2 * Copyright (C) 2006 Apple Computer, Inc.
4 * Portions are Copyright (C) 2001-6 mozilla.org
7 * Stuart Parmenter <stuart@mozilla.com>
9 * Copyright (C) 2007-2009 Torch Mobile, Inc.
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.
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.
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
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
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36 * If you do not delete the provisions above, a recipient may use your
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41 #include "platform/image-decoders/jpeg/JPEGImageDecoder.h"
43 #include "platform/PlatformInstrumentation.h"
44 #include "wtf/PassOwnPtr.h"
45 #include "wtf/dtoa/utils.h"
48 #include <stdio.h> // jpeglib.h needs stdio FILE.
59 #if CPU(BIG_ENDIAN) || CPU(MIDDLE_ENDIAN)
60 #error Blink assumes a little-endian target.
63 #if defined(JCS_ALPHA_EXTENSIONS)
64 #define TURBO_JPEG_RGB_SWIZZLE
65 #if SK_B32_SHIFT // Output little-endian RGBA pixels (Android).
66 inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_EXT_RGBA; }
67 #else // Output little-endian BGRA pixels.
68 inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_EXT_BGRA; }
70 inline bool turboSwizzled(J_COLOR_SPACE colorSpace) { return colorSpace == JCS_EXT_RGBA || colorSpace == JCS_EXT_BGRA; }
71 inline bool colorSpaceHasAlpha(J_COLOR_SPACE colorSpace) { return turboSwizzled(colorSpace); }
73 inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_RGB; }
74 inline bool colorSpaceHasAlpha(J_COLOR_SPACE) { return false; }
77 #if USE(LOW_QUALITY_IMAGE_NO_JPEG_DITHERING)
78 inline J_DCT_METHOD dctMethod() { return JDCT_IFAST; }
79 inline J_DITHER_MODE ditherMode() { return JDITHER_NONE; }
81 inline J_DCT_METHOD dctMethod() { return JDCT_ISLOW; }
82 inline J_DITHER_MODE ditherMode() { return JDITHER_FS; }
85 #if USE(LOW_QUALITY_IMAGE_NO_JPEG_FANCY_UPSAMPLING)
86 inline bool doFancyUpsampling() { return false; }
88 inline bool doFancyUpsampling() { return true; }
93 const int exifMarker = JPEG_APP0 + 1;
95 // JPEG only supports a denominator of 8.
96 const unsigned scaleDenominator = 8;
102 struct decoder_error_mgr {
103 struct jpeg_error_mgr pub; // "public" fields for IJG library
104 jmp_buf setjmp_buffer; // For handling catastropic errors
108 JPEG_HEADER, // Reading JFIF headers
109 JPEG_START_DECOMPRESS,
110 JPEG_DECOMPRESS_PROGRESSIVE, // Output progressive pixels
111 JPEG_DECOMPRESS_SEQUENTIAL, // Output sequential pixels
116 enum yuv_subsampling {
126 void init_source(j_decompress_ptr jd);
127 boolean fill_input_buffer(j_decompress_ptr jd);
128 void skip_input_data(j_decompress_ptr jd, long num_bytes);
129 void term_source(j_decompress_ptr jd);
130 void error_exit(j_common_ptr cinfo);
132 // Implementation of a JPEG src object that understands our state machine
133 struct decoder_source_mgr {
134 // public fields; must be first in this struct!
135 struct jpeg_source_mgr pub;
137 JPEGImageReader* decoder;
140 static unsigned readUint16(JOCTET* data, bool isBigEndian)
143 return (GETJOCTET(data[0]) << 8) | GETJOCTET(data[1]);
144 return (GETJOCTET(data[1]) << 8) | GETJOCTET(data[0]);
147 static unsigned readUint32(JOCTET* data, bool isBigEndian)
150 return (GETJOCTET(data[0]) << 24) | (GETJOCTET(data[1]) << 16) | (GETJOCTET(data[2]) << 8) | GETJOCTET(data[3]);
151 return (GETJOCTET(data[3]) << 24) | (GETJOCTET(data[2]) << 16) | (GETJOCTET(data[1]) << 8) | GETJOCTET(data[0]);
154 static bool checkExifHeader(jpeg_saved_marker_ptr marker, bool& isBigEndian, unsigned& ifdOffset)
156 // For exif data, the APP1 block is followed by 'E', 'x', 'i', 'f', '\0',
157 // then a fill byte, and then a tiff file that contains the metadata.
