460 |
+ for (x2 = 0; x2 < mcuWidth; ++x2) { |
| 461 |
+ pY = rowBuf[0][y2][x1+x2]; |
| 462 |
+ pCb = rowBuf[1][y2][x1+x2] - 128; |
| 463 |
+ pCr = rowBuf[2][y2][x1+x2] - 128; |
| 464 |
+ pR = ((pY << 16) + dctCrToR * pCr + 32768) >> 16; |
| 465 |
+ rowBuf[0][y2][x1+x2] = dctClip[dctClipOffset + pR]; |
| 466 |
+ pG = ((pY << 16) + dctCbToG * pCb + dctCrToG * pCr + 32768) >> 16; |
| 467 |
+ rowBuf[1][y2][x1+x2] = dctClip[dctClipOffset + pG]; |
| 468 |
+ pB = ((pY << 16) + dctCbToB * pCb + 32768) >> 16; |
| 469 |
+ rowBuf[2][y2][x1+x2] = dctClip[dctClipOffset + pB]; |
| 470 |
+ } |
| 471 |
+ } |
| 472 |
+ // convert YCbCrK to CMYK (K is passed through unchanged) |
| 473 |
+ } else if (numComps == 4) { |
| 474 |
+ for (y2 = 0; y2 < mcuHeight; ++y2) { |
| 475 |
+ for (x2 = 0; x2 < mcuWidth; ++x2) { |
| 476 |
+ pY = rowBuf[0][y2][x1+x2]; |
| 477 |
+ pCb = rowBuf[1][y2][x1+x2] - 128; |
| 478 |
+ pCr = rowBuf[2][y2][x1+x2] - 128; |
| 479 |
+ pR = ((pY << 16) + dctCrToR * pCr + 32768) >> 16; |
| 480 |
+ rowBuf[0][y2][x1+x2] = uchar(255 - dctClip[dctClipOffset + pR]); |
| 481 |
+ pG = ((pY << 16) + dctCbToG * pCb + dctCrToG * pCr + 32768) >> 16; |
| 482 |
+ rowBuf[1][y2][x1+x2] = uchar(255 - dctClip[dctClipOffset + pG]); |
| 483 |
+ pB = ((pY << 16) + dctCbToB * pCb + 32768) >> 16; |
| 484 |
+ rowBuf[2][y2][x1+x2] = uchar(255 - dctClip[dctClipOffset + pB]); |
| 485 |
+ } |
| 486 |
+ } |
| 487 |
+ } |
| 488 |
+ } |
| 489 |
+ } |
| 490 |
+ return true; |
| 491 |
+} |
| 492 |
+ |
| 493 |
+// Read one scan from a progressive or non-interleaved JPEG stream. |
| 494 |
+void DCTStream::readScan() |
| 495 |
+{ |
| 496 |
+ int data[64]; |
| 497 |
+ int x1, y1, dy1, x2, y2, y3, cc, i; |
| 498 |
+ int h, v, horiz, vert, vSub; |
| 499 |
+ int *p1; |
| 500 |
+ int c; |
| 501 |
+ |
| 502 |
+ if (scanInfo.numComps == 1) { |
| 503 |
+ for (cc = 0; cc < numComps; ++cc) { |
| 504 |
+ if (scanInfo.comp[cc]) { |
| 505 |
+ break; |
| 506 |
+ } |
| 507 |
+ } |
| 508 |
+ dy1 = mcuHeight / compInfo[cc].vSample; |
| 509 |
+ } else { |
| 510 |
+ dy1 = mcuHeight; |
| 511 |
+ } |
| 512 |
+ |
| 513 |
+ for (y1 = 0; y1 < bufHeight; y1 += dy1) { |
| 514 |
+ for (x1 = 0; x1 < bufWidth; x1 += mcuWidth) { |
| 515 |
+ |
| 516 |
+ // deal with restart marker |
| 517 |
+ if (restartInterval > 0 && restartCtr == 0) { |
| 518 |
+ c = readMarker(); |
| 519 |
+ if (c != restartMarker) { |
| 520 |
+ ipeDebug("Bad DCT data: incorrect restart marker"); |
| 521 |
+ return; |
| 522 |
+ } |
| 523 |
+ if (++restartMarker == 0xd8) { |
| 524 |
+ restartMarker = 0xd0; |
| 525 |
+ } |
| 526 |
+ restart(); |
| 527 |
+ } |
| 528 |
+ |
| 529 |
+ // read one MCU |
| 530 |
+ for (cc = 0; cc < numComps; ++cc) { |
| 531 |
+ if (!scanInfo.comp[cc]) { |
| 532 |
+ continue; |
| 533 |
+ } |
| 534 |
+ |
| 535 |
+ h = compInfo[cc].hSample; |
| 536 |
+ v = compInfo[cc].vSample; |
| 537 |
+ horiz = mcuWidth / h; |
| 538 |
+ vert = mcuHeight / v; |
| 539 |
+ // hSub = horiz / 8; |
| 540 |
+ vSub = vert / 8; |
| 541 |
+ for (y2 = 0; y2 < dy1; y2 += vert) { |
| 542 |
+ for (x2 = 0; x2 < mcuWidth; x2 += horiz) { |
| 543 |
+ |
| 544 |
+ // pull out the current values |
| 545 |
+ p1 = &frameBuf[cc][(y1+y2) * bufWidth + (x1+x2)]; |
| 546 |
+ for (y3 = 0, i = 0; y3 < 8; ++y3, i += 8) { |
| 547 |
+ data[i] = p1[0]; |
| 548 |
+ data[i+1] = p1[1]; |
| 549 |
+ data[i+2] = p1[2]; |
| 550 |
+ data[i+3] = p1[3]; |
| 551 |
+ data[i+4] = p1[4]; |
| 552 |
+ data[i+5] = p1[5]; |
| 553 |
+ data[i+6] = p1[6]; |
| 554 |
+ data[i+7] = p1[7]; |
| 555 |
+ p1 += bufWidth * vSub; |
| 556 |
+ } |
| 557 |
+ |
| 558 |
+ // read one data unit |
| 559 |
+ if (progressive) { |
| 560 |
+ if (!readProgressiveDataUnit( |
| 561 |
+ &dcHuffTables[scanInfo.dcHuffTable[cc]], |
| 562 |
+ &acHuffTables[scanInfo.acHuffTable[cc]], |
| 563 |
+ &compInfo[cc].prevDC, |
| 564 |
+ data)) { |
| 565 |
+ return; |
| 566 |
+ } |
| 567 |
+ } else { |
| 568 |
+ if (!readDataUnit(&dcHuffTables[scanInfo.dcHuffTable[cc]], |
| 569 |
+ &acHuffTables[scanInfo.acHuffTable[cc]], |
