1/* 2 * Copyright (C) 2006 Apple Computer, 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 "PlatformInstrumentation.h" 43#include <wtf/PassOwnPtr.h> 44 45extern "C" { 46#if USE(ICCJPEG) 47#include "iccjpeg.h" 48#endif 49#if USE(QCMSLIB) 50#include "qcms.h" 51#endif 52#include <setjmp.h> 53} 54 55#if CPU(BIG_ENDIAN) || CPU(MIDDLE_ENDIAN) 56#define ASSUME_LITTLE_ENDIAN 0 57#else 58#define ASSUME_LITTLE_ENDIAN 1 59#endif 60 61#if defined(JCS_ALPHA_EXTENSIONS) && ASSUME_LITTLE_ENDIAN 62#define TURBO_JPEG_RGB_SWIZZLE 63inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_EXT_BGRA; } 64inline bool turboSwizzled(J_COLOR_SPACE colorSpace) { return colorSpace == JCS_EXT_RGBA || colorSpace == JCS_EXT_BGRA; } 65inline bool colorSpaceHasAlpha(J_COLOR_SPACE colorSpace) { return turboSwizzled(colorSpace); } 66#else 67inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_RGB; } 68inline bool colorSpaceHasAlpha(J_COLOR_SPACE) { return false; } 69#endif 70 71#if USE(LOW_QUALITY_IMAGE_NO_JPEG_DITHERING) 72inline J_DCT_METHOD dctMethod() { return JDCT_IFAST; } 73inline J_DITHER_MODE ditherMode() { return JDITHER_NONE; } 74#else 75inline J_DCT_METHOD dctMethod() { return JDCT_ISLOW; } 76inline J_DITHER_MODE ditherMode() { return JDITHER_FS; } 77#endif 78 79#if USE(LOW_QUALITY_IMAGE_NO_JPEG_FANCY_UPSAMPLING) 80inline bool doFancyUpsampling() { return false; } 81#else 82inline bool doFancyUpsampling() { return true; } 83#endif 84 85const int exifMarker = JPEG_APP0 + 1; 86 87namespace WebCore { 88 89struct decoder_error_mgr { 90 struct jpeg_error_mgr pub; // "public" fields for IJG library 91 jmp_buf setjmp_buffer; // For handling catastropic errors 92}; 93 94enum jstate { 95 JPEG_HEADER, // Reading JFIF headers 96 JPEG_START_DECOMPRESS, 97 JPEG_DECOMPRESS_PROGRESSIVE, // Output progressive pixels 98 JPEG_DECOMPRESS_SEQUENTIAL, // Output sequential pixels 99 JPEG_DONE, 100 JPEG_ERROR 101}; 102 103void init_source(j_decompress_ptr jd); 104boolean fill_input_buffer(j_decompress_ptr jd); 105void skip_input_data(j_decompress_ptr jd, long num_bytes); 106void term_source(j_decompress_ptr jd); 107#if PLATFORM(QT) 108void error_exit(j_common_ptr) NO_RETURN; 109#else 110void error_exit(j_common_ptr cinfo); 111#endif 112 113// Implementation of a JPEG src object that understands our state machine 114struct decoder_source_mgr { 115 // public fields; must be first in this struct! 116 struct jpeg_source_mgr pub; 117 118 JPEGImageReader* decoder; 119}; 120 121static unsigned readUint16(JOCTET* data, bool isBigEndian) 122{ 123 if (isBigEndian) 124 return (GETJOCTET(data[0]) << 8) | GETJOCTET(data[1]); 125 return (GETJOCTET(data[1]) << 8) | GETJOCTET(data[0]); 126} 127 128static unsigned readUint32(JOCTET* data, bool isBigEndian) 129{ 130 if (isBigEndian) 131 return (GETJOCTET(data[0]) << 24) | (GETJOCTET(data[1]) << 16) | (GETJOCTET(data[2]) << 8) | GETJOCTET(data[3]); 132 return (GETJOCTET(data[3]) << 24) | (GETJOCTET(data[2]) << 16) | (GETJOCTET(data[1]) << 8) | GETJOCTET(data[0]); 133} 134 135static bool checkExifHeader(jpeg_saved_marker_ptr marker, bool& isBigEndian, unsigned& ifdOffset) 136{ 137 // For exif data, the APP1 block is followed by 'E', 'x', 'i', 'f', '\0', 138 // then a fill byte, and then a tiff file that contains the metadata. 139 // A tiff file starts with 'I', 'I' (intel / little endian byte order) or 140 // 'M', 'M' (motorola / big endian byte order), followed by (uint16_t)42, 141 // followed by an uint32_t with the offset to the tag block, relative to the 142 // tiff file start. 