1/* 2 * Copyright (C) 2006 Apple Inc. 3 * 4 * Portions are Copyright (C) 2001-6 mozilla.org 5 * 6 * Other contributors: 7 * Stuart Parmenter <stuart@mozilla.com> 8 * 9 * Copyright (C) 2007-2009 Torch Mobile, Inc. 10 * 11 * This library is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU Lesser General Public 13 * License as published by the Free Software Foundation; either 14 * version 2.1 of the License, or (at your option) any later version. 15 * 16 * This library is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 19 * Lesser General Public License for more details. 20 * 21 * You should have received a copy of the GNU Lesser General Public 22 * License along with this library; if not, write to the Free Software 23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 24 * 25 * Alternatively, the contents of this file may be used under the terms 26 * of either the Mozilla Public License Version 1.1, found at 27 * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public 28 * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html 29 * (the "GPL"), in which case the provisions of the MPL or the GPL are 30 * applicable instead of those above. If you wish to allow use of your 31 * version of this file only under the terms of one of those two 32 * licenses (the MPL or the GPL) and not to allow others to use your 33 * version of this file under the LGPL, indicate your decision by 34 * deletingthe provisions above and replace them with the notice and 35 * other provisions required by the MPL or the GPL, as the case may be. 36 * If you do not delete the provisions above, a recipient may use your 37 * version of this file under any of the LGPL, the MPL or the GPL. 38 */ 39 40#include "config.h" 41#include "JPEGImageDecoder.h" 42#include <wtf/PassOwnPtr.h> 43 44extern "C" { 45#if USE(ICCJPEG) 46#include "iccjpeg.h" 47#endif 48#if USE(QCMSLIB) 49#include "qcms.h" 50#endif 51#include <setjmp.h> 52} 53 54#if CPU(BIG_ENDIAN) || CPU(MIDDLE_ENDIAN) 55#define ASSUME_LITTLE_ENDIAN 0 56#else 57#define ASSUME_LITTLE_ENDIAN 1 58#endif 59 60#if defined(JCS_ALPHA_EXTENSIONS) && ASSUME_LITTLE_ENDIAN 61#define TURBO_JPEG_RGB_SWIZZLE 62inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_EXT_BGRA; } 63inline bool turboSwizzled(J_COLOR_SPACE colorSpace) { return colorSpace == JCS_EXT_RGBA || colorSpace == JCS_EXT_BGRA; } 64inline bool colorSpaceHasAlpha(J_COLOR_SPACE colorSpace) { return turboSwizzled(colorSpace); } 65#else 66inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_RGB; } 67inline bool colorSpaceHasAlpha(J_COLOR_SPACE) { return false; } 68#endif 69 70#if USE(LOW_QUALITY_IMAGE_NO_JPEG_DITHERING) 71inline J_DCT_METHOD dctMethod() { return JDCT_IFAST; } 72inline J_DITHER_MODE ditherMode() { return JDITHER_NONE; } 73#else 74inline J_DCT_METHOD dctMethod() { return JDCT_ISLOW; } 75inline J_DITHER_MODE ditherMode() { return JDITHER_FS; } 76#endif 77 78#if USE(LOW_QUALITY_IMAGE_NO_JPEG_FANCY_UPSAMPLING) 79inline bool doFancyUpsampling() { return false; } 80#else 81inline bool doFancyUpsampling() { return true; } 82#endif 83 84const int exifMarker = JPEG_APP0 + 1; 85 86namespace WebCore { 87 88struct decoder_error_mgr { 89 struct jpeg_error_mgr pub; // "public" fields for IJG library 90 jmp_buf setjmp_buffer; // For handling catastropic errors 91}; 92 93enum jstate { 94 