| 570 |
+ &compInfo[cc].prevDC, |
| 571 |
+ data)) { |
| 572 |
+ return; |
| 573 |
+ } |
| 574 |
+ } |
| 575 |
+ |
| 576 |
+ // add the data unit into frameBuf |
| 577 |
+ p1 = &frameBuf[cc][(y1+y2) * bufWidth + (x1+x2)]; |
| 578 |
+ for (y3 = 0, i = 0; y3 < 8; ++y3, i += 8) { |
| 579 |
+ p1[0] = data[i]; |
| 580 |
+ p1[1] = data[i+1]; |
| 581 |
+ p1[2] = data[i+2]; |
| 582 |
+ p1[3] = data[i+3]; |
| 583 |
+ p1[4] = data[i+4]; |
| 584 |
+ p1[5] = data[i+5]; |
| 585 |
+ p1[6] = data[i+6]; |
| 586 |
+ p1[7] = data[i+7]; |
| 587 |
+ p1 += bufWidth * vSub; |
| 588 |
+ } |
| 589 |
+ } |
| 590 |
+ } |
| 591 |
+ } |
| 592 |
+ --restartCtr; |
| 593 |
+ } |
| 594 |
+ } |
| 595 |
+} |
| 596 |
+ |
| 597 |
+// Read one data unit from a sequential JPEG stream. |
| 598 |
+bool DCTStream::readDataUnit(DCTHuffTable *dcHuffTable, |
| 599 |
+ DCTHuffTable *acHuffTable, |
| 600 |
+ int *prevDC, int data[64]) |
| 601 |
+{ |
| 602 |
+ int run, size, amp; |
| 603 |
+ int c; |
| 604 |
+ int i, j; |
| 605 |
+ |
| 606 |
+ if ((size = readHuffSym(dcHuffTable)) == 9999) { |
| 607 |
+ return false; |
| 608 |
+ } |
| 609 |
+ if (size > 0) { |
| 610 |
+ if ((amp = readAmp(size)) == 9999) { |
| 611 |
+ return false; |
| 612 |
+ } |
| 613 |
+ } else { |
| 614 |
+ amp = 0; |
| 615 |
+ } |
| 616 |
+ data[0] = *prevDC += amp; |
| 617 |
+ for (i = 1; i < 64; ++i) { |
| 618 |
+ data[i] = 0; |
| 619 |
+ } |
| 620 |
+ i = 1; |
| 621 |
+ while (i < 64) { |
| 622 |
+ run = 0; |
| 623 |
+ while ((c = readHuffSym(acHuffTable)) == 0xf0 && run < 0x30) { |
| 624 |
+ run += 0x10; |
| 625 |
+ } |
| 626 |
+ if (c == 9999) { |
| 627 |
+ return false; |
| 628 |
+ } |
| 629 |
+ if (c == 0x00) { |
| 630 |
+ break; |
| 631 |
+ } else { |
| 632 |
+ run += (c >> 4) & 0x0f; |
| 633 |
+ size = c & 0x0f; |
| 634 |
+ amp = readAmp(size); |
| 635 |
+ if (amp == 9999) { |
| 636 |
+ return false; |
| 637 |
+ } |
| 638 |
+ i += run; |
| 639 |
+ j = dctZigZag[i++]; |
| 640 |
+ data[j] = amp; |
| 641 |
+ } |
| 642 |
+ } |
| 643 |
+ return true; |
| 644 |
+} |
| 645 |
+ |
| 646 |
+// Read one data unit from a sequential JPEG stream. |
| 647 |
+bool DCTStream::readProgressiveDataUnit(DCTHuffTable *dcHuffTable, |
| 648 |
+ DCTHuffTable *acHuffTable, |
| 649 |
+ int *prevDC, int data[64]) |
| 650 |
+{ |
| 651 |
+ int run, size, amp, bit, c; |
| 652 |
+ int i, j, k; |
| 653 |
+ |
| 654 |
+ // get the DC coefficient |
| 655 |
+ i = scanInfo.firstCoeff; |
| 656 |
+ if (i == 0) { |
| 657 |
+ if (scanInfo.ah == 0) { |
| 658 |
+ if ((size = readHuffSym(dcHuffTable)) == 9999) { |
| 659 |
+ return false; |
| 660 |
+ } |
| 661 |
+ if (size > 0) { |
| 662 |
+ if ((amp = readAmp(size)) == 9999) { |
| 663 |
+ return false; |
| 664 |
+ } |
| 665 |
+ } else { |
| 666 |
+ amp = 0; |
| 667 |
+ } |
| 668 |
+ data[0] += (*prevDC += amp) << scanInfo.al; |
| 669 |
+ } else { |
| 670 |
+ if ((bit = readBit()) == 9999) { |
| 671 |
+ return false; |
| 672 |
+ } |
| 673 |
+ data[0] += bit << scanInfo.al; |
| 674 |
+ } |
| 675 |
+ ++i; |
| 676 |
+ } |
| 677 |
+ if (scanInfo.lastCoeff == 0) { |
| 678 |
+ return true; |
| 679 |
+ } |
| 680 |
+ |
| 681 |
+ // check for an EOB run |
| 682 |
+ if (eobRun > 0) { |
| 683 |
+ while (i <= scanInfo.lastCoeff) { |
| 684 |
+ j = dctZigZag[i++]; |
| 685 |
+ if (data[j] != 0) { |
| 686 |
+ if ((bit = readBit()) == EOF) { |
| 687 |
+ return false; |
| 688 |
+ } |
| 689 |
+ if (bit) { |
| 690 |
+ data[j] += 1 << scanInfo.al; |
| 691 |
+ } |
| 692 |
+ } |
| 693 |
+ } |
| 694 |
+ --eobRun; |
| 695 |
+ return true; |
| 696 |
+ } |
| 697 |
+ |
| 698 |
+ // read the AC coefficients |
| 699 |
+ while (i <= scanInfo.lastCoeff) { |
| 700 |
+ if ((c = readHuffSym(acHuffTable)) == 9999) { |
| 701 |
+ return false; |
| 702 |
+ } |
| 703 |
+ |
| 704 |
+ // ZRL |
| 705 |
+ if (c == 0xf0) { |
| 706 |
+ k = 0; |
| 707 |
+ while (k < 16) { |
| 708 |
+ j = dctZigZag[i++]; |
| 709 |
+ if (data[j] == 0) { |
| 710 |
+ ++k; |
| 711 |
+ } else { |
| 712 |
+ if ((bit = readBit()) == EOF) { |
| 713 |
+ return false; |