158 // A tiff file starts with 'I', 'I' (intel / little endian byte order) or
159 // 'M', 'M' (motorola / big endian byte order), followed by (uint16_t)42,
160 // followed by an uint32_t with the offset to the tag block, relative to the
162 const unsigned exifHeaderSize = 14;
163 if (!(marker->marker == exifMarker
164 && marker->data_length >= exifHeaderSize
165 && marker->data[0] == 'E'
166 && marker->data[1] == 'x'
167 && marker->data[2] == 'i'
168 && marker->data[3] == 'f'
169 && marker->data[4] == '\0'
170 // data[5] is a fill byte
171 && ((marker->data[6] == 'I' && marker->data[7] == 'I')
172 || (marker->data[6] == 'M' && marker->data[7] == 'M'))))
175 isBigEndian = marker->data[6] == 'M';
176 if (readUint16(marker->data + 8, isBigEndian) != 42)
179 ifdOffset = readUint32(marker->data + 10, isBigEndian);
183 static ImageOrientation readImageOrientation(jpeg_decompress_struct* info)
185 // The JPEG decoder looks at EXIF metadata.
186 // FIXME: Possibly implement XMP and IPTC support.
187 const unsigned orientationTag = 0x112;
188 const unsigned shortType = 3;
189 for (jpeg_saved_marker_ptr marker = info->marker_list; marker; marker = marker->next) {
192 if (!checkExifHeader(marker, isBigEndian, ifdOffset))
194 const unsigned offsetToTiffData = 6; // Account for 'Exif\0<fill byte>' header.
195 if (marker->data_length < offsetToTiffData || ifdOffset >= marker->data_length - offsetToTiffData)
197 ifdOffset += offsetToTiffData;
199 // The jpeg exif container format contains a tiff block for metadata.
200 // A tiff image file directory (ifd) consists of a uint16_t describing
201 // the number of ifd entries, followed by that many entries.
202 // When touching this code, it's useful to look at the tiff spec:
203 // http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf
204 JOCTET* ifd = marker->data + ifdOffset;
205 JOCTET* end = marker->data + marker->data_length;
208 unsigned tagCount = readUint16(ifd, isBigEndian);
209 ifd += 2; // Skip over the uint16 that was just read.
211 // Every ifd entry is 2 bytes of tag, 2 bytes of contents datatype,
212 // 4 bytes of number-of-elements, and 4 bytes of either offset to the
213 // tag data, or if the data is small enough, the inlined data itself.
214 const int ifdEntrySize = 12;
215 for (unsigned i = 0; i < tagCount && end - ifd >= ifdEntrySize; ++i, ifd += ifdEntrySize) {
216 unsigned tag = readUint16(ifd, isBigEndian);
217 unsigned type = readUint16(ifd + 2, isBigEndian);
218 unsigned count = readUint32(ifd + 4, isBigEndian);
219 if (tag == orientationTag && type == shortType && count == 1)
220 return ImageOrientation::fromEXIFValue(readUint16(ifd + 8, isBigEndian));
224 return ImageOrientation();
228 static void readColorProfile(jpeg_decompress_struct* info, ColorProfile& colorProfile)
232 unsigned profileLength;
234 if (!read_icc_profile(info, &profile, &profileLength))
237 // Only accept RGB color profiles from input class devices.