143 const unsigned exifHeaderSize = 14; 144 if (!(marker->marker == exifMarker 145 && marker->data_length >= exifHeaderSize 146 && marker->data[0] == 'E' 147 && marker->data[1] == 'x' 148 && marker->data[2] == 'i' 149 && marker->data[3] == 'f' 150 && marker->data[4] == '\0' 151 // data[5] is a fill byte 152 && ((marker->data[6] == 'I' && marker->data[7] == 'I') 153 || (marker->data[6] == 'M' && marker->data[7] == 'M')))) 154 return false; 155 156 isBigEndian = marker->data[6] == 'M'; 157 if (readUint16(marker->data + 8, isBigEndian) != 42) 158 return false; 159 160 ifdOffset = readUint32(marker->data + 10, isBigEndian); 161 return true; 162} 163 164static ImageOrientation readImageOrientation(jpeg_decompress_struct* info) 165{ 166 // The JPEG decoder looks at EXIF metadata. 167 // FIXME: Possibly implement XMP and IPTC support. 168 const unsigned orientationTag = 0x112; 169 const unsigned shortType = 3; 170 for (jpeg_saved_marker_ptr marker = info->marker_list; marker; marker = marker->next) { 171 bool isBigEndian; 172 unsigned ifdOffset; 173 if (!checkExifHeader(marker, isBigEndian, ifdOffset)) 174 continue; 175 const unsigned offsetToTiffData = 6; // Account for 'Exif\0<fill byte>' header. 176 if (marker->data_length < offsetToTiffData || ifdOffset >= marker->data_length - offsetToTiffData) 177 continue; 178 ifdOffset += offsetToTiffData; 179 180 // The jpeg exif container format contains a tiff block for metadata. 181 // A tiff image file directory (ifd) consists of a uint16_t describing 182 // the number of ifd entries, followed by that many entries. 183 // When touching this code, it's useful to look at the tiff spec: 184 // http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf 185 JOCTET* ifd = marker->data + ifdOffset; 186 JOCTET* end = marker->data + marker->data_length; 187 if (end - ifd < 2) 188 continue; 189 unsigned tagCount = readUint16(ifd, isBigEndian); 190 ifd += 2; // Skip over the uint16 that was just read. 191 192 // Every ifd entry is 2 bytes of tag, 2 bytes of contents datatype, 193 // 4 bytes of number-of-elements, and 4 bytes of either offset to the 194 // tag data, or if the data is small enough, the inlined data itself. 195 const int ifdEntrySize = 12; 196 for (unsigned i = 0; i < tagCount && end - ifd >= ifdEntrySize; ++i, ifd += ifdEntrySize) { 197 unsigned tag = readUint16(ifd, isBigEndian); 198 unsigned type = readUint16(ifd + 2, isBigEndian); 199 unsigned count = readUint32(ifd + 4, isBigEndian); 200 if (tag == orientationTag && type == shortType && count == 1) 201 return ImageOrientation::fromEXIFValue(readUint16(ifd + 8, isBigEndian)); 202 } 203 } 204 205 return ImageOrientation(); 206} 207 208static ColorProfile readColorProfile(jpeg_decompress_struct* info) 209{ 210#if USE(ICCJPEG) 211 JOCTET* profile; 212 unsigned int profileLength; 213 214 if (!read_icc_profile(info, &profile, &profileLength)) 215 return ColorProfile(); 216 217 // Only accept RGB color profiles from input class devices. 218 bool ignoreProfile = false; 219 char* profileData = reinterpret_cast<char*>(profile); 220 if (profileLength < ImageDecoder::iccColorProfileHeaderLength) 221 ignoreProfile = true; 222 else if (!ImageDecoder::rgbColorProfile(profileData, profileLength)) 223 ignoreProfile = true; 224 else if (!ImageDecoder::inputDeviceColorProfile(profileData, profileLength)) 225 ignoreProfile = true; 226 227 ColorProfile colorProfile; 228 if (!ignoreProfile) 229 colorProfile.append(profileData, profileLength); 230 free(profile); 231 return colorProfile; 232#else 233 UNUSED_PARAM(info); 234 return