| 714 |
+ } |
| 715 |
+ if (bit) { |
| 716 |
+ data[j] += 1 << scanInfo.al; |
| 717 |
+ } |
| 718 |
+ } |
| 719 |
+ } |
| 720 |
+ |
| 721 |
+ // EOB run |
| 722 |
+ } else if ((c & 0x0f) == 0x00) { |
| 723 |
+ j = c >> 4; |
| 724 |
+ eobRun = 0; |
| 725 |
+ for (k = 0; k < j; ++k) { |
| 726 |
+ if ((bit = readBit()) == EOF) { |
| 727 |
+ return 9999; |
| 728 |
+ } |
| 729 |
+ eobRun = (eobRun << 1) | bit; |
| 730 |
+ } |
| 731 |
+ eobRun += 1 << j; |
| 732 |
+ while (i <= scanInfo.lastCoeff) { |
| 733 |
+ j = dctZigZag[i++]; |
| 734 |
+ if (data[j] != 0) { |
| 735 |
+ if ((bit = readBit()) == EOF) { |
| 736 |
+ return false; |
| 737 |
+ } |
| 738 |
+ if (bit) { |
| 739 |
+ data[j] += 1 << scanInfo.al; |
| 740 |
+ } |
| 741 |
+ } |
| 742 |
+ } |
| 743 |
+ --eobRun; |
| 744 |
+ break; |
| 745 |
+ |
| 746 |
+ // zero run and one AC coefficient |
| 747 |
+ } else { |
| 748 |
+ run = (c >> 4) & 0x0f; |
| 749 |
+ size = c & 0x0f; |
| 750 |
+ if ((amp = readAmp(size)) == 9999) { |
| 751 |
+ return false; |
| 752 |
+ } |
| 753 |
+ k = 0; |
| 754 |
+ do { |
| 755 |
+ j = dctZigZag[i++]; |
| 756 |
+ while (data[j] != 0) { |
| 757 |
+ if ((bit = readBit()) == EOF) { |
| 758 |
+ return false; |
| 759 |
+ } |
| 760 |
+ if (bit) { |
| 761 |
+ data[j] += 1 << scanInfo.al; |
| 762 |
+ } |
| 763 |
+ j = dctZigZag[i++]; |
| 764 |
+ } |
| 765 |
+ ++k; |
| 766 |
+ } while (k <= run); |
| 767 |
+ data[j] = amp << scanInfo.al; |
| 768 |
+ } |
| 769 |
+ } |
| 770 |
+ |
| 771 |
+ return true; |
| 772 |
+} |
| 773 |
+ |
| 774 |
+// Decode a progressive JPEG image. |
| 775 |
+void DCTStream::decodeImage() |
| 776 |
+{ |
| 777 |
+ int dataIn[64]; |
| 778 |
+ uchar dataOut[64]; |
| 779 |
+ uchar *quantTable; |
| 780 |
+ int pY, pCb, pCr, pR, pG, pB; |
| 781 |
+ int x1, y1, x2, y2, x3, y3, x4, y4, x5, y5, cc, i; |
| 782 |
+ int h, v, horiz, vert, hSub, vSub; |
| 783 |
+ int *p0, *p1, *p2; |
| 784 |
+ |
| 785 |
+ for (y1 = 0; y1 < bufHeight; y1 += mcuHeight) { |
| 786 |
+ for (x1 = 0; x1 < bufWidth; x1 += mcuWidth) { |
| 787 |
+ for (cc = 0; cc < numComps; ++cc) { |
| 788 |
+ quantTable = quantTables[compInfo[cc].quantTable]; |
| 789 |
+ h = compInfo[cc].hSample; |
| 790 |
+ v = compInfo[cc].vSample; |
| 791 |
+ horiz = mcuWidth / h; |
| 792 |
+ vert = mcuHeight / v; |
| 793 |
+ hSub = horiz / 8; |
| 794 |
+ vSub = vert / 8; |
| 795 |
+ for (y2 = 0; y2 < mcuHeight; y2 += vert) { |
| 796 |
+ for (x2 = 0; x2 < mcuWidth; x2 += horiz) { |
| 797 |
+ |
| 798 |
+ // pull out the coded data unit |
| 799 |
+ p1 = &frameBuf[cc][(y1+y2) * bufWidth + (x1+x2)]; |
| 800 |
+ for (y3 = 0, i = 0; y3 < 8; ++y3, i += 8) { |
| 801 |
+ dataIn[i] = p1[0]; |
| 802 |
+ dataIn[i+1] = p1[1]; |
| 803 |
+ dataIn[i+2] = p1[2]; |
| 804 |
+ dataIn[i+3] = p1[3]; |
| 805 |
+ dataIn[i+4] = p1[4]; |
| 806 |
+ dataIn[i+5] = p1[5]; |
| 807 |
+ dataIn[i+6] = p1[6]; |
| 808 |
+ dataIn[i+7] = p1[7]; |
| 809 |
+ p1 += bufWidth * vSub; |
| 810 |
+ } |
| 811 |
+ |
| 812 |
+ // transform |
| 813 |
+ transformDataUnit(quantTable, dataIn, dataOut); |
| 814 |
+ |
| 815 |
+ // store back into frameBuf, doing replication for |
| 816 |
+ // subsampled components |
| 817 |
+ p1 = &frameBuf[cc][(y1+y2) * bufWidth + (x1+x2)]; |
| 818 |
+ if (hSub == 1 && vSub == 1) { |
| 819 |
+ for (y3 = 0, i = 0; y3 < 8; ++y3, i += 8) { |
| 820 |
+ p1[0] = dataOut[i] & 0xff; |
| 821 |
+ p1[1] = dataOut[i+1] & 0xff; |
| 822 |
+ p1[2] = dataOut[i+2] & 0xff; |
| 823 |
+ p1[3] = dataOut[i+3] & 0xff; |
| 824 |
+ p1[4] = dataOut[i+4] & 0xff; |
| 825 |
+ p1[5] = dataOut[i+5] & 0xff; |
| 826 |
+ p1[6] = dataOut[i+6] & 0xff; |
| 827 |
+ p1[7] = dataOut[i+7] & 0xff; |
| 828 |
+ p1 += bufWidth; |
| 829 |
+ } |
| 830 |
+ } else if (hSub == 2 && vSub == 2) { |
| 831 |
+ p2 = p1 + bufWidth; |
| 832 |
+ for (y3 = 0, i = 0; y3 < 16; y3 += 2, i += 8) { |
| 833 |
+ p1[0] = p1[1] = p2[0] = p2[1] = dataOut[i] & 0xff; |
| 834 |
+ p1[2] = p1[3] = p2[2] = p2[3] = dataOut[i+1] & 0xff; |
| 835 |
+ p1[4] = p1[5] = p2[4] = p2[5] = dataOut[i+2] & 0xff; |