JPEG_HEADER, // Reading JFIF headers 95 JPEG_START_DECOMPRESS, 96 JPEG_DECOMPRESS_PROGRESSIVE, // Output progressive pixels 97 JPEG_DECOMPRESS_SEQUENTIAL, // Output sequential pixels 98 JPEG_DONE, 99 JPEG_ERROR 100}; 101 102void init_source(j_decompress_ptr jd); 103boolean fill_input_buffer(j_decompress_ptr jd); 104void skip_input_data(j_decompress_ptr jd, long num_bytes); 105void term_source(j_decompress_ptr jd); 106void error_exit(j_common_ptr cinfo); 107 108// Implementation of a JPEG src object that understands our state machine 109struct decoder_source_mgr { 110 // public fields; must be first in this struct! 111 struct jpeg_source_mgr pub; 112 113 JPEGImageReader* decoder; 114}; 115 116static unsigned readUint16(JOCTET* data, bool isBigEndian) 117{ 118 if (isBigEndian) 119 return (GETJOCTET(data[0]) << 8) | GETJOCTET(data[1]); 120 return (GETJOCTET(data[1]) << 8) | GETJOCTET(data[0]); 121} 122 123static unsigned readUint32(JOCTET* data, bool isBigEndian) 124{ 125 if (isBigEndian) 126 return (GETJOCTET(data[0]) << 24) | (GETJOCTET(data[1]) << 16) | (GETJOCTET(data[2]) << 8) | GETJOCTET(data[3]); 127 return (GETJOCTET(data[3]) << 24) | (GETJOCTET(data[2]) << 16) | (GETJOCTET(data[1]) << 8) | GETJOCTET(data[0]); 128} 129 130static bool checkExifHeader(jpeg_saved_marker_ptr marker, bool& isBigEndian, unsigned& ifdOffset) 131{ 132 // For exif data, the APP1 block is followed by 'E', 'x', 'i', 'f', '\0', 133 // then a fill byte, and then a tiff file that contains the metadata. 134 // A tiff file starts with 'I', 'I' (intel / little endian byte order) or 135 // 'M', 'M' (motorola / big endian byte order), followed by (uint16_t)42, 136 // followed by an uint32_t with the offset to the tag block, relative to the 137 // tiff file start. 138 const unsigned exifHeaderSize = 14; 139 if (!(marker->marker == exifMarker 140 && marker->data_length >= exifHeaderSize 141 && marker->data[0] == 'E' 142 && marker->data[1] == 'x' 143 && marker->data[2] == 'i' 144 && marker->data[3] == 'f' 145 && marker->data[4] == '\0' 146 // data[5] is a fill byte 147 && ((marker->data[6] == 'I' && marker->data[7] == 'I') 148 || (marker->data[6] == 'M' && marker->data[7] == 'M')))) 149 return false; 150 151 isBigEndian = marker->data[6] == 'M'; 152 if (readUint16(marker->data + 8, isBigEndian) != 42) 153 return false; 154 155 ifdOffset = readUint32(marker->data + 10, isBigEndian); 156 return true; 157} 158 159static ImageOrientation readImageOrientation(jpeg_decompress_struct* info) 160{ 161 // The JPEG decoder looks at EXIF metadata. 162 // FIXME: Possibly implement XMP and IPTC support. 163 const unsigned orientationTag = 0x112; 164 const unsigned shortType = 3; 165 for (jpeg_saved_marker_ptr marker = info->marker_list; marker; marker = marker->next) { 166 bool isBigEndian; 167 unsigned ifdOffset; 168 if (!checkExifHeader(marker, isBigEndian, ifdOffset)) 169 continue; 170 const unsigned offsetToTiffData = 6; // Account for 'Exif\0<fill byte>' header. 171 if (marker->data_length < offsetToTiffData || ifdOffset >= marker->data_length - offsetToTiffData) 172 continue; 173 ifdOffset += offsetToTiffData; 174 175 // The jpeg exif container format contains a tiff block for metadata. 176 // A tiff image file directory (ifd) consists of a uint16_t describing 177 // the number of ifd entries, followed by that many entries. 