ColorProfile(); 235#endif 236} 237 238class JPEGImageReader { 239 WTF_MAKE_FAST_ALLOCATED; 240public: 241 JPEGImageReader(JPEGImageDecoder* decoder) 242 : m_decoder(decoder) 243 , m_bufferLength(0) 244 , m_bytesToSkip(0) 245 , m_state(JPEG_HEADER) 246 , m_samples(0) 247#if USE(QCMSLIB) 248 , m_transform(0) 249#endif 250 { 251 memset(&m_info, 0, sizeof(jpeg_decompress_struct)); 252 253 // We set up the normal JPEG error routines, then override error_exit. 254 m_info.err = jpeg_std_error(&m_err.pub); 255 m_err.pub.error_exit = error_exit; 256 257 // Allocate and initialize JPEG decompression object. 258 jpeg_create_decompress(&m_info); 259 260 decoder_source_mgr* src = 0; 261 if (!m_info.src) { 262 src = (decoder_source_mgr*)fastCalloc(sizeof(decoder_source_mgr), 1); 263 if (!src) { 264 m_state = JPEG_ERROR; 265 return; 266 } 267 } 268 269 m_info.src = (jpeg_source_mgr*)src; 270 271 // Set up callback functions. 272 src->pub.init_source = init_source; 273 src->pub.fill_input_buffer = fill_input_buffer; 274 src->pub.skip_input_data = skip_input_data; 275 src->pub.resync_to_restart = jpeg_resync_to_restart; 276 src->pub.term_source = term_source; 277 src->decoder = this; 278 279#if USE(ICCJPEG) 280 // Retain ICC color profile markers for color management. 281 setup_read_icc_profile(&m_info); 282#endif 283 284 // Keep APP1 blocks, for obtaining exif data. 285 jpeg_save_markers(&m_info, exifMarker, 0xFFFF); 286 } 287 288 ~JPEGImageReader() 289 { 290 close(); 291 } 292 293 void close() 294 { 295 decoder_source_mgr* src = (decoder_source_mgr*)m_info.src; 296 if (src) 297 fastFree(src); 298 m_info.src = 0; 299 300#if USE(QCMSLIB) 301 if (m_transform) 302 qcms_transform_release(m_transform); 303 m_transform = 0; 304#endif 305 jpeg_destroy_decompress(&m_info); 306 } 307 308 void skipBytes(long numBytes) 309 { 310 decoder_source_mgr* src = (decoder_source_mgr*)m_info.src; 311 long bytesToSkip = std::min(numBytes, (long)src->pub.bytes_in_buffer); 312 src->pub.bytes_in_buffer -= (size_t)bytesToSkip; 313 src->pub.next_input_byte += bytesToSkip; 314 315 m_bytesToSkip = std::max(numBytes - bytesToSkip, static_cast<long>(0)); 316 } 317 318 bool decode(const SharedBuffer& data, bool onlySize) 319 { 320 m_decodingSizeOnly = onlySize; 321 322 unsigned newByteCount = data.size() - m_bufferLength; 323 unsigned readOffset = m_bufferLength - m_info.src->bytes_in_buffer; 324 325 m_info.src->bytes_in_buffer += newByteCount; 326 m_info.src->next_input_byte = (JOCTET*)(data.data()) + readOffset; 327 328 // If we still have bytes to skip, try to skip those now. 329 if (m_bytesToSkip) 330 skipBytes(m_bytesToSkip); 331 332 m_bufferLength = data.size(); 333 334 // We need to do the setjmp here. Otherwise bad things will happen 335 if (setjmp(m_err.setjmp_buffer)) 336 return m_decoder->setFailed(); 337 338 switch (m_state) { 339 case JPEG_HEADER: 340 // Read file parameters with jpeg_read_header(). 341 if (jpeg_read_header(&m_info, true) == JPEG_SUSPENDED) 342 return false; // I/O suspension. 343 344 switch (m_info.jpeg_color_space) { 345 case JCS_GRAYSCALE: 346 case JCS_RGB: 347 case JCS_YCbCr: 348 // libjpeg can convert GRAYSCALE and YCbCr image pixels to RGB. 349 m_info.out_color_space = rgbOutputColorSpace(); 350#if defined(TURBO_JPEG_RGB_SWIZZLE) 351 if (m_info.saw_JFIF_marker) 352 break; 353 // FIXME: Swizzle decoding does not support Adobe transform=0 354 // images (yet), so revert to using JSC_RGB in that case. 355 if (m_info.saw_Adobe_marker && !m_info.Adobe_transform) 356 m_info.out_color_space = JCS_RGB; 357#endif 358 break; 359 case JCS_CMYK: 360 case JCS_YCCK: 361 // libjpeg can convert YCCK to CMYK, but neither to RGB, so we 362 // manually convert CMKY to RGB. 363 m_info.out_color_space = JCS_CMYK; 364 break; 365 default: 366 return m_decoder->setFailed(); 367 } 368 369 m_state = JPEG_START_DECOMPRESS; 370 371 // We can fill in the size now that the header is available. 