| 836 |
+ p1[6] = p1[7] = p2[6] = p2[7] = dataOut[i+3] & 0xff; |
| 837 |
+ p1[8] = p1[9] = p2[8] = p2[9] = dataOut[i+4] & 0xff; |
| 838 |
+ p1[10] = p1[11] = p2[10] = p2[11] = dataOut[i+5] & 0xff; |
| 839 |
+ p1[12] = p1[13] = p2[12] = p2[13] = dataOut[i+6] & 0xff; |
| 840 |
+ p1[14] = p1[15] = p2[14] = p2[15] = dataOut[i+7] & 0xff; |
| 841 |
+ p1 += bufWidth * 2; |
| 842 |
+ p2 += bufWidth * 2; |
| 843 |
+ } |
| 844 |
+ } else { |
| 845 |
+ i = 0; |
| 846 |
+ for (y3 = 0, y4 = 0; y3 < 8; ++y3, y4 += vSub) { |
| 847 |
+ for (x3 = 0, x4 = 0; x3 < 8; ++x3, x4 += hSub) { |
| 848 |
+ p2 = p1 + x4; |
| 849 |
+ for (y5 = 0; y5 < vSub; ++y5) { |
| 850 |
+ for (x5 = 0; x5 < hSub; ++x5) { |
| 851 |
+ p2[x5] = dataOut[i] & 0xff; |
| 852 |
+ } |
| 853 |
+ p2 += bufWidth; |
| 854 |
+ } |
| 855 |
+ ++i; |
| 856 |
+ } |
| 857 |
+ p1 += bufWidth * vSub; |
| 858 |
+ } |
| 859 |
+ } |
| 860 |
+ } |
| 861 |
+ } |
| 862 |
+ } |
| 863 |
+ |
| 864 |
+ // color space conversion |
| 865 |
+ if (colorXform) { |
| 866 |
+ // convert YCbCr to RGB |
| 867 |
+ if (numComps == 3) { |
| 868 |
+ for (y2 = 0; y2 < mcuHeight; ++y2) { |
| 869 |
+ p0 = &frameBuf[0][(y1+y2) * bufWidth + x1]; |
| 870 |
+ p1 = &frameBuf[1][(y1+y2) * bufWidth + x1]; |
| 871 |
+ p2 = &frameBuf[2][(y1+y2) * bufWidth + x1]; |
| 872 |
+ for (x2 = 0; x2 < mcuWidth; ++x2) { |
| 873 |
+ pY = *p0; |
| 874 |
+ pCb = *p1 - 128; |
| 875 |
+ pCr = *p2 - 128; |
| 876 |
+ pR = ((pY << 16) + dctCrToR * pCr + 32768) >> 16; |
| 877 |
+ *p0++ = dctClip[dctClipOffset + pR]; |
| 878 |
+ pG = ((pY << 16) + dctCbToG * pCb + dctCrToG * pCr + |
| 879 |
+ 32768) >> 16; |
| 880 |
+ *p1++ = dctClip[dctClipOffset + pG]; |
| 881 |
+ pB = ((pY << 16) + dctCbToB * pCb + 32768) >> 16; |
| 882 |
+ *p2++ = dctClip[dctClipOffset + pB]; |
| 883 |
+ } |
| 884 |
+ } |
| 885 |
+ // convert YCbCrK to CMYK (K is passed through unchanged) |
| 886 |
+ } else if (numComps == 4) { |
| 887 |
+ for (y2 = 0; y2 < mcuHeight; ++y2) { |
| 888 |
+ p0 = &frameBuf[0][(y1+y2) * bufWidth + x1]; |
| 889 |
+ p1 = &frameBuf[1][(y1+y2) * bufWidth + x1]; |
| 890 |
+ p2 = &frameBuf[2][(y1+y2) * bufWidth + x1]; |
| 891 |
+ for (x2 = 0; x2 < mcuWidth; ++x2) { |
| 892 |
+ pY = *p0; |
| 893 |
+ pCb = *p1 - 128; |
| 894 |
+ pCr = *p2 - 128; |
| 895 |
+ pR = ((pY << 16) + dctCrToR * pCr + 32768) >> 16; |
| 896 |
+ *p0++ = 255 - dctClip[dctClipOffset + pR]; |
| 897 |
+ pG = ((pY << 16) + dctCbToG * pCb + dctCrToG * pCr + |
| 898 |
+ 32768) >> 16; |
| 899 |
+ *p1++ = 255 - dctClip[dctClipOffset + pG]; |
| 900 |
+ pB = ((pY << 16) + dctCbToB * pCb + 32768) >> 16; |
| 901 |
+ *p2++ = 255 - dctClip[dctClipOffset + pB]; |
| 902 |
+ } |
| 903 |
+ } |
| 904 |
+ } |
| 905 |
+ } |
| 906 |
+ } |
| 907 |
+ } |
| 908 |
+} |
| 909 |
+ |
| 910 |
+// Transform one data unit -- this performs the dequantization and |
| 911 |
+// IDCT steps. This IDCT algorithm is taken from: |
| 912 |
+// Christoph Loeffler, Adriaan Ligtenberg, George S. Moschytz, |
| 913 |
+// "Practical Fast 1-D DCT Algorithms with 11 Multiplications", |
| 914 |
+// IEEE Intl. Conf. on Acoustics, Speech & Signal Processing, 1989, |
| 915 |
+// 988-991. |
| 916 |
+// The stage numbers mentioned in the comments refer to Figure 1 in this |
| 917 |
+// paper. |
| 918 |
+void DCTStream::transformDataUnit(uchar *quantTable, |
| 919 |
+ int dataIn[64], uchar dataOut[64]) |
| 920 |
+{ |
| 921 |
+ int v0, v1, v2, v3, v4, v5, v6, v7, t; |
| 922 |
+ int *p; |
| 923 |
+ int i; |
| 924 |
+ |
| 925 |
+ // dequant |
| 926 |
+ for (i = 0; i < 64; ++i) { |
| 927 |
+ dataIn[i] *= quantTable[i]; |
| 928 |
+ } |
| 929 |
+ |
| 930 |
+ // inverse DCT on rows |
| 931 |
+ for (i = 0; i < 64; i += 8) { |
| 932 |
+ p = dataIn + i; |
| 933 |
+ |
| 934 |
+ // check for all-zero AC coefficients |
| 935 |
+ if (p[1] == 0 && p[2] == 0 && p[3] == 0 && |
| 936 |
+ p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] == 0) { |
| 937 |
+ t = (dctSqrt2 * p[0] + 512) >> 10; |
| 938 |
+ p[0] = t; |
| 939 |
+ p[1] = t; |
| 940 |
+ p[2] = t; |
