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 (at) 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 "core/platform/image-decoders/jpeg/JPEGImageDecoder.h" 42 43 #include "core/platform/PlatformInstrumentation.h" 44 #include "wtf/CPU.h" 45 #include "wtf/PassOwnPtr.h" 46 47 extern "C" { 48 #include <stdio.h> // jpeglib.h needs stdio FILE. 49 #include "jpeglib.h" 50 #if USE(ICCJPEG) 51 #include "iccjpeg.h" 52 #endif 53 #if USE(QCMSLIB) 54 #include "qcms.h" 55 #endif 56 #include <setjmp.h> 57 } 58 59 #if CPU(BIG_ENDIAN) || CPU(MIDDLE_ENDIAN) 60 #define ASSUME_LITTLE_ENDIAN 0 61 #else 62 #define ASSUME_LITTLE_ENDIAN 1 63 #endif 64 65 #if defined(JCS_ALPHA_EXTENSIONS) && ASSUME_LITTLE_ENDIAN 66 #define TURBO_JPEG_RGB_SWIZZLE 67 #if !SK_R32_SHIFT && SK_G32_SHIFT == 8 && SK_B32_SHIFT == 16 68 inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_EXT_RGBA; } 69 #else 70 inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_EXT_BGRA; } 71 #endif 72 inline bool turboSwizzled(J_COLOR_SPACE colorSpace) { return colorSpace == JCS_EXT_RGBA || colorSpace == JCS_EXT_BGRA; } 73 inline bool colorSpaceHasAlpha(J_COLOR_SPACE colorSpace) { return turboSwizzled(colorSpace); } 74 #else 75 inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_RGB; } 76 inline bool colorSpaceHasAlpha(J_COLOR_SPACE) { return false; } 77 #endif 78 79 #if USE(LOW_QUALITY_IMAGE_NO_JPEG_DITHERING) 80 inline J_DCT_METHOD dctMethod() { return JDCT_IFAST; } 81 inline J_DITHER_MODE ditherMode() { return JDITHER_NONE; } 82 #else 83 inline J_DCT_METHOD dctMethod() { return JDCT_ISLOW; } 84 inline J_DITHER_MODE ditherMode() { return JDITHER_FS; } 85 #endif 86 87 #if USE(LOW_QUALITY_IMAGE_NO_JPEG_FANCY_UPSAMPLING) 88 inline bool doFancyUpsampling() { return false; } 89 #else 90 inline bool doFancyUpsampling() { return true; } 91 #endif 92 93 const int exifMarker = JPEG_APP0 + 1; 94 95 namespace WebCore { 96 97 struct decoder_error_mgr { 98 struct jpeg_error_mgr pub; // "public" fields for IJG library 99 jmp_buf setjmp_buffer; // For handling catastropic errors 100 }; 101 102 enum jstate { 103 JPEG_HEADER, // Reading JFIF headers 104 JPEG_START_DECOMPRESS, 105 JPEG_DECOMPRESS_PROGRESSIVE, // Output progressive pixels 106 JPEG_DECOMPRESS_SEQUENTIAL, // Output sequential pixels 107 JPEG_DONE, 108 JPEG_ERROR 109 }; 110 111 void init_source(j_decompress_ptr jd); 112 boolean fill_input_buffer(j_decompress_ptr jd); 113 void skip_input_data(j_decompress_ptr jd, long num_bytes); 114 void term_source(j_decompress_ptr jd); 115 void error_exit(j_common_ptr cinfo); 116 117 // Implementation of a JPEG src object that understands our state machine 118 struct decoder_source_mgr { 119 // public fields; must be first in this struct! 120 struct jpeg_source_mgr pub; 121 122 JPEGImageReader* decoder; 123 }; 124 125 static unsigned readUint16(JOCTET* data, bool isBigEndian) 126 { 127 if (isBigEndian) 128 return (GETJOCTET(data[0]) << 8) | GETJOCTET(data[1]); 129 return (GETJOCTET(data[1]) << 8) | GETJOCTET(data[0]); 130 } 131 132 static unsigned readUint32(JOCTET* data, bool isBigEndian) 133 { 134 if (isBigEndian) 135 return (GETJOCTET(data[0]) << 24) | (GETJOCTET(data[1]) << 16) | (GETJOCTET(data[2]) << 8) | GETJOCTET(data[3]); 136 return (GETJOCTET(data[3]) << 24) | (GETJOCTET(data[2]) << 16) | (GETJOCTET(data[1]) << 8) | GETJOCTET(data[0]); 137 } 138 139 static bool checkExifHeader(jpeg_saved_marker_ptr marker, bool& isBigEndian, unsigned& ifdOffset) 140 { 141 // For exif data, the APP1 block is followed by 'E', 'x', 'i', 'f', '\0', 142 // then a fill byte, and then a tiff file that contains the metadata. 