372 if (!m_decoder->setSize(m_info.image_width, m_info.image_height)) 373 return false; 374 375 m_decoder->setOrientation(readImageOrientation(info())); 376 377#if ENABLE(IMAGE_DECODER_DOWN_SAMPLING) && defined(TURBO_JPEG_RGB_SWIZZLE) 378 // There's no point swizzle decoding if image down sampling will 379 // be applied. Revert to using JSC_RGB in that case. 380 if (m_decoder->willDownSample() && turboSwizzled(m_info.out_color_space)) 381 m_info.out_color_space = JCS_RGB; 382#endif 383 // Allow color management of the decoded RGBA pixels if possible. 384 if (!m_decoder->ignoresGammaAndColorProfile()) { 385 ColorProfile rgbInputDeviceColorProfile = readColorProfile(info()); 386 if (!rgbInputDeviceColorProfile.isEmpty()) 387 m_decoder->setColorProfile(rgbInputDeviceColorProfile); 388#if USE(QCMSLIB) 389 createColorTransform(rgbInputDeviceColorProfile, colorSpaceHasAlpha(m_info.out_color_space)); 390#if defined(TURBO_JPEG_RGB_SWIZZLE) 391 // Input RGBA data to qcms. Note: restored to BGRA on output. 392 if (m_transform && m_info.out_color_space == JCS_EXT_BGRA) 393 m_info.out_color_space = JCS_EXT_RGBA; 394#endif 395#endif 396 } 397 398 // Don't allocate a giant and superfluous memory buffer when the 399 // image is a sequential JPEG. 400 m_info.buffered_image = jpeg_has_multiple_scans(&m_info); 401 402 // Used to set up image size so arrays can be allocated. 403 jpeg_calc_output_dimensions(&m_info); 404 405 // Make a one-row-high sample array that will go away when done with 406 // image. Always make it big enough to hold an RGB row. Since this 407 // uses the IJG memory manager, it must be allocated before the call 408 // to jpeg_start_compress(). 409 // FIXME: note that some output color spaces do not need the samples 410 // buffer. Remove this allocation for those color spaces. 411 m_samples = (*m_info.mem->alloc_sarray)((j_common_ptr) &m_info, JPOOL_IMAGE, m_info.output_width * 4, 1); 412 413 if (m_decodingSizeOnly) { 414 // We can stop here. Reduce our buffer length and available data. 415 m_bufferLength -= m_info.src->bytes_in_buffer; 416 m_info.src->bytes_in_buffer = 0; 417 return true; 418 } 419 // FALL THROUGH 420 421 case JPEG_START_DECOMPRESS: 422 // Set parameters for decompression. 423 // FIXME -- Should reset dct_method and dither mode for final pass 424 // of progressive JPEG. 425 m_info.dct_method = dctMethod(); 426 m_info.dither_mode = ditherMode(); 427 m_info.do_fancy_upsampling = doFancyUpsampling(); 428 m_info.enable_2pass_quant = false; 429 m_info.do_block_smoothing = true; 430 431 // Start decompressor. 432 if (!jpeg_start_decompress(&m_info)) 433 return false; // I/O suspension. 434 435 // If this is a progressive JPEG ... 436 m_state = (m_info.buffered_image) ? JPEG_DECOMPRESS_PROGRESSIVE : JPEG_DECOMPRESS_SEQUENTIAL; 437 // FALL THROUGH 438 439 case JPEG_DECOMPRESS_SEQUENTIAL: 440 if (m_state == JPEG_DECOMPRESS_SEQUENTIAL) { 441 442 if (!m_decoder->outputScanlines()) 443 return false; // I/O suspension. 444 445 // If we've completed image output... 446 ASSERT(m_info.output_scanline == m_info.output_height); 447 m_state = JPEG_DONE; 448 } 449 // FALL THROUGH 450 451 case JPEG_DECOMPRESS_PROGRESSIVE: 452 if (m_state == JPEG_DECOMPRESS_PROGRESSIVE) { 453 int status; 454 do { 455 status = jpeg_consume_input(&m_info); 456 } while ((status != JPEG_SUSPENDED) && (status != JPEG_REACHED_EOI)); 457 458 for (;;) { 459 if (!m_info.output_scanline) { 460 int scan = m_info.input_scan_number; 461 462 // If we haven't displayed anything yet 463 // (output_scan_number == 0) and we have enough data for 464 // a complete scan, force output of the last full scan. 465 if (!m_info.output_scan_number && (scan > 1) && (status != JPEG_REACHED_EOI)) 466 --scan; 467 468 if (!jpeg_start_output(&m_info, scan)) 469 return false; // I/O suspension. 470 } 471 472 if (m_info.output_scanline == 0xffffff) 473 m_info.output_scanline = 0; 474 475 if (!m_decoder->outputScanlines()) { 476 if (!m_info.output_scanline) 477 // Didn't manage to read any lines - flag so we 478 // don't call jpeg_start_output() multiple times for 479 // the same scan. 480 m_info.output_scanline = 0xffffff; 481 return false; // I/O suspension. 482 } 483 484 if (m_info.output_scanline == m_info.output_height) { 485 if (!jpeg_finish_output(&m_info)) 486 return false; // I/O suspension. 487 488 if (jpeg_input_complete(&m_info) && (m_info.input_scan_number == m_info.output_scan_number)) 489 break; 490 491 m_info.output_scanline = 0; 492 } 493 } 494 495 m_state = JPEG_DONE; 496 } 497 // FALL THROUGH 498 499 case JPEG_DONE: 500 // Finish decompression. 501 return jpeg_finish_decompress(&m_info); 502 503 case JPEG_ERROR: 504 // We can get here if the constructor failed. 505 return m_decoder->setFailed(); 506 } 507 508 return true; 509 } 510 511 jpeg_decompress_struct* info() { return &m_info; } 512 JSAMPARRAY samples() const { return m_samples; } 513 JPEGImageDecoder* decoder() { return m_decoder; } 514#if USE(QCMSLIB) 515 qcms_transform* colorTransform() const { return m_transform; } 516 517 void createColorTransform(const ColorProfile& colorProfile, bool hasAlpha) 518 { 519 if (m_transform) 520 qcms_transform_release(m_transform); 521 m_transform = 0; 522 523 if (colorProfile.isEmpty()) 524 return; 525 qcms_profile* deviceProfile = ImageDecoder::qcmsOutputDeviceProfile(); 526 if (!deviceProfile) 527 return; 528 qcms_profile* inputProfile = qcms_profile_from_memory(colorProfile.data(), colorProfile.size()); 529 if (!inputProfile) 530 return; 531 // We currently only support color profiles for RGB profiled images. 532 ASSERT(icSigRgbData == qcms_profile_get_color_space(inputProfile)); 533 qcms_data_type dataFormat = hasAlpha ? QCMS_DATA_RGBA_8 : QCMS_DATA_RGB_8; 534 // FIXME: Don't force perceptual intent if the image profile contains an intent. 535 m_transform = qcms_transform_create(inputProfile, dataFormat, deviceProfile, dataFormat, QCMS_INTENT_PERCEPTUAL); 536 qcms_profile_release(inputProfile); 537 } 538#endif 539 540private: 541 JPEGImageDecoder* m_decoder; 542 unsigned m_bufferLength; 543 int m_bytesToSkip; 544 bool m_decodingSizeOnly; 545 546 jpeg_decompress_struct m_info; 547 decoder_error_mgr m_err; 548 jstate m_state; 549 550 JSAMPARRAY m_samples; 551 552#if USE(QCMSLIB) 553 qcms_transform* m_transform; 554#endif 555}; 556 557// Override the standard error method in the IJG JPEG decoder code. 558void error_exit(j_common_ptr cinfo) 559{ 560 // Return control to the setjmp point. 