| 941 |
+ p[3] = t; |
| 942 |
+ p[4] = t; |
| 943 |
+ p[5] = t; |
| 944 |
+ p[6] = t; |
| 945 |
+ p[7] = t; |
| 946 |
+ continue; |
| 947 |
+ } |
| 948 |
+ |
| 949 |
+ // stage 4 |
| 950 |
+ v0 = (dctSqrt2 * p[0] + 128) >> 8; |
| 951 |
+ v1 = (dctSqrt2 * p[4] + 128) >> 8; |
| 952 |
+ v2 = p[2]; |
| 953 |
+ v3 = p[6]; |
| 954 |
+ v4 = (dctSqrt1d2 * (p[1] - p[7]) + 128) >> 8; |
| 955 |
+ v7 = (dctSqrt1d2 * (p[1] + p[7]) + 128) >> 8; |
| 956 |
+ v5 = p[3] << 4; |
| 957 |
+ v6 = p[5] << 4; |
| 958 |
+ |
| 959 |
+ // stage 3 |
| 960 |
+ t = (v0 - v1+ 1) >> 1; |
| 961 |
+ v0 = (v0 + v1 + 1) >> 1; |
| 962 |
+ v1 = t; |
| 963 |
+ t = (v2 * dctSin6 + v3 * dctCos6 + 128) >> 8; |
| 964 |
+ v2 = (v2 * dctCos6 - v3 * dctSin6 + 128) >> 8; |
| 965 |
+ v3 = t; |
| 966 |
+ t = (v4 - v6 + 1) >> 1; |
| 967 |
+ v4 = (v4 + v6 + 1) >> 1; |
| 968 |
+ v6 = t; |
| 969 |
+ t = (v7 + v5 + 1) >> 1; |
| 970 |
+ v5 = (v7 - v5 + 1) >> 1; |
| 971 |
+ v7 = t; |
| 972 |
+ |
| 973 |
+ // stage 2 |
| 974 |
+ t = (v0 - v3 + 1) >> 1; |
| 975 |
+ v0 = (v0 + v3 + 1) >> 1; |
| 976 |
+ v3 = t; |
| 977 |
+ t = (v1 - v2 + 1) >> 1; |
| 978 |
+ v1 = (v1 + v2 + 1) >> 1; |
| 979 |
+ v2 = t; |
| 980 |
+ t = (v4 * dctSin3 + v7 * dctCos3 + 2048) >> 12; |
| 981 |
+ v4 = (v4 * dctCos3 - v7 * dctSin3 + 2048) >> 12; |
| 982 |
+ v7 = t; |
| 983 |
+ t = (v5 * dctSin1 + v6 * dctCos1 + 2048) >> 12; |
| 984 |
+ v5 = (v5 * dctCos1 - v6 * dctSin1 + 2048) >> 12; |
| 985 |
+ v6 = t; |
| 986 |
+ |
| 987 |
+ // stage 1 |
| 988 |
+ p[0] = v0 + v7; |
| 989 |
+ p[7] = v0 - v7; |
| 990 |
+ p[1] = v1 + v6; |
| 991 |
+ p[6] = v1 - v6; |
| 992 |
+ p[2] = v2 + v5; |
| 993 |
+ p[5] = v2 - v5; |
| 994 |
+ p[3] = v3 + v4; |
| 995 |
+ p[4] = v3 - v4; |
| 996 |
+ } |
| 997 |
+ |
| 998 |
+ // inverse DCT on columns |
| 999 |
+ for (i = 0; i < 8; ++i) { |
| 1000 |
+ p = dataIn + i; |
| 1001 |
+ |
| 1002 |
+ // check for all-zero AC coefficients |
| 1003 |
+ if (p[1*8] == 0 && p[2*8] == 0 && p[3*8] == 0 && |
| 1004 |
+ p[4*8] == 0 && p[5*8] == 0 && p[6*8] == 0 && p[7*8] == 0) { |
| 1005 |
+ t = (dctSqrt2 * dataIn[i+0] + 8192) >> 14; |
| 1006 |
+ p[0*8] = t; |
| 1007 |
+ p[1*8] = t; |
| 1008 |
+ p[2*8] = t; |
| 1009 |
+ p[3*8] = t; |
| 1010 |
+ p[4*8] = t; |
| 1011 |
+ p[5*8] = t; |
| 1012 |
+ p[6*8] = t; |
| 1013 |
+ p[7*8] = t; |
| 1014 |
+ continue; |
| 1015 |
+ } |
| 1016 |
+ |
| 1017 |
+ // stage 4 |
| 1018 |
+ v0 = (dctSqrt2 * p[0*8] + 2048) >> 12; |
| 1019 |
+ v1 = (dctSqrt2 * p[4*8] + 2048) >> 12; |
| 1020 |
+ v2 = p[2*8]; |
| 1021 |
+ v3 = p[6*8]; |
| 1022 |
+ v4 = (dctSqrt1d2 * (p[1*8] - p[7*8]) + 2048) >> 12; |
| 1023 |
+ v7 = (dctSqrt1d2 * (p[1*8] + p[7*8]) + 2048) >> 12; |
| 1024 |
+ v5 = p[3*8]; |
| 1025 |
+ v6 = p[5*8]; |
| 1026 |
+ |
| 1027 |
+ // stage 3 |
| 1028 |
+ t = (v0 - v1 + 1) >> 1; |
| 1029 |
+ v0 = (v0 + v1 + 1) >> 1; |
| 1030 |
+ v1 = t; |
| 1031 |
+ t = (v2 * dctSin6 + v3 * dctCos6 + 2048) >> 12; |
| 1032 |
+ v2 = (v2 * dctCos6 - v3 * dctSin6 + 2048) >> 12; |
| 1033 |
+ v3 = t; |
| 1034 |
+ t = (v4 - v6 + 1) >> 1; |
| 1035 |
+ v4 = (v4 + v6 + 1) >> 1; |
| 1036 |
+ v6 = t; |
| 1037 |
+ t = (v7 + v5 + 1) >> 1; |
| 1038 |
+ v5 = (v7 - v5 + 1) >> 1; |
| 1039 |
+ v7 = t; |
| 1040 |
+ |
| 1041 |
+ // stage 2 |
| 1042 |
+ t = (v0 - v3 + 1) >> 1; |
| 1043 |
+ v0 = (v0 + v3 + 1) >> 1; |
| 1044 |
+ v3 = t; |
| 1045 |
+ t = (v1 - v2 + 1) >> 1; |
| 1046 |
+ v1 = (v1 + v2 + 1) >> 1; |
| 1047 |
+ v2 = t; |
| 1048 |
+ t = (v4 * dctSin3 + v7 * dctCos3 + 2048) >> 12; |
| 1049 |
+ v4 = (v4 * dctCos3 - v7 * dctSin3 + 2048) >> 12; |
| 1050 |
+ v7 = t; |
| 1051 |
+ t = (v5 * dctSin1 + v6 * dctCos1 + 2048) >> 12; |
| 1052 |
+ v5 = (v5 * dctCos1 - v6 * dctSin1 + 2048) >> 12; |
| 1053 |
+ v6 = t; |
| 1054 |
+ |
| 1055 |
+ // stage 1 |
| 1056 |
+ p[0*8] = v0 + v7; |
| 1057 |
+ p[7*8] = v0 - v7; |
| 1058 |
+ p[1*8] = v1 + v6; |
| 1059 |
+ p[6*8] = v1 - v6; |
| 1060 |
+ p[2*8] = v2 + v5; |
| 1061 |
+ p[5*8] = v2 - v5; |
| 1062 |
+ p[3*8] = v3 + v4; |
| 1063 |
+ p[4*8] = v3 - v4; |
| 1064 |
+ } |
| 1065 |
+ |