143 // A tiff file starts with 'I', 'I' (intel / little endian byte order) or 144 // 'M', 'M' (motorola / big endian byte order), followed by (uint16_t)42, 145 // followed by an uint32_t with the offset to the tag block, relative to the 146 // tiff file start. 147 const unsigned exifHeaderSize = 14; 148 if (!(marker->marker == exifMarker 149 && marker->data_length >= exifHeaderSize 150 && marker->data[0] == 'E' 151 && marker->data[1] == 'x' 152 && marker->data[2] == 'i' 153 && marker->data[3] == 'f' 154 && marker->data[4] == '\0' 155 // data[5] is a fill byte 156 && ((marker->data[6] == 'I' && marker->data[7] == 'I') 157 || (marker->data[6] == 'M' && marker->data[7] == 'M')))) 158 return false; 159 160 isBigEndian = marker->data[6] == 'M'; 161 if (readUint16(marker->data + 8, isBigEndian) != 42) 162 return false; 163 164 ifdOffset = readUint32(marker->data + 10, isBigEndian); 165 return true; 166 } 167 168 static ImageOrientation readImageOrientation(jpeg_decompress_struct* info) 169 { 170 // The JPEG decoder looks at EXIF metadata. 171 // FIXME: Possibly implement XMP and IPTC support. 172 const unsigned orientationTag = 0x112; 173 const unsigned shortType = 3; 174 for (jpeg_saved_marker_ptr marker = info->marker_list; marker; marker = marker->next) { 175 bool isBigEndian; 176 unsigned ifdOffset; 177 if (!checkExifHeader(marker, isBigEndian, ifdOffset)) 178 continue; 179 const unsigned offsetToTiffData = 6; // Account for 'Exif\0<fill byte>' header. 180 if (marker->data_length < offsetToTiffData || ifdOffset >= marker->data_length - offsetToTiffData) 181 continue; 182 ifdOffset += offsetToTiffData; 183 184 // The jpeg exif container format contains a tiff block for metadata. 185 // A tiff image file directory (ifd) consists of a uint16_t describing 186 // the number of ifd entries, followed by that many entries. 187 // When touching this code, it's useful to look at the tiff spec: 188 // http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf 189 JOCTET* ifd = marker->data + ifdOffset; 190 JOCTET* end = marker->data + marker->data_length; 191 if (end - ifd < 2) 192 continue; 193 unsigned tagCount = readUint16(ifd, isBigEndian); 194 ifd += 2; // Skip over the uint16 that was just read. 195 196 // Every ifd entry is 2 bytes of tag, 2 bytes of contents datatype, 197 // 4 bytes of number-of-elements, and 4 bytes of either offset to the 198 // tag data, or if the data is small enough, the inlined data itself. 199 const int ifdEntrySize = 12; 200 for (unsigned i = 0; i < tagCount && end - ifd >= ifdEntrySize; ++i, ifd += ifdEntrySize) { 201 unsigned tag = readUint16(ifd, isBigEndian); 202 unsigned type = readUint16(ifd + 2, isBigEndian); 203 unsigned count = readUint32(ifd + 4, isBigEndian); 204 if (tag == orientationTag && type == shortType && count == 1) 205 return ImageOrientation::fromEXIFValue(readUint16(ifd + 8, isBigEndian)); 206 } 207 } 208 209 return ImageOrientation(); 210 } 211 212 static void readColorProfile(jpeg_decompress_struct* info, ColorProfile& colorProfile) 213 { 214 #if USE(ICCJPEG) 215 JOCTET* profile; 216 unsigned int profileLength; 217 218 if (!read_icc_profile(info, &profile, &profileLength)) 219 return; 220 221 // Only accept RGB color profiles from input class devices. 