238 bool ignoreProfile = false;
239 char* profileData = reinterpret_cast<char*>(profile);
240 if (profileLength < ImageDecoder::iccColorProfileHeaderLength)
241 ignoreProfile = true;
242 else if (!ImageDecoder::rgbColorProfile(profileData, profileLength))
243 ignoreProfile = true;
244 else if (!ImageDecoder::inputDeviceColorProfile(profileData, profileLength))
245 ignoreProfile = true;
247 ASSERT(colorProfile.isEmpty());
249 colorProfile.append(profileData, profileLength);
255 static IntSize computeYUVSize(const jpeg_decompress_struct* info, int component, ImageDecoder::SizeType sizeType)
257 if (sizeType == ImageDecoder::SizeForMemoryAllocation) {
258 return IntSize(info->cur_comp_info[component]->width_in_blocks * DCTSIZE, info->cur_comp_info[component]->height_in_blocks * DCTSIZE);
260 return IntSize(info->cur_comp_info[component]->downsampled_width, info->cur_comp_info[component]->downsampled_height);
263 static yuv_subsampling yuvSubsampling(const jpeg_decompress_struct& info)
266 && (info.num_components == 3)
267 && (info.comps_in_scan >= info.num_components)
268 && (info.scale_denom <= 8)
269 && (info.cur_comp_info[0])
270 && (info.cur_comp_info[1])
271 && (info.cur_comp_info[2])
272 && (info.cur_comp_info[1]->h_samp_factor == 1)
273 && (info.cur_comp_info[1]->v_samp_factor == 1)
274 && (info.cur_comp_info[2]->h_samp_factor == 1)
275 && (info.cur_comp_info[2]->v_samp_factor == 1)) {
276 int h = info.cur_comp_info[0]->h_samp_factor;
277 int v = info.cur_comp_info[0]->v_samp_factor;
278 // 4:4:4 : (h == 1) && (v == 1)
279 // 4:4:0 : (h == 1) && (v == 2)
280 // 4:2:2 : (h == 2) && (v == 1)
281 // 4:2:0 : (h == 2) && (v == 2)
282 // 4:1:1 : (h == 4) && (v == 1)
283 // 4:1:0 : (h == 4) && (v == 2)
312 class JPEGImageReader {
313 WTF_MAKE_FAST_ALLOCATED;
315 JPEGImageReader(JPEGImageDecoder* decoder)
319 , m_state(JPEG_HEADER)
325 memset(&m_info, 0, sizeof(jpeg_decompress_struct));
327 // We set up the normal JPEG error routines, then override error_exit.
328 m_info.err = jpeg_std_error(&m_err.pub);
329 m_err.pub.error_exit = error_exit;
331 // Allocate and initialize JPEG decompression object.
332 jpeg_create_decompress(&m_info);
334 decoder_source_mgr* src = 0;
336 src = (decoder_source_mgr*)fastZeroedMalloc(sizeof(decoder_source_mgr));
338 m_state = JPEG_ERROR;
343 m_info.src = (jpeg_source_mgr*)src;
345 // Set up callback functions.
346 src->pub.init_source = init_source;
347 src->pub.fill_input_buffer = fill_input_buffer;
348 src->pub.skip_input_data = skip_input_data;
349 src->pub.resync_to_restart = jpeg_resync_to_restart;
350 src->pub.term_source = term_source;
354 // Retain ICC color profile markers for color management.
355 setup_read_icc_profile(&m_info);
358 // Keep APP1 blocks, for obtaining exif data.
359 jpeg_save_markers(&m_info, exifMarker, 0xFFFF);
369 decoder_source_mgr* src = (decoder_source_mgr*)m_info.src;
375 clearColorTransform();
377 jpeg_destroy_decompress(&m_info);
380 void skipBytes(long numBytes)
382 decoder_source_mgr* src = (decoder_source_mgr*)m_info.src;
383 long bytesToSkip = std::min(numBytes, (long)src->pub.bytes_in_buffer);
384 src->pub.bytes_in_buffer -= (size_t)bytesToSkip;
385 src->pub.next_input_byte += bytesToSkip;
387 m_bytesToSkip = std::max(numBytes - bytesToSkip, static_cast<long>(0));
390 bool decode(const SharedBuffer& data, bool onlySize)
392 unsigned newByteCount = data.size() - m_bufferLength;
393 unsigned readOffset = m_bufferLength - m_info.src->bytes_in_buffer;
395 m_info.src->bytes_in_buffer += newByteCount;
396 m_info.src->next_input_byte = (JOCTET*)(data.data()) + readOffset;
398 // If we still have bytes to skip, try to skip those now.