| 1066 |
+ // convert to 8-bit integers |
| 1067 |
+ for (i = 0; i < 64; ++i) { |
| 1068 |
+ dataOut[i] = dctClip[dctClipOffset + 128 + ((dataIn[i] + 8) >> 4)]; |
| 1069 |
+ } |
| 1070 |
+} |
| 1071 |
+ |
| 1072 |
+int DCTStream::readHuffSym(DCTHuffTable *table) |
| 1073 |
+{ |
| 1074 |
+ ushort code; |
| 1075 |
+ int bit; |
| 1076 |
+ int codeBits; |
| 1077 |
+ |
| 1078 |
+ code = 0; |
| 1079 |
+ codeBits = 0; |
| 1080 |
+ do { |
| 1081 |
+ // add a bit to the code |
| 1082 |
+ if ((bit = readBit()) == EOF) |
| 1083 |
+ return 9999; |
| 1084 |
+ code = ushort((code << 1) + bit); |
| 1085 |
+ ++codeBits; |
| 1086 |
+ |
| 1087 |
+ // look up code |
| 1088 |
+ if (code - table->firstCode[codeBits] < table->numCodes[codeBits]) { |
| 1089 |
+ code -= table->firstCode[codeBits]; |
| 1090 |
+ return table->sym[table->firstSym[codeBits] + code]; |
| 1091 |
+ } |
| 1092 |
+ } while (codeBits < 16); |
| 1093 |
+ |
| 1094 |
+ ipeDebug("Bad Huffman code in DCT stream"); |
| 1095 |
+ return 9999; |
| 1096 |
+} |
| 1097 |
+ |
| 1098 |
+int DCTStream::readAmp(int size) |
| 1099 |
+{ |
| 1100 |
+ int amp, bit; |
| 1101 |
+ int bits; |
| 1102 |
+ |
| 1103 |
+ amp = 0; |
| 1104 |
+ for (bits = 0; bits < size; ++bits) { |
| 1105 |
+ if ((bit = readBit()) == EOF) |
| 1106 |
+ return 9999; |
| 1107 |
+ amp = (amp << 1) + bit; |
| 1108 |
+ } |
| 1109 |
+ if (amp < (1 << (size - 1))) |
| 1110 |
+ amp -= (1 << size) - 1; |
| 1111 |
+ return amp; |
| 1112 |
+} |
| 1113 |
+ |
| 1114 |
+int DCTStream::readBit() |
| 1115 |
+{ |
| 1116 |
+ int bit; |
| 1117 |
+ int c, c2; |
| 1118 |
+ |
| 1119 |
+ if (inputBits == 0) { |
| 1120 |
+ if ((c = iSource.getChar()) == EOF) |
| 1121 |
+ return EOF; |
| 1122 |
+ if (c == 0xff) { |
| 1123 |
+ do { |
| 1124 |
+ c2 = iSource.getChar(); |
| 1125 |
+ } while (c2 == 0xff); |
| 1126 |
+ if (c2 != 0x00) { |
| 1127 |
+ ipeDebug("Bad DCT data: missing 00 after ff"); |
| 1128 |
+ return EOF; |
| 1129 |
+ } |
| 1130 |
+ } |
| 1131 |
+ inputBuf = c; |
| 1132 |
+ inputBits = 8; |
| 1133 |
+ } |
| 1134 |
+ bit = (inputBuf >> (inputBits - 1)) & 1; |
| 1135 |
+ --inputBits; |
| 1136 |
+ return bit; |
| 1137 |
+} |
| 1138 |
+ |
| 1139 |
+bool DCTStream::readHeader() |
| 1140 |
+{ |
| 1141 |
+ bool doScan; |
| 1142 |
+ int n; |
| 1143 |
+ int c; |
| 1144 |
+ int i; |
| 1145 |
+ |
| 1146 |
+ // read headers |
| 1147 |
+ doScan = false; |
| 1148 |
+ while (!doScan) { |
| 1149 |
+ c = readMarker(); |
| 1150 |
+ switch (c) { |
| 1151 |
+ case 0xc0: // SOF0 |
| 1152 |
+ if (!readBaselineSOF()) { |
| 1153 |
+ return false; |
| 1154 |
+ } |
| 1155 |
+ break; |
| 1156 |
+ case 0xc2: // SOF2 |
| 1157 |
+ if (!readProgressiveSOF()) { |
| 1158 |
+ return false; |
| 1159 |
+ } |
| 1160 |
+ break; |
| 1161 |
+ case 0xc4: // DHT |
| 1162 |
+ if (!readHuffmanTables()) { |
| 1163 |
+ return false; |
| 1164 |
+ } |
| 1165 |
+ break; |
| 1166 |
+ case 0xd8: // SOI |
| 1167 |
+ break; |
| 1168 |
+ case 0xd9: // EOI |
| 1169 |
+ return false; |
| 1170 |
+ case 0xda: // SOS |
| 1171 |
+ if (!readScanInfo()) { |
| 1172 |
+ return false; |
| 1173 |
+ } |
| 1174 |
+ doScan = true; |
| 1175 |
+ break; |
| 1176 |
+ case 0xdb: // DQT |
| 1177 |
+ if (!readQuantTables()) { |
| 1178 |
+ return false; |
| 1179 |
+ } |
| 1180 |
+ break; |
| 1181 |
+ case 0xdd: // DRI |
| 1182 |
+ if (!readRestartInterval()) { |
| 1183 |
+ return false; |
| 1184 |
+ } |
| 1185 |
+ break; |
| 1186 |
+ case 0xee: // APP14 |
| 1187 |
+ if (!readAdobeMarker()) { |
| 1188 |
+ return false; |
| 1189 |
+ } |
| 1190 |
+ break; |
| 1191 |
+ case EOF: |
| 1192 |
+ ipeDebug("Bad DCT header"); |
| 1193 |
+ return false; |
| 1194 |
+ default: |
| 1195 |
+ // skip APPn / COM / etc. |
| 1196 |
+ if (c >= 0xe0) { |
| 1197 |
+ n = read16() - 2; |
| 1198 |
+ for (i = 0; i < n; ++i) { |
| 1199 |
+ iSource.getChar(); |
| 1200 |
+ } |
| 1201 |
+ } else { |
| 1202 |
+ ipeDebug("Unknown DCT marker <%02x>", c); |
| 1203 |
+ return false; |
| 1204 |
+ } |
| 1205 |
+ break; |
| 1206 |
+ } |
| 1207 |
+ } |
| 1208 |