222 bool ignoreProfile = false; 223 char* profileData = reinterpret_cast<char*>(profile); 224 if (profileLength < ImageDecoder::iccColorProfileHeaderLength) 225 ignoreProfile = true; 226 else if (!ImageDecoder::rgbColorProfile(profileData, profileLength)) 227 ignoreProfile = true; 228 else if (!ImageDecoder::inputDeviceColorProfile(profileData, profileLength)) 229 ignoreProfile = true; 230 231 ASSERT(colorProfile.isEmpty()); 232 if (!ignoreProfile) 233 colorProfile.append(profileData, profileLength); 234 free(profile); 235 #else 236 UNUSED_PARAM(info); 237 UNUSED_PARAM(colorProfile); 238 #endif 239 } 240 241 class JPEGImageReader { 242 WTF_MAKE_FAST_ALLOCATED; 243 public: 244 JPEGImageReader(JPEGImageDecoder* decoder) 245 : m_decoder(decoder) 246 , m_bufferLength(0) 247 , m_bytesToSkip(0) 248 , m_state(JPEG_HEADER) 249 , m_samples(0) 250 #if USE(QCMSLIB) 251 , m_transform(0) 252 #endif 253 { 254 memset(&m_info, 0, sizeof(jpeg_decompress_struct)); 255 256 // We set up the normal JPEG error routines, then override error_exit. 257 m_info.err = jpeg_std_error(&m_err.pub); 258 m_err.pub.error_exit = error_exit; 259 260 // Allocate and initialize JPEG decompression object. 261 jpeg_create_decompress(&m_info); 262 263 decoder_source_mgr* src = 0; 264 if (!m_info.src) { 265 src = (decoder_source_mgr*)fastCalloc(sizeof(decoder_source_mgr), 1); 266 if (!src) { 267 m_state = JPEG_ERROR; 268 return; 269 } 270 } 271 272 m_info.src = (jpeg_source_mgr*)src; 273 274 // Set up callback functions. 275 src->pub.init_source = init_source; 276 src->pub.fill_input_buffer = fill_input_buffer; 277 src->pub.skip_input_data = skip_input_data; 278 src->pub.resync_to_restart = jpeg_resync_to_restart; 279 src->pub.term_source = term_source; 280 src->decoder = this; 281 282 #if USE(ICCJPEG) 283 // Retain ICC color profile markers for color management. 284 setup_read_icc_profile(&m_info); 285 #endif 286 287 // Keep APP1 blocks, for obtaining exif data. 288 jpeg_save_markers(&m_info, exifMarker, 0xFFFF); 289 } 290 291 ~JPEGImageReader() 292 { 293 close(); 294 } 295 296 void close() 297 { 298 decoder_source_mgr* src = (decoder_source_mgr*)m_info.src; 299 if (src) 300 fastFree(src); 301 m_info.src = 0; 302 303 #if USE(QCMSLIB) 304 if (m_transform) 305 qcms_transform_release(m_transform); 306 m_transform = 0; 307 #endif 308 jpeg_destroy_decompress(&m_info); 309 } 310 311 void skipBytes(long numBytes) 312 { 313 decoder_source_mgr* src = (decoder_source_mgr*)m_info.src; 314 long bytesToSkip = std::min(numBytes, (long)src->pub.bytes_in_buffer); 315 src->pub.bytes_in_buffer -= (size_t)bytesToSkip; 316 src->pub.next_input_byte += bytesToSkip; 317 318 m_bytesToSkip = std::max(numBytes - bytesToSkip, static_cast<long>(0)); 319 } 320 321 bool decode(const SharedBuffer& data, bool onlySize) 322 { 323 m_decodingSizeOnly = onlySize; 324 325 unsigned newByteCount = data.size() - m_bufferLength; 326 unsigned readOffset = m_bufferLength - m_info.src->bytes_in_buffer; 327 328 m_info.src->bytes_in_buffer += newByteCount; 329 m_info.src->next_input_byte = (JOCTET*)(data.data()) + readOffset; 330 331 // If we still have bytes to skip, try to skip those now. 332 if (m_bytesToSkip) 333 skipBytes(m_bytesToSkip); 334 335 m_bufferLength = data.size(); 336 337 // We need to do the setjmp here. Otherwise bad things will happen 338 if (setjmp(m_err.setjmp_buffer)) 339 return m_decoder->setFailed(); 340 341 switch (m_state) { 342 case JPEG_HEADER: 343 // Read file parameters with jpeg_read_header(). 344 if (jpeg_read_header(&m_info, true) == JPEG_SUSPENDED) 345 return false; // I/O suspension. 346 347 switch (m_info.jpeg_color_space) { 348 case JCS_GRAYSCALE: 349 case JCS_RGB: 350 case JCS_YCbCr: 351 // libjpeg can convert GRAYSCALE and YCbCr image pixels to RGB. 352 m_info.out_color_space = rgbOutputColorSpace(); 353 #if defined(TURBO_JPEG_RGB_SWIZZLE) 354 if (m_info.saw_JFIF_marker) 355 break; 356 // FIXME: Swizzle decoding does not support Adobe transform=0 357 // images (yet), so revert to using JSC_RGB in that case. 358 if (m_info.saw_Adobe_marker && !m_info.Adobe_transform) 359 m_info.out_color_space = JCS_RGB; 360 #endif 361 break; 362 case JCS_CMYK: 363 case JCS_YCCK: 364 // libjpeg can convert YCCK to CMYK, but neither to RGB, so we 365 // manually convert CMKY to RGB. 366 m_info.out_color_space = JCS_CMYK; 367 break; 368 default: 369 return m_decoder->setFailed(); 370 } 371 372 m_state = JPEG_START_DECOMPRESS; 373 374 // We can fill in the size now that the header is available. 