178 // When touching this code, it's useful to look at the tiff spec: 179 // http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf 180 JOCTET* ifd = marker->data + ifdOffset; 181 JOCTET* end = marker->data + marker->data_length; 182 if (end - ifd < 2) 183 continue; 184 unsigned tagCount = readUint16(ifd, isBigEndian); 185 ifd += 2; // Skip over the uint16 that was just read. 186 187 // Every ifd entry is 2 bytes of tag, 2 bytes of contents datatype, 188 // 4 bytes of number-of-elements, and 4 bytes of either offset to the 189 // tag data, or if the data is small enough, the inlined data itself. 190 const int ifdEntrySize = 12; 191 for (unsigned i = 0; i < tagCount && end - ifd >= ifdEntrySize; ++i, ifd += ifdEntrySize) { 192 unsigned tag = readUint16(ifd, isBigEndian); 193 unsigned type = readUint16(ifd + 2, isBigEndian); 194 unsigned count = readUint32(ifd + 4, isBigEndian); 195 if (tag == orientationTag && type == shortType && count == 1) 196 return ImageOrientation::fromEXIFValue(readUint16(ifd + 8, isBigEndian)); 197 } 198 } 199 200 return ImageOrientation(); 201} 202 203static ColorProfile readColorProfile(jpeg_decompress_struct* info) 204{ 205#if USE(ICCJPEG) 206 JOCTET* profile; 207 unsigned int profileLength; 208 209 if (!read_icc_profile(info, &profile, &profileLength)) 210 return ColorProfile(); 211 212 // Only accept RGB color profiles from input class devices. 213 bool ignoreProfile = false; 214 char* profileData = reinterpret_cast<char*>(profile); 215 if (profileLength < ImageDecoder::iccColorProfileHeaderLength) 216 ignoreProfile = true; 217 else if (!ImageDecoder::rgbColorProfile(profileData, profileLength)) 218 ignoreProfile = true; 219 else if (!ImageDecoder::inputDeviceColorProfile(profileData, profileLength)) 220 ignoreProfile = true; 221 222 ColorProfile colorProfile; 223 if (!ignoreProfile) 224 colorProfile.append(profileData, profileLength); 225 free(profile); 226 return colorProfile; 227#else 228 UNUSED_PARAM(info); 229 return ColorProfile(); 230#endif 231} 232 233class JPEGImageReader { 234 WTF_MAKE_FAST_ALLOCATED; 235public: 236 JPEGImageReader(JPEGImageDecoder* decoder) 237 : m_decoder(decoder) 238 , m_bufferLength(0) 239 , m_bytesToSkip(0) 240 , m_state(JPEG_HEADER) 241 , m_samples(0) 242#if USE(QCMSLIB) 243 , m_transform(0) 244#endif 245 { 246 memset(&m_info, 0, sizeof(jpeg_decompress_struct)); 247 248 // We set up the normal JPEG error routines, then override error_exit. 249 m_info.err = jpeg_std_error(&m_err.pub); 250 m_err.pub.error_exit = error_exit; 251 252 // Allocate and initialize JPEG decompression object. 253 jpeg_create_decompress(&m_info); 254 255 decoder_source_mgr* src = 0; 256 if (!m_info.src) { 257 src = (decoder_source_mgr*)fastCalloc(sizeof(decoder_source_mgr), 1); 258 if (!src) { 259 m_state = JPEG_ERROR; 260 return; 261 } 262 } 263 264 m_info.src = (jpeg_source_mgr*)src; 265 266 // Set up callback functions. 267 src->pub.init_source = init_source; 268 src->pub.fill_input_buffer = fill_input_buffer; 269 src->pub.skip_input_data = skip_input_data; 270 src->pub.resync_to_restart = jpeg_resync_to_restart; 271 src->pub.term_source = term_source; 272 src->decoder = this; 273 274#if USE(ICCJPEG) 275 // Retain ICC color profile markers for color management. 276 setup_read_icc_profile(&m_info); 277#endif 278 279 // Keep APP1 blocks, for obtaining exif data. 280 jpeg_save_markers(&m_info, exifMarker, 0xFFFF); 281 } 282 283 ~JPEGImageReader() 284 { 285 close(); 286 } 287 288 void close() 289 { 290 decoder_source_mgr* src = (decoder_source_mgr*)m_info.src; 291 if (src) 292 fastFree(src); 293 m_info.src = 0; 294 295#if USE(QCMSLIB) 296 if (m_transform) 297 qcms_transform_release(m_transform); 298 m_transform = 0; 299#endif 300 jpeg_destroy_decompress(&m_info); 301 } 302 303 void skipBytes(long numBytes) 304 { 305 decoder_source_mgr* src = (decoder_source_mgr*)m_info.src; 306 long bytesToSkip = std::min(numBytes, (long)src->pub.bytes_in_buffer); 307 src->pub.bytes_in_buffer -= (size_t)bytesToSkip; 308 src->pub.next_input_byte += bytesToSkip; 309 310 m_bytesToSkip = std::max(numBytes - bytesToSkip, static_cast<long>(0)); 311 } 312 313 bool decode(const SharedBuffer& data, bool onlySize) 314 { 315 m_decodingSizeOnly = onlySize; 316 317 unsigned newByteCount = data.size() - m_bufferLength; 318 unsigned readOffset = m_bufferLength - m_info.src->bytes_in_buffer; 319 320 m_info.src->bytes_in_buffer += newByteCount; 321 m_info.src->next_input_byte = (JOCTET*)(data.data()) + readOffset; 322 323 // If we still have bytes to skip, try to skip those now. 324 if (m_bytesToSkip) 325 skipBytes(m_bytesToSkip); 326 327 m_bufferLength = data.size(); 328 329 // We need to do the setjmp here. Otherwise bad things will happen 330 if (setjmp(m_err.setjmp_buffer)) 331 return m_decoder->setFailed(); 332 333 switch (m_state) { 334 case JPEG_HEADER: 335 // Read file parameters with jpeg_read_header(). 336 if (jpeg_read_header(&m_info, TRUE) == JPEG_SUSPENDED) 337 return false; // I/O suspension. 338 339 switch (m_info.jpeg_color_space) { 340 case JCS_GRAYSCALE: 341 case JCS_RGB: 342 case JCS_YCbCr: 343 // libjpeg can convert GRAYSCALE and YCbCr image pixels to RGB. 344 m_info.out_color_space = rgbOutputColorSpace(); 345#if defined(TURBO_JPEG_RGB_SWIZZLE) 346 if (m_info.saw_JFIF_marker) 347 break; 348 // FIXME: Swizzle decoding does not support Adobe transform=0 349 // images (yet), so revert to using JSC_RGB in that case. 350 if (m_info.saw_Adobe_marker && !m_info.Adobe_transform) 351 m_info.out_color_space = JCS_RGB; 352#endif 353 break; 354 case JCS_CMYK: 355 case JCS_YCCK: 356 // libjpeg can convert YCCK to CMYK, but neither to RGB, so we 357 // manually convert CMKY to RGB. 358 m_info.out_color_space = JCS_CMYK; 359 break; 360 default: 361 return m_decoder->setFailed(); 362 } 363 364 m_state = JPEG_START_DECOMPRESS; 365 366 // We can fill in the size now that the header is available. 367 if (!m_decoder->setSize(m_info.image_width, m_info.image_height)) 368 return false; 369 370 m_decoder->setOrientation(readImageOrientation(info())); 371 372#if ENABLE(IMAGE_DECODER_DOWN_SAMPLING) && defined(TURBO_JPEG_RGB_SWIZZLE) 373 // There's no point swizzle decoding if image down sampling will 374 // be applied. Revert to using JSC_RGB in that case. 375 if (m_decoder->willDownSample() && turboSwizzled(m_info.out_color_space)) 376 m_info.out_color_space = JCS_RGB; 377#endif 378 // Allow color management of the decoded RGBA pixels if possible. 379 if (!m_decoder->ignoresGammaAndColorProfile()) { 380 ColorProfile rgbInputDeviceColorProfile = readColorProfile(info()); 381 if (!rgbInputDeviceColorProfile.isEmpty()) 382 m_decoder->setColorProfile(rgbInputDeviceColorProfile); 383#if USE(QCMSLIB) 384 createColorTransform(rgbInputDeviceColorProfile, colorSpaceHasAlpha(m_info.out_color_space)); 385#if defined(TURBO_JPEG_RGB_SWIZZLE) 386 // Input RGBA data to qcms. Note: restored to BGRA on output. 387 if (m_transform && m_info.out_color_space == JCS_EXT_BGRA) 388 m_info.out_color_space = JCS_EXT_RGBA; 389#endif 390#endif 391 } 392 393 // Don't allocate a giant and superfluous memory buffer when the 394 // image is a sequential JPEG. 395 m_info.buffered_image = jpeg_has_multiple_scans(&m_info); 396 397 // Used to set up image size so arrays can be allocated. 398 jpeg_calc_output_dimensions(&m_info); 399 400 // Make a one-row-high sample array that will go away when done with 401 // image. Always make it big enough to hold an RGB row. Since this 402 // uses the IJG memory manager, it must be allocated before the call 403 // to jpeg_start_compress(). 404 // FIXME: note that some output color spaces do not need the samples 405 // buffer. Remove this allocation for those color spaces. 406 m_samples = (*m_info.mem->alloc_sarray)((j_common_ptr) &m_info, JPOOL_IMAGE, m_info.output_width * 4, 1); 407 408 if (m_decodingSizeOnly) { 409 // We can stop here. Reduce our buffer length and available data. 410 m_bufferLength -= m_info.src->bytes_in_buffer; 411 m_info.src->bytes_in_buffer = 0; 412 return true; 413 } 414 // FALL THROUGH 415 416 case JPEG_START_DECOMPRESS: 417 // Set parameters for decompression. 418 // FIXME -- Should reset dct_method and dither mode for final pass 419 // of progressive JPEG. 420 m_info.dct_method = dctMethod(); 421 m_info.dither_mode = ditherMode(); 422 m_info.do_fancy_upsampling = doFancyUpsampling() ? TRUE : FALSE; 423 m_info.enable_2pass_quant = FALSE; 424 m_info.do_block_smoothing = TRUE; 425 426 // Start decompressor. 427 if (!jpeg_start_decompress(&m_info)) 428 return false; // I/O suspension. 429 430 // If this is a progressive JPEG ... 431 m_state = (m_info.buffered_image) ? JPEG_DECOMPRESS_PROGRESSIVE : JPEG_DECOMPRESS_SEQUENTIAL; 432 // FALL THROUGH 433 434 case JPEG_DECOMPRESS_SEQUENTIAL: 435 if (m_state == JPEG_DECOMPRESS_SEQUENTIAL) { 436 437 if (!m_decoder->outputScanlines()) 438 return false; // I/O suspension. 439 440 // If we've completed image output... 441 ASSERT(m_info.output_scanline == m_info.output_height); 442 m_state = JPEG_DONE; 443 } 444 // FALL THROUGH 445 446 case JPEG_DECOMPRESS_PROGRESSIVE: 447 if (m_state == JPEG_DECOMPRESS_PROGRESSIVE) { 448 int status; 449 do { 450 status = jpeg_consume_input(&m_info); 451 } while ((status != JPEG_SUSPENDED) && (status != JPEG_REACHED_EOI)); 452 453 for (;;) { 454 if (!m_info.output_scanline) { 455 int scan = m_info.input_scan_number; 456 457 // If we haven't displayed anything yet 458 // (output_scan_number == 0) and we have enough data for 459 // a complete scan, force output of the last full scan. 460 if (!m_info.output_scan_number && (scan > 1) && (status != JPEG_REACHED_EOI)) 461 --scan; 462 463 if (!jpeg_start_output(&m_info, scan)) 464 return false; // I/O suspension. 465 } 466 467 if (m_info.output_scanline == 0xffffff) 468 m_info.output_scanline = 0; 469 470 // If outputScanlines() fails, it deletes |this|. Therefore, 471 // copy the decoder pointer and use it to check for failure 472 // to avoid member access in the failure case. 473 JPEGImageDecoder* decoder = m_decoder; 474 if (!decoder->outputScanlines()) { 475 if (decoder->failed()) // Careful; |this| is deleted. 476 return false; 477 if (!m_info.output_scanline) 478 // Didn't manage to read any lines - flag so we 479 // don't call jpeg_start_output() multiple times for 480 // the same scan. 481 m_info.output_scanline = 0xffffff; 482 return false; // I/O suspension. 483 } 484 485 if (m_info.output_scanline == m_info.output_height) { 486 if (!jpeg_finish_output(&m_info)) 487 return false; // I/O suspension. 488 489 if (jpeg_input_complete(&m_info) && (m_info.input_scan_number == m_info.output_scan_number)) 490 break; 491 492 m_info.output_scanline = 0; 493 } 494 } 495 496 m_state = JPEG_DONE; 497 } 498 // FALL THROUGH 499 500 case JPEG_DONE: 501 // Finish decompression. 502 return jpeg_finish_decompress(&m_info); 503 504 case JPEG_ERROR: 505 // We can get here if the constructor failed. 506 return m_decoder->setFailed(); 507 } 508 509 return true; 510 } 511 512 jpeg_decompress_struct* info() { return &m_info; } 513 JSAMPARRAY samples() const { return m_samples; } 514 JPEGImageDecoder* decoder() { return m_decoder; } 515#if USE(QCMSLIB) 516 qcms_transform* colorTransform() const { return m_transform; } 517 518 void createColorTransform(const ColorProfile& colorProfile, bool hasAlpha) 519 { 520 if (m_transform) 521 qcms_transform_release(m_transform); 522 m_transform = 0; 523 524 if (colorProfile.isEmpty()) 525 return; 526 qcms_profile* deviceProfile = ImageDecoder::qcmsOutputDeviceProfile(); 527 if (!deviceProfile) 528 return; 529 qcms_profile* inputProfile = qcms_profile_from_memory(colorProfile.data(), colorProfile.size()); 530 if (!inputProfile) 531 return; 532 // We currently only support color profiles for RGB profiled images. 533 ASSERT(icSigRgbData == qcms_profile_get_color_space(inputProfile)); 534 qcms_data_type dataFormat = hasAlpha ? QCMS_DATA_RGBA_8 : QCMS_DATA_RGB_8; 535 // FIXME: Don't force perceptual intent if the image profile contains an intent. 536 m_transform = qcms_transform_create(inputProfile, dataFormat, deviceProfile, dataFormat, QCMS_INTENT_PERCEPTUAL); 537 qcms_profile_release(inputProfile); 538 } 539#endif 540 541private: 542 JPEGImageDecoder* m_decoder; 543 unsigned m_bufferLength; 544 int m_bytesToSkip; 545 bool m_decodingSizeOnly; 546 547 jpeg_decompress_struct m_info; 548 decoder_error_mgr m_err; 549 jstate m_state; 550 551 JSAMPARRAY m_samples; 552 553#if USE(QCMSLIB) 554 qcms_transform* m_transform; 555#endif 556}; 557 558// Override the standard error method in the IJG JPEG decoder code. 559void error_exit(j_common_ptr cinfo) 560{ 561 // Return control to the setjmp point. 562 decoder_error_mgr *err = reinterpret_cast_ptr<decoder_error_mgr *>(cinfo->err); 563 longjmp(err->setjmp_buffer, -1); 564} 565 566void init_source(j_decompress_ptr) 567{ 568} 569 570void skip_input_data(j_decompress_ptr jd, long num_bytes) 571{ 572 decoder_source_mgr *src = (decoder_source_mgr *)jd->src; 573 src->decoder->skipBytes(num_bytes); 574} 575 576boolean fill_input_buffer(j_decompress_ptr) 577{ 578 // Our decode step always sets things up properly, so if this method is ever 579 // called, then we have hit the end of the buffer. A return value of false 580 // indicates that we have no data to