+ |
| 1209 |
+ return true; |
| 1210 |
+} |
| 1211 |
+ |
| 1212 |
+bool DCTStream::readBaselineSOF() |
| 1213 |
+{ |
| 1214 |
+ (void) read16(); // length |
| 1215 |
+ int prec = iSource.getChar(); |
| 1216 |
+ height = read16(); |
| 1217 |
+ width = read16(); |
| 1218 |
+ numComps = iSource.getChar(); |
| 1219 |
+ if (prec != 8) { |
| 1220 |
+ ipeDebug("Bad DCT precision %d", prec); |
| 1221 |
+ return false; |
| 1222 |
+ } |
| 1223 |
+ for (int i = 0; i < numComps; ++i) { |
| 1224 |
+ compInfo[i].id = iSource.getChar(); |
| 1225 |
+ int c = iSource.getChar(); |
| 1226 |
+ compInfo[i].hSample = (c >> 4) & 0x0f; |
| 1227 |
+ compInfo[i].vSample = c & 0x0f; |
| 1228 |
+ compInfo[i].quantTable = iSource.getChar(); |
| 1229 |
+ } |
| 1230 |
+ progressive = false; |
| 1231 |
+ return true; |
| 1232 |
+} |
| 1233 |
+ |
| 1234 |
+bool DCTStream::readProgressiveSOF() |
| 1235 |
+{ |
| 1236 |
+ (void) read16(); // length |
| 1237 |
+ int prec = iSource.getChar(); |
| 1238 |
+ height = read16(); |
| 1239 |
+ width = read16(); |
| 1240 |
+ numComps = iSource.getChar(); |
| 1241 |
+ if (prec != 8) { |
| 1242 |
+ ipeDebug("Bad DCT precision %d", prec); |
| 1243 |
+ return false; |
| 1244 |
+ } |
| 1245 |
+ for (int i = 0; i < numComps; ++i) { |
| 1246 |
+ compInfo[i].id = iSource.getChar(); |
| 1247 |
+ int c = iSource.getChar(); |
| 1248 |
+ compInfo[i].hSample = (c >> 4) & 0x0f; |
| 1249 |
+ compInfo[i].vSample = c & 0x0f; |
| 1250 |
+ compInfo[i].quantTable = iSource.getChar(); |
| 1251 |
+ } |
| 1252 |
+ progressive = true; |
| 1253 |
+ return true; |
| 1254 |
+} |
| 1255 |
+ |
| 1256 |
+bool DCTStream::readScanInfo() |
| 1257 |
+{ |
| 1258 |
+ int length; |
| 1259 |
+ int id, c; |
| 1260 |
+ int i, j; |
| 1261 |
+ |
| 1262 |
+ length = read16() - 2; |
| 1263 |
+ scanInfo.numComps = iSource.getChar(); |
| 1264 |
+ --length; |
| 1265 |
+ if (length != 2 * scanInfo.numComps + 3) { |
| 1266 |
+ ipeDebug("Bad DCT scan info block"); |
| 1267 |
+ return false; |
| 1268 |
+ } |
| 1269 |
+ interleaved = scanInfo.numComps == numComps; |
| 1270 |
+ for (j = 0; j < numComps; ++j) { |
| 1271 |
+ scanInfo.comp[j] = false; |
| 1272 |
+ } |
| 1273 |
+ for (i = 0; i < scanInfo.numComps; ++i) { |
| 1274 |
+ id = iSource.getChar(); |
| 1275 |
+ for (j = 0; j < numComps; ++j) { |
| 1276 |
+ if (id == compInfo[j].id) { |
| 1277 |
+ break; |
| 1278 |
+ } |
| 1279 |
+ } |
| 1280 |
+ if (j == numComps) { |
| 1281 |
+ ipeDebug("Bad DCT component ID in scan info block"); |
| 1282 |
+ return false; |
| 1283 |
+ } |
| 1284 |
+ scanInfo.comp[j] = true; |
| 1285 |
+ c = iSource.getChar(); |
| 1286 |
+ scanInfo.dcHuffTable[j] = (c >> 4) & 0x0f; |
| 1287 |
+ scanInfo.acHuffTable[j] = c & 0x0f; |
| 1288 |
+ } |
| 1289 |
+ scanInfo.firstCoeff = iSource.getChar(); |
| 1290 |
+ scanInfo.lastCoeff = iSource.getChar(); |
| 1291 |
+ c = iSource.getChar(); |
| 1292 |
+ scanInfo.ah = (c >> 4) & 0x0f; |
| 1293 |
+ scanInfo.al = c & 0x0f; |
| 1294 |
+ return true; |
| 1295 |
+} |
| 1296 |
+ |
| 1297 |
+bool DCTStream::readQuantTables() |
| 1298 |
+{ |
| 1299 |
+ int length; |
| 1300 |
+ int i; |
| 1301 |
+ int index; |
| 1302 |
+ |
| 1303 |
+ length = read16() - 2; |
| 1304 |
+ while (length > 0) { |
| 1305 |
+ index = iSource.getChar(); |
| 1306 |
+ if ((index & 0xf0) || index >= 4) { |
| 1307 |
+ ipeDebug("Bad DCT quantization table"); |
| 1308 |
+ return false; |
| 1309 |
+ } |
| 1310 |
+ if (index == numQuantTables) |
| 1311 |
+ numQuantTables = index + 1; |
| 1312 |
+ for (i = 0; i < 64; ++i) |
| 1313 |
+ quantTables[index][dctZigZag[i]] = uchar(iSource.getChar()); |
| 1314 |
+ length -= 65; |
| 1315 |
+ } |
| 1316 |
+ return true; |
| 1317 |
+} |
| 1318 |
+ |
| 1319 |
+bool DCTStream::readHuffmanTables() |
| 1320 |
+{ |
| 1321 |
+ DCTHuffTable *tbl; |
| 1322 |
+ int length; |
| 1323 |
+ int index; |
| 1324 |
+ ushort code; |
| 1325 |
+ uchar sym; |
| 1326 |
+ int i; |
| 1327 |
+ int c; |
| 1328 |
+ |
| 1329 |
+ length = read16() - 2; |
| 1330 |
+ while (length > 0) { |
| 1331 |
+ index = iSource.getChar(); |
| 1332 |
+ --length; |
| 1333 |
+ if ((index & 0x0f) >= 4) { |
| 1334 |
+ ipeDebug("Bad DCT Huffman table"); |
| 1335 |
+ return false; |
| 1336 |
+ } |
| 1337 |
+ if (index & 0x10) { |
| 1338 |
+ index &= 0x0f; |
| 1339 |
+ if (index >= numACHuffTables) |
| 1340 |
+ numACHuffTables = index+1; |
| 1341 |
+ tbl = &acHuffTables[index]; |
| 1342 |
+ } else { |
| 1343 |
+ if (index >= numDCHuffTables) |
| 1344 |
+ numDCHuffTables = index+1; |
| 1345 |
+ tbl = &dcHuffTables[index]; |
| 1346 |
+ } |
| 1347 |
+ sym = 0; |
| 1348 |
+ code = 0; |
| 1349 |
+ for (i = 1; i <= 16; ++i) { |
| 1350 |
+ c = iSource.getChar(); |
| 1351 |
+ tbl->firstSym[i] = sym; |
| 1352 |
+ tbl->firstCode[i] = code; |
| 1353 |
+ tbl->numCodes[i] = ushort(c); |
| 1354 |
+ sym += uchar(c); |
| 1355 |
+ code = ushort((code + c) << 1); |
| 1356 |
+ } |
| 1357 |
+ length -= 16; |
| 1358 |
+ for (i = 0; i < sym; ++i) |
| 1359 |
+ tbl->sym[i] = uchar(iSource.getChar()); |
| 1360 |
+ length -= sym; |
| 1361 |
+ } |
| 1362 |
+ return true; |
| 1363 |
+} |
| 1364 |
+ |
| 1365 |
+bool DCTStream::readRestartInterval() |
| 1366 |
+{ |
| 1367 |
+ int length; |
| 1368 |
+ |
| 1369 |
+ length = read16(); |
| 1370 |
+ if (length != 4) { |
| 1371 |
+ ipeDebug("Bad DCT restart interval"); |
| 1372 |
+ return false; |
| 1373 |
+ } |
| 1374 |
+ restartInterval = read16(); |
| 1375 |
+ return true; |
| 1376 |
+} |
| 1377 |
+ |
| 1378 |
+bool DCTStream::readAdobeMarker() |
| 1379 |
+{ |
| 1380 |
+ int length, i; |
| 1381 |
+ char buf[12]; |
| 1382 |
+ int c; |
| 1383 |
+ |
| 1384 |
+ length = read16(); |
| 1385 |
+ if (length < 14) { |
| 1386 |
+ goto err; |
| 1387 |
+ } |
| 1388 |
+ for (i = 0; i < 12; ++i) { |
| 1389 |
+ if ((c = iSource.getChar()) == EOF) { |
| 1390 |
+ goto err; |
| 1391 |
+ } |
| 1392 |
+ buf[i] = char(c); |
| 1393 |
+ } |
| 1394 |
+ if (::strncmp(buf, "Adobe", 5)) { |
| 1395 |
+ goto err; |
| 1396 |
+ } |
| 1397 |
+ colorXform = buf[11]; |
| 1398 |
+ gotAdobeMarker = true; |
| 1399 |
+ for (i = 14; i < length; ++i) { |
| 1400 |
+ if (iSource.getChar() == EOF) { |
| 1401 |
+ goto err; |
| 1402 |
+ } |
| 1403 |
+ } |
| 1404 |
+ return true; |
| 1405 |
+ |
| 1406 |
+ err: |
| 1407 |
+ ipeDebug("Bad DCT Adobe APP14 marker"); |
| 1408 |
+ return false; |
| 1409 |
+} |
| 1410 |
+ |
| 1411 |
+bool DCTStream::readTrailer() |
| 1412 |
+{ |
| 1413 |
+ int c; |
| 1414 |
+ |
| 1415 |
+ c = readMarker(); |
| 1416 |
+ if (c != 0xd9) { // EOI |
| 1417 |
+ ipeDebug("Bad DCT trailer"); |
| 1418 |
+ return false; |
| 1419 |
+ } |
| 1420 |
+ return true; |
| 1421 |
+} |
| 1422 |
+ |
| 1423 |
+int DCTStream::readMarker() |
| 1424 |
+{ |
| 1425 |
+ int c; |
| 1426 |
+ |
| 1427 |
+ do { |
| 1428 |
+ do { |
| 1429 |
+ c = iSource.getChar(); |
| 1430 |
+ } while (c != 0xff); |
| 1431 |
+ do { |
| 1432 |
+ c = iSource.getChar(); |
| 1433 |
+ } while (c == 0xff); |
| 1434 |
+ } while (c == 0x00); |
| 1435 |
+ return c; |
| 1436 |
+} |
| 1437 |
+ |
| 1438 |
+int DCTStream::read16() |
| 1439 |
+{ |
| 1440 |
+ int c1, c2; |
| 1441 |
+ |
| 1442 |
+ if ((c1 = iSource.getChar()) == EOF) |
| 1443 |
+ return EOF; |
| 1444 |
+ if ((c2 = iSource.getChar()) == EOF) |
| 1445 |
+ return EOF; |
| 1446 |
+ return (c1 << 8) + c2; |
| 1447 |
+} |
| 1448 |
+ |
| 1449 |
+// -------------------------------------------------------------------- |
| 1450 |
+ |
| 1451 |
+bool dctDecode(Buffer dctData, Buffer pixelData) |
| 1452 |
+{ |
| 1453 |
+ // ipeDebug("dctDecode %d, %d", dctData.size(), pixelData.size()); |
| 1454 |
+ BufferSource source(dctData); |
| 1455 |
+ DCTStream dct(source); |
| 1456 |
+ dct.reset(); |
| 1457 |
+ char *p = pixelData.data(); |
| 1458 |
+ int n = pixelData.size(); |
| 1459 |
+ while (n--) { |
| 1460 |
+ int c = dct.getChar(); |
| 1461 |
+ if (c == EOF) |
| 1462 |
+ return false; |
| 1463 |
+ *p++ = char(c); |
| 1464 |
+ } |
| 1465 |
+ return true; |
| 1466 |
+} |
| 1467 |
+ |
| 1468 |
+// -------------------------------------------------------------------- |