375 if (!m_decoder->setSize(m_info.image_width, m_info.image_height)) 376 return false; 377 378 m_decoder->setOrientation(readImageOrientation(info())); 379 380 #if USE(QCMSLIB) 381 // Allow color management of the decoded RGBA pixels if possible. 382 if (!m_decoder->ignoresGammaAndColorProfile()) { 383 ColorProfile colorProfile; 384 readColorProfile(info(), colorProfile); 385 createColorTransform(colorProfile, colorSpaceHasAlpha(m_info.out_color_space)); 386 #if defined(TURBO_JPEG_RGB_SWIZZLE) 387 // Input RGBA data to qcms. Note: restored to BGRA on output. 388 if (m_transform && m_info.out_color_space == JCS_EXT_BGRA) 389 m_info.out_color_space = JCS_EXT_RGBA; 390 #endif 391 } 392 #endif 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(); 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 540 541 private: 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. 559 void 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 } 565 566 void init_source(j_decompress_ptr) 567 { 568 } 569 570 void 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 } 575 576 boolean 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 } 583 584 void term_source(j_decompress_ptr jd) 585 { 586 decoder_source_mgr *src = (decoder_source_mgr *)jd->src; 587 src->decoder->decoder()->jpegComplete(); 588 } 589 590 JPEGImageDecoder::JPEGImageDecoder(ImageSource::AlphaOption alphaOption, 591 ImageSource::GammaAndColorProfileOption gammaAndColorProfileOption) 592 : ImageDecoder(alphaOption, gammaAndColorProfileOption) 593 { 594 } 595 596 JPEGImageDecoder::~JPEGImageDecoder() 597 { 598 } 599 600 bool JPEGImageDecoder::isSizeAvailable() 601 { 602 if (!ImageDecoder::isSizeAvailable()) 603 decode(true); 604 605 return ImageDecoder::isSizeAvailable(); 606 } 607 608 ImageFrame* JPEGImageDecoder::frameBufferAtIndex(size_t index) 609 { 610 if (index) 611 return 0; 612 613 if (m_frameBufferCache.isEmpty()) { 614 m_frameBufferCache.resize(1); 615 m_frameBufferCache[0].setPremultiplyAlpha(m_premultiplyAlpha); 616 } 617 618 ImageFrame& frame = m_frameBufferCache[0]; 619 if (frame.status() != ImageFrame::FrameComplete) { 620 PlatformInstrumentation::willDecodeImage("JPEG"); 621 decode(false); 622 PlatformInstrumentation::didDecodeImage(); 623 } 624 return &frame; 625 } 626 627 bool JPEGImageDecoder::setFailed() 628 { 629 m_reader.clear(); 630 return ImageDecoder::setFailed(); 631 } 632 633 template <J_COLOR_SPACE colorSpace> void setPixel(ImageFrame& buffer, ImageFrame::PixelData* pixel, JSAMPARRAY samples, int column) 634 { 635 JSAMPLE* jsample = *samples + column * (colorSpace == JCS_RGB ? 3 : 4); 636 637 switch (colorSpace) { 638 case JCS_RGB: 639 buffer.setRGBARaw(pixel, jsample[0], jsample[1], jsample[2], 255); 640 break; 641 case JCS_CMYK: 642 // Source is 'Inverted CMYK', output is RGB. 643 // See: http://www.easyrgb.com/math.php?MATH=M12#text12 644 // Or: http://www.ilkeratalay.com/colorspacesfaq.php#rgb 645 // From CMYK to CMY: 646 // X = X * (1 - K ) + K [for X = C, M, or Y] 647 // Thus, from Inverted CMYK to CMY is: 648 // X = (1-iX) * (1 - (1-iK)) + (1-iK) => 1 - iX*iK 649 // From CMY (0..1) to RGB (0..1): 650 // R = 1 - C => 1 - (1 - iC*iK) => iC*iK [G and B similar] 651 unsigned k = jsample[3]; 652 buffer.setRGBARaw(pixel, jsample[0] * k / 255, jsample[1] * k / 255, jsample[2] * k / 255, 255); 653 break; 654 } 655 } 656 657 template <J_COLOR_SPACE colorSpace> bool outputRows(JPEGImageReader* reader, ImageFrame& buffer) 658 { 659 JSAMPARRAY samples = reader->samples(); 660 jpeg_decompress_struct* info = reader->info(); 661 int width = info->output_width; 662 663 while (info->output_scanline < info->output_height) { 664 // jpeg_read_scanlines will increase the scanline counter, so we 665 // save the scanline before calling it. 666 int y = info->output_scanline; 667 // Request one scanline: returns 0 or 1 scanlines. 668 if (jpeg_read_scanlines(info, samples, 1) != 1) 669 return false; 670 #if USE(QCMSLIB) 671 if (reader->colorTransform() && colorSpace == JCS_RGB) 672 qcms_transform_data(reader->colorTransform(), *samples, *samples, width); 673 #endif 674 ImageFrame::PixelData* pixel = buffer.getAddr(0, y); 675 for (int x = 0; x < width; ++pixel, ++x) 676 setPixel<colorSpace>(buffer, pixel, samples, x); 677 } 678 679 return true; 680 } 681 682 bool JPEGImageDecoder::outputScanlines() 683 { 684 if (m_frameBufferCache.isEmpty()) 685 return false; 686 687 // Initialize the framebuffer if needed. 688 ImageFrame& buffer = m_frameBufferCache[0]; 689 if (buffer.status() == ImageFrame::FrameEmpty) { 690 if (!buffer.setSize(size().width(), size().height())) 691 return setFailed(); 692 buffer.setStatus(ImageFrame::FramePartial); 693 // The buffer is transparent outside the decoded area while the image is 694 // loading. The completed image will be marked fully opaque in jpegComplete(). 695 buffer.setHasAlpha(true); 696 697 // For JPEGs, the frame always fills the entire image. 698 buffer.setOriginalFrameRect(IntRect(IntPoint(), size())); 699 } 700 701 jpeg_decompress_struct* info = m_reader->info(); 702 703 #if defined(TURBO_JPEG_RGB_SWIZZLE) 704 if (turboSwizzled(info->out_color_space)) { 705 while (info->output_scanline < info->output_height) { 706 unsigned char* row = reinterpret_cast<unsigned char*>(buffer.getAddr(0, info->output_scanline)); 707 if (jpeg_read_scanlines(info, &row, 1) != 1) 708 return false; 709 #if USE(QCMSLIB) 710 if (qcms_transform* transform = m_reader->colorTransform()) 711 qcms_transform_data_type(transform, row, row, info->output_width, rgbOutputColorSpace() == JCS_EXT_BGRA ? QCMS_OUTPUT_BGRX : QCMS_OUTPUT_RGBX); 712 #endif 713 } 714 return true; 715 } 716 #endif 717 718 switch (info->out_color_space) { 719 case JCS_RGB: 720 return outputRows<JCS_RGB>(m_reader.get(), buffer); 721 case JCS_CMYK: 722 return outputRows<JCS_CMYK>(m_reader.get(), buffer); 723 default: 724 ASSERT_NOT_REACHED(); 725 } 726 727 return setFailed(); 728 } 729 730 void JPEGImageDecoder::jpegComplete() 731 { 732 if (m_frameBufferCache.isEmpty()) 733 return; 734 735 // Hand back an appropriately sized buffer, even if the image ended up being 736 // empty. 737 ImageFrame& buffer = m_frameBufferCache[0]; 738 buffer.setHasAlpha(false); 739 buffer.setStatus(ImageFrame::FrameComplete); 740 } 741 742 void JPEGImageDecoder::decode(bool onlySize) 743 { 744 if (failed()) 745 return; 746 747 if (!m_reader) 748 m_reader = adoptPtr(new JPEGImageReader(this)); 749 750 // If we couldn't decode the image but we've received all the data, decoding 751 // has failed. 752 if (!m_reader->decode(*m_data, onlySize) && isAllDataReceived()) 753 setFailed(); 754 // If we're done decoding the image, we don't need the JPEGImageReader 755 // anymore. (If we failed, |m_reader| has already been cleared.) 756 else if (!m_frameBufferCache.isEmpty() && (m_frameBufferCache[0].status() == ImageFrame::FrameComplete)) 757 m_reader.clear(); 758 } 759 760 } 761