supply yet. 581 return FALSE; 582} 583 584void term_source(j_decompress_ptr jd) 585{ 586 decoder_source_mgr *src = (decoder_source_mgr *)jd->src; 587 src->decoder->decoder()->jpegComplete(); 588} 589 590JPEGImageDecoder::JPEGImageDecoder(ImageSource::AlphaOption alphaOption, 591 ImageSource::GammaAndColorProfileOption gammaAndColorProfileOption) 592 : ImageDecoder(alphaOption, gammaAndColorProfileOption) 593{ 594} 595 596JPEGImageDecoder::~JPEGImageDecoder() 597{ 598} 599 600bool JPEGImageDecoder::isSizeAvailable() 601{ 602 if (!ImageDecoder::isSizeAvailable()) 603 decode(true); 604 605 return ImageDecoder::isSizeAvailable(); 606} 607 608bool JPEGImageDecoder::setSize(unsigned width, unsigned height) 609{ 610 if (!ImageDecoder::setSize(width, height)) 611 return false; 612 613 prepareScaleDataIfNecessary(); 614 return true; 615} 616 617ImageFrame* JPEGImageDecoder::frameBufferAtIndex(size_t index) 618{ 619 if (index) 620 return 0; 621 622 if (m_frameBufferCache.isEmpty()) { 623 m_frameBufferCache.resize(1); 624 m_frameBufferCache[0].setPremultiplyAlpha(m_premultiplyAlpha); 625 } 626 627 ImageFrame& frame = m_frameBufferCache[0]; 628 if (frame.status() != ImageFrame::FrameComplete) 629 decode(false); 630 return &frame; 631} 632 633bool JPEGImageDecoder::setFailed() 634{ 635 m_reader.clear(); 636 return ImageDecoder::setFailed(); 637} 638 639template <J_COLOR_SPACE colorSpace> 640void setPixel(ImageFrame& buffer, ImageFrame::PixelData* currentAddress, JSAMPARRAY samples, int column) 641{ 642 JSAMPLE* jsample = *samples + column * (colorSpace == JCS_RGB ? 3 : 4); 643 644 switch (colorSpace) { 645 case JCS_RGB: 646 buffer.setRGBA(currentAddress, jsample[0], jsample[1], jsample[2], 0xFF); 647 break; 648 case JCS_CMYK: 649 // Source is 'Inverted CMYK', output is RGB. 650 // See: http://www.easyrgb.com/math.php?MATH=M12#text12 651 // Or: http://www.ilkeratalay.com/colorspacesfaq.php#rgb 652 // From CMYK to CMY: 653 // X = X * (1 - K ) + K [for X = C, M, or Y] 654 // Thus, from Inverted CMYK to CMY is: 655 // X = (1-iX) * (1 - (1-iK)) + (1-iK) => 1 - iX*iK 656 // From CMY (0..1) to RGB (0..1): 657 // R = 1 - C => 1 - (1 - iC*iK) => iC*iK [G and B similar] 658 unsigned k = jsample[3]; 659 buffer.setRGBA(currentAddress, jsample[0] * k / 255, jsample[1] * k / 255, jsample[2] * k / 255, 0xFF); 660 break; 661 } 662} 663 664template <J_COLOR_SPACE colorSpace, bool isScaled> 665bool JPEGImageDecoder::outputScanlines(ImageFrame& buffer) 666{ 667 JSAMPARRAY samples = m_reader->samples(); 668 jpeg_decompress_struct* info = m_reader->info(); 669 int width = isScaled ? m_scaledColumns.size() : info->output_width; 670 671 while (info->output_scanline < info->output_height) { 672 // jpeg_read_scanlines will increase the scanline counter, so we 673 // save the scanline before calling it. 674 int sourceY = info->output_scanline; 675 /* Request one scanline. Returns 0 or 1 scanlines. */ 676 if (jpeg_read_scanlines(info, samples, 1) != 1) 677 return false; 678 679 int destY = scaledY(sourceY); 680 if (destY < 0) 681 continue; 682 683#if USE(QCMSLIB) 684 if (m_reader->colorTransform() && colorSpace == JCS_RGB) 685 qcms_transform_data(m_reader->colorTransform(), *samples, *samples, info->output_width); 686#endif 687 688 ImageFrame::PixelData* currentAddress = buffer.getAddr(0, destY); 689 for (int x = 0; x < width; ++x) { 690 setPixel<colorSpace>(buffer, currentAddress, samples, isScaled ? m_scaledColumns[x] : x); 691 ++currentAddress; 692 } 693 } 694 return true; 695} 696 697template <J_COLOR_SPACE colorSpace> 698bool JPEGImageDecoder::outputScanlines(ImageFrame& buffer) 699{ 700 return m_scaled ? outputScanlines<colorSpace, true>(buffer) : outputScanlines<colorSpace, false>(buffer); 701} 702 703bool JPEGImageDecoder::outputScanlines() 704{ 705 if (m_frameBufferCache.isEmpty()) 706 return false; 707 708 // Initialize the framebuffer if needed. 709 ImageFrame& buffer = m_frameBufferCache[0]; 710 if (buffer.status() == ImageFrame::FrameEmpty) { 711 if (!buffer.setSize(scaledSize().width(), scaledSize().height())) 712 return setFailed(); 713 buffer.setStatus(ImageFrame::FramePartial); 714 // The buffer is transparent outside the decoded area while the image is 715 // loading. The completed image will be marked fully opaque in jpegComplete(). 716 buffer.setHasAlpha(true); 717 buffer.setColorProfile(m_colorProfile); 718 719 // For JPEGs, the frame always fills the entire image. 720 buffer.setOriginalFrameRect(IntRect(IntPoint(), size())); 721 } 722 723 jpeg_decompress_struct* info = m_reader->info(); 724 725#if defined(TURBO_JPEG_RGB_SWIZZLE) 726 if (!m_scaled && turboSwizzled(info->out_color_space)) { 727 while (info->output_scanline < info->output_height) { 728 unsigned char* row = reinterpret_cast<unsigned char*>(buffer.getAddr(0, info->output_scanline)); 729 if (jpeg_read_scanlines(info, &row, 1) != 1) 730 return false; 731#if USE(QCMSLIB) 732 if (qcms_transform* transform = m_reader->colorTransform()) 733 qcms_transform_data_type(transform, row, row, info->output_width, rgbOutputColorSpace() == JCS_EXT_BGRA ? QCMS_OUTPUT_BGRX : QCMS_OUTPUT_RGBX); 734#endif 735 } 736 return true; 737 } 738#endif 739 740 switch (info->out_color_space) { 741 // The code inside outputScanlines<int, bool> will be executed 742 // for each pixel, so we want to avoid any extra comparisons there. 743 // That is why we use template and template specializations here so 744 // the proper code will be generated at compile time. 745 case JCS_RGB: 746 return outputScanlines<JCS_RGB>(buffer); 747 case JCS_CMYK: 748 return outputScanlines<JCS_CMYK>(buffer); 749 default: 750 ASSERT_NOT_REACHED(); 751 } 752 753 return setFailed(); 754} 755 756void JPEGImageDecoder::jpegComplete() 757{ 758 if (m_frameBufferCache.isEmpty()) 759 return; 760 761 // Hand back an appropriately sized buffer, even if the image ended up being 762 // empty. 763 ImageFrame& buffer = m_frameBufferCache[0]; 764 buffer.setHasAlpha(false); 765 buffer.setStatus(ImageFrame::FrameComplete); 766} 767 768void JPEGImageDecoder::decode(bool onlySize) 769{ 770 if (failed()) 771 return; 772 773 if (!m_reader) 774 m_reader = adoptPtr(new JPEGImageReader(this)); 775 776 // If we couldn't decode the image but we've received all the data, decoding 777 // has failed. 778 if (!m_reader->decode(*m_data, onlySize) && isAllDataReceived()) 779 setFailed(); 780 // If we're done decoding the image, we don't need the JPEGImageReader 781 // anymore. (If we failed, |m_reader| has already been cleared.) 782 else if (!m_frameBufferCache.isEmpty() && (m_frameBufferCache[0].status() == ImageFrame::FrameComplete)) 783 m_reader.clear(); 784} 785 786} 787