561 decoder_error_mgr *err = reinterpret_cast_ptr<decoder_error_mgr *>(cinfo->err); 562 longjmp(err->setjmp_buffer, -1); 563} 564 565void init_source(j_decompress_ptr) 566{ 567} 568 569void skip_input_data(j_decompress_ptr jd, long num_bytes) 570{ 571 decoder_source_mgr *src = (decoder_source_mgr *)jd->src; 572 src->decoder->skipBytes(num_bytes); 573} 574 575boolean fill_input_buffer(j_decompress_ptr) 576{ 577 // Our decode step always sets things up properly, so if this method is ever 578 // called, then we have hit the end of the buffer. A return value of false 579 // indicates that we have no data to supply yet. 580 return false; 581} 582 583void term_source(j_decompress_ptr jd) 584{ 585 decoder_source_mgr *src = (decoder_source_mgr *)jd->src; 586 src->decoder->decoder()->jpegComplete(); 587} 588 589JPEGImageDecoder::JPEGImageDecoder(ImageSource::AlphaOption alphaOption, 590 ImageSource::GammaAndColorProfileOption gammaAndColorProfileOption) 591 : ImageDecoder(alphaOption, gammaAndColorProfileOption) 592{ 593} 594 595JPEGImageDecoder::~JPEGImageDecoder() 596{ 597} 598 599bool JPEGImageDecoder::isSizeAvailable() 600{ 601 if (!ImageDecoder::isSizeAvailable()) 602 decode(true); 603 604 return ImageDecoder::isSizeAvailable(); 605} 606 607bool JPEGImageDecoder::setSize(unsigned width, unsigned height) 608{ 609 if (!ImageDecoder::setSize(width, height)) 610 return false; 611 612 prepareScaleDataIfNecessary(); 613 return true; 614} 615 616ImageFrame* JPEGImageDecoder::frameBufferAtIndex(size_t index) 617{ 618 if (index) 619 return 0; 620 621 if (m_frameBufferCache.isEmpty()) { 622 m_frameBufferCache.resize(1); 623 m_frameBufferCache[0].setPremultiplyAlpha(m_premultiplyAlpha); 624 } 625 626 ImageFrame& frame = m_frameBufferCache[0]; 627 if (frame.status() != ImageFrame::FrameComplete) { 628 PlatformInstrumentation::willDecodeImage("JPEG"); 629 decode(false); 630 PlatformInstrumentation::didDecodeImage(); 631 } 632 return &frame; 633} 634 635bool JPEGImageDecoder::setFailed() 636{ 637 m_reader.clear(); 638 return ImageDecoder::setFailed(); 639} 640 641template <J_COLOR_SPACE colorSpace> 642void setPixel(ImageFrame& buffer, ImageFrame::PixelData* currentAddress, JSAMPARRAY samples, int column) 643{ 644 JSAMPLE* jsample = *samples + column * (colorSpace == JCS_RGB ? 3 : 4); 645 646 switch (colorSpace) { 647 case JCS_RGB: 648 buffer.setRGBA(currentAddress, jsample[0], jsample[1], jsample[2], 0xFF); 649 break; 650 case JCS_CMYK: 651 // Source is 'Inverted CMYK', output is RGB. 652 // See: http://www.easyrgb.com/math.php?MATH=M12#text12 653 // Or: http://www.ilkeratalay.com/colorspacesfaq.php#rgb 654 // From CMYK to CMY: 655 // X = X * (1 - K ) + K [for X = C, M, or Y] 656 // Thus, from Inverted CMYK to CMY is: 657 // X = (1-iX) * (1 - (1-iK)) + (1-iK) => 1 - iX*iK 658 // From CMY (0..1) to RGB (0..1): 659 // R = 1 - C => 1 - (1 - iC*iK) => iC*iK [G and B similar] 660 unsigned k = jsample[3]; 661 buffer.setRGBA(currentAddress, jsample[0] * k / 255, jsample[1] * k / 255, jsample[2] * k / 255, 0xFF); 662 break; 663 } 664} 665 666template <J_COLOR_SPACE colorSpace, bool isScaled> 667bool JPEGImageDecoder::outputScanlines(ImageFrame& buffer) 668{ 669 JSAMPARRAY samples = m_reader->samples(); 670 jpeg_decompress_struct* info = m_reader->info(); 671 int width = isScaled ? m_scaledColumns.size() : info->output_width; 672 673 while (info->output_scanline < info->output_height) { 674 // jpeg_read_scanlines will increase the scanline counter, so we 675 // save the scanline before calling it. 676 int sourceY = info->output_scanline; 677 /* Request one scanline. Returns 0 or 1 scanlines. */ 678 if (jpeg_read_scanlines(info, samples, 1) != 1) 679 return false; 680 681 int destY = scaledY(sourceY); 682 if (destY < 0) 683 continue; 684 685#if USE(QCMSLIB) 686 if (m_reader->colorTransform() && colorSpace == JCS_RGB) 687 qcms_transform_data(m_reader->colorTransform(), *samples, *samples, info->output_width); 688#endif 689 690 ImageFrame::PixelData* currentAddress = buffer.getAddr(0, destY); 691 for (int x = 0; x < width; ++x) { 692 setPixel<colorSpace>(buffer, currentAddress, samples, isScaled ? m_scaledColumns[x] : x); 693 ++currentAddress; 694 } 695 } 696 return true; 697} 698 699template <J_COLOR_SPACE colorSpace> 700bool JPEGImageDecoder::outputScanlines(ImageFrame& buffer) 701{ 702 return m_scaled ? outputScanlines<colorSpace, true>(buffer) : outputScanlines<colorSpace, false>(buffer); 703} 704 705bool JPEGImageDecoder::outputScanlines() 706{ 707 if (m_frameBufferCache.isEmpty()) 708 return false; 709 710 // Initialize the framebuffer if needed. 711 ImageFrame& buffer = m_frameBufferCache[0]; 712 if (buffer.status() == ImageFrame::FrameEmpty) { 713 if (!buffer.setSize(scaledSize().width(), scaledSize().height())) 714 return setFailed(); 715 buffer.setStatus(ImageFrame::FramePartial); 716 // The buffer is transparent outside the decoded area while the image is 717 // loading. The completed image will be marked fully opaque in jpegComplete(). 718 buffer.setHasAlpha(true); 719 buffer.setColorProfile(m_colorProfile); 720 721 // For JPEGs, the frame always fills the entire image. 722 buffer.setOriginalFrameRect(IntRect(IntPoint(), size())); 723 } 724 725 jpeg_decompress_struct* info = m_reader->info(); 726 727#if defined(TURBO_JPEG_RGB_SWIZZLE) 728 if (!m_scaled && turboSwizzled(info->out_color_space)) { 729 while (info->output_scanline < info->output_height) { 730 unsigned char* row = reinterpret_cast<unsigned char*>(buffer.getAddr(0, info->output_scanline)); 731 if (jpeg_read_scanlines(info, &row, 1) != 1) 732 return false; 733#if USE(QCMSLIB) 734 if (qcms_transform* transform = m_reader->colorTransform()) 735 qcms_transform_data_type(transform, row, row, info->output_width, rgbOutputColorSpace() == JCS_EXT_BGRA ? QCMS_OUTPUT_BGRX : QCMS_OUTPUT_RGBX); 736#endif 737 } 738 return true; 739 } 740#endif 741 742 switch (info->out_color_space) { 743 // The code inside outputScanlines<int, bool> will be executed 744 // for each pixel, so we want to avoid any extra comparisons there. 745 // That is why we use template and template specializations here so 746 // the proper code will be generated at compile time. 747 case JCS_RGB: 748 return outputScanlines<JCS_RGB>(buffer); 749 case JCS_CMYK: 750 return outputScanlines<JCS_CMYK>(buffer); 751 default: 752 ASSERT_NOT_REACHED(); 753 } 754 755 return setFailed(); 756} 757 758void JPEGImageDecoder::jpegComplete() 759{ 760 if (m_frameBufferCache.isEmpty()) 761 return; 762 763 // Hand back an appropriately sized buffer, even if the image ended up being 764 // empty. 765 ImageFrame& buffer = m_frameBufferCache[0]; 766 buffer.setHasAlpha(false); 767 buffer.setStatus(ImageFrame::FrameComplete); 768} 769 770void JPEGImageDecoder::decode(bool onlySize) 771{ 772 if (failed()) 773 return; 774 775 if (!m_reader) 776 m_reader = adoptPtr(new JPEGImageReader(this)); 777 778 // If we couldn't decode the image but we've received all the data, decoding 779 // has failed. 780 if (!m_reader->decode(*m_data, onlySize) && isAllDataReceived()) 781 setFailed(); 782 // If we're done decoding the image, we don't need the JPEGImageReader 783 // anymore. (If we failed, |m_reader| has already been cleared.) 784 else if (!m_frameBufferCache.isEmpty() && (m_frameBufferCache[0].status() == ImageFrame::FrameComplete)) 785 m_reader.clear(); 786} 787 788} 789