400 skipBytes(m_bytesToSkip);
402 m_bufferLength = data.size();
404 // We need to do the setjmp here. Otherwise bad things will happen
405 if (setjmp(m_err.setjmp_buffer))
406 return m_decoder->setFailed();
408 J_COLOR_SPACE overrideColorSpace = JCS_UNKNOWN;
411 // Read file parameters with jpeg_read_header().
412 if (jpeg_read_header(&m_info, true) == JPEG_SUSPENDED)
413 return false; // I/O suspension.
415 switch (m_info.jpeg_color_space) {
417 // libjpeg can convert YCbCr image pixels to RGB.
418 m_info.out_color_space = rgbOutputColorSpace();
419 if (m_decoder->hasImagePlanes() && (yuvSubsampling(m_info) != YUV_UNKNOWN))
420 overrideColorSpace = JCS_YCbCr;
424 // libjpeg can convert GRAYSCALE image pixels to RGB.
425 m_info.out_color_space = rgbOutputColorSpace();
426 #if defined(TURBO_JPEG_RGB_SWIZZLE)
427 if (m_info.saw_JFIF_marker)
429 // FIXME: Swizzle decoding does not support Adobe transform=0
430 // images (yet), so revert to using JSC_RGB in that case.
431 if (m_info.saw_Adobe_marker && !m_info.Adobe_transform)
432 m_info.out_color_space = JCS_RGB;
437 // libjpeg can convert YCCK to CMYK, but neither to RGB, so we
438 // manually convert CMKY to RGB.
439 m_info.out_color_space = JCS_CMYK;
442 return m_decoder->setFailed();
445 m_state = JPEG_START_DECOMPRESS;
447 // We can fill in the size now that the header is available.
448 if (!m_decoder->setSize(m_info.image_width, m_info.image_height))
451 // Calculate and set decoded size.
452 m_info.scale_num = m_decoder->desiredScaleNumerator();
453 m_info.scale_denom = scaleDenominator;
454 jpeg_calc_output_dimensions(&m_info);
455 m_decoder->setDecodedSize(m_info.output_width, m_info.output_height);
457 m_decoder->setOrientation(readImageOrientation(info()));
460 // Allow color management of the decoded RGBA pixels if possible.
461 if (!m_decoder->ignoresGammaAndColorProfile()) {
462 ColorProfile colorProfile;
463 readColorProfile(info(), colorProfile);
464 createColorTransform(colorProfile, colorSpaceHasAlpha(m_info.out_color_space));
466 overrideColorSpace = JCS_UNKNOWN;
467 #if defined(TURBO_JPEG_RGB_SWIZZLE)
468 // Input RGBA data to qcms. Note: restored to BGRA on output.
469 if (m_info.out_color_space == JCS_EXT_BGRA)
470 m_info.out_color_space = JCS_EXT_RGBA;
473 m_decoder->setHasColorProfile(!!m_transform);
476 if (overrideColorSpace == JCS_YCbCr) {
477 m_info.out_color_space = JCS_YCbCr;
478 m_info.raw_data_out = TRUE;
479 m_uvSize = computeYUVSize(&m_info, 1, ImageDecoder::SizeForMemoryAllocation); // U size and V size have to be the same if we got here
482 // Don't allocate a giant and superfluous memory buffer when the
483 // image is a sequential JPEG.
484 m_info.buffered_image = jpeg_has_multiple_scans(&m_info);
487 // We can stop here. Reduce our buffer length and available data.
488 m_bufferLength -= m_info.src->bytes_in_buffer;
489 m_info.src->bytes_in_buffer = 0;
494 case JPEG_START_DECOMPRESS:
495 // Set parameters for decompression.
496 // FIXME -- Should reset dct_method and dither mode for final pass
497 // of progressive JPEG.
498 m_info.dct_method = dctMethod();
499 m_info.dither_mode = ditherMode();
500 m_info.do_fancy_upsampling = doFancyUpsampling();
501 m_info.enable_2pass_quant = false;
502 m_info.do_block_smoothing = true;
504 // Make a one-row-high sample array that will go away when done with
505 // image. Always make it big enough to hold an RGB row. Since this
506 // uses the IJG memory manager, it must be allocated before the call
507 // to jpeg_start_compress().
508 // FIXME: note that some output color spaces do not need the samples
509 // buffer. Remove this allocation for those color spaces.
510 m_samples = (*m_info.mem->alloc_sarray)(reinterpret_cast<j_common_ptr>(&m_info), JPOOL_IMAGE, m_info.output_width * 4, m_info.out_color_space == JCS_YCbCr ? 2 : 1);
512 // Start decompressor.
513 if (!jpeg_start_decompress(&m_info))
514 return false; // I/O suspension.
516 // If this is a progressive JPEG ...
517 m_state = (m_info.buffered_image) ? JPEG_DECOMPRESS_PROGRESSIVE : JPEG_DECOMPRESS_SEQUENTIAL;
520 case JPEG_DECOMPRESS_SEQUENTIAL:
521 if (m_state == JPEG_DECOMPRESS_SEQUENTIAL) {
523 if (!m_decoder->outputScanlines())
524 return false; // I/O suspension.
526 // If we've completed image output...
527 ASSERT(m_info.output_scanline == m_info.output_height);
532 case JPEG_DECOMPRESS_PROGRESSIVE:
533 if (m_state == JPEG_DECOMPRESS_PROGRESSIVE) {
536 status = jpeg_consume_input(&m_info);
537 } while ((status != JPEG_SUSPENDED) && (status != JPEG_REACHED_EOI));
540 if (!m_info.output_scanline) {
541 int scan = m_info.input_scan_number;
543 // If we haven't displayed anything yet
544 // (output_scan_number == 0) and we have enough data for
545 // a complete scan, force output of the last full scan.
546 if (!m_info.output_scan_number && (scan > 1) && (status != JPEG_REACHED_EOI))
549 if (!jpeg_start_output(&m_info, scan))
550 return false; // I/O suspension.
553 if (m_info.output_scanline == 0xffffff)
554 m_info.output_scanline = 0;
556 // If outputScanlines() fails, it deletes |this|. Therefore,
557 // copy the decoder pointer and use it to check for failure
558 // to avoid member access in the failure case.
559 JPEGImageDecoder* decoder = m_decoder;
560 if (!decoder->outputScanlines()) {
561 if (decoder->failed()) // Careful; |this| is deleted.
563 if (!m_info.output_scanline)
564 // Didn't manage to read any lines - flag so we
565 // don't call jpeg_start_output() multiple times for
567 m_info.output_scanline = 0xffffff;
568 return false; // I/O suspension.
571 if (m_info.output_scanline == m_info.output_height) {
572 if (!jpeg_finish_output(&m_info))
573 return false; // I/O suspension.
575 if (jpeg_input_complete(&m_info) && (m_info.input_scan_number == m_info.output_scan_number))
578 m_info.output_scanline = 0;
587 // Finish decompression.
588 return jpeg_finish_decompress(&m_info);
591 // We can get here if the constructor failed.
592 return m_decoder->setFailed();
598 jpeg_decompress_struct* info() { return &m_info; }
599 JSAMPARRAY samples() const { return m_samples; }
600 JPEGImageDecoder* decoder() { return m_decoder; }
601 IntSize uvSize() const { return m_uvSize; }
603 qcms_transform* colorTransform() const { return m_transform; }
605 void clearColorTransform()
608 qcms_transform_release(m_transform);
612 void createColorTransform(const ColorProfile& colorProfile, bool hasAlpha)
614 clearColorTransform();
616 if (colorProfile.isEmpty())
618 qcms_profile* deviceProfile = ImageDecoder::qcmsOutputDeviceProfile();
621 qcms_profile* inputProfile = qcms_profile_from_memory(colorProfile.data(), colorProfile.size());
624 // We currently only support color profiles for RGB profiled images.
625 ASSERT(icSigRgbData == qcms_profile_get_color_space(inputProfile));
626 qcms_data_type dataFormat = hasAlpha ? QCMS_DATA_RGBA_8 : QCMS_DATA_RGB_8;
627 // FIXME: Don't force perceptual intent if the image profile contains an intent.
628 m_transform = qcms_transform_create(inputProfile, dataFormat, deviceProfile, dataFormat, QCMS_INTENT_PERCEPTUAL);
629 qcms_profile_release(inputProfile);
634 JPEGImageDecoder* m_decoder;
635 unsigned m_bufferLength;
638 jpeg_decompress_struct m_info;
639 decoder_error_mgr m_err;
642 JSAMPARRAY m_samples;
647 qcms_transform* m_transform;
651 // Override the standard error method in the IJG JPEG decoder code.
652 void error_exit(j_common_ptr cinfo)
654 // Return control to the setjmp point.
655 decoder_error_mgr *err = reinterpret_cast_ptr<decoder_error_mgr *>(cinfo->err);
656 longjmp(err->setjmp_buffer, -1);
659 void init_source(j_decompress_ptr)
663 void skip_input_data(j_decompress_ptr jd, long num_bytes)
665 decoder_source_mgr *src = (decoder_source_mgr *)jd->src;
666 src->decoder->skipBytes(num_bytes);
669 boolean fill_input_buffer(j_decompress_ptr)
671 // Our decode step always sets things up properly, so if this method is ever
672 // called, then we have hit the end of the buffer. A return value of false
673 // indicates that we have no data to supply yet.
677 void term_source(j_decompress_ptr jd)
679 decoder_source_mgr *src = (decoder_source_mgr *)jd->src;
680 src->decoder->decoder()->jpegComplete();
683 JPEGImageDecoder::JPEGImageDecoder(ImageSource::AlphaOption alphaOption,
684 ImageSource::GammaAndColorProfileOption gammaAndColorProfileOption,
685 size_t maxDecodedBytes)
686 : ImageDecoder(alphaOption, gammaAndColorProfileOption, maxDecodedBytes)
687 , m_hasColorProfile(false)
691 JPEGImageDecoder::~JPEGImageDecoder()
695 bool JPEGImageDecoder::isSizeAvailable()
697 if (!ImageDecoder::isSizeAvailable())
700 return ImageDecoder::isSizeAvailable();
703 bool JPEGImageDecoder::setSize(unsigned width, unsigned height)
705 if (!ImageDecoder::setSize(width, height))
708 if (!desiredScaleNumerator())
711 setDecodedSize(width, height);
715 void JPEGImageDecoder::setDecodedSize(unsigned width, unsigned height)
717 m_decodedSize = IntSize(width, height);
720 IntSize JPEGImageDecoder::decodedYUVSize(int component, ImageDecoder::SizeType sizeType) const
722 ASSERT((component >= 0) && (component <= 2) && m_reader);
723 const jpeg_decompress_struct* info = m_reader->info();
725 ASSERT(info->out_color_space == JCS_YCbCr);
726 return computeYUVSize(info, component, sizeType);
729 unsigned JPEGImageDecoder::desiredScaleNumerator() const
731 size_t originalBytes = size().width() * size().height() * 4;
732 if (originalBytes <= m_maxDecodedBytes) {
733 return scaleDenominator;
736 // Downsample according to the maximum decoded size.
737 unsigned scaleNumerator = static_cast<unsigned>(floor(sqrt(
738 // MSVC needs explicit parameter type for sqrt().
739 static_cast<float>(m_maxDecodedBytes * scaleDenominator * scaleDenominator / originalBytes))));
741 return scaleNumerator;
744 bool JPEGImageDecoder::canDecodeToYUV() const
746 ASSERT(ImageDecoder::isSizeAvailable() && m_reader);
748 return m_reader->info()->out_color_space == JCS_YCbCr;
751 bool JPEGImageDecoder::decodeToYUV()
753 if (!hasImagePlanes())
755 PlatformInstrumentation::willDecodeImage("JPEG");
757 PlatformInstrumentation::didDecodeImage();
761 ImageFrame* JPEGImageDecoder::frameBufferAtIndex(size_t index)
766 if (m_frameBufferCache.isEmpty()) {
767 m_frameBufferCache.resize(1);
768 m_frameBufferCache[0].setPremultiplyAlpha(m_premultiplyAlpha);
771 ImageFrame& frame = m_frameBufferCache[0];
772 if (frame.status() != ImageFrame::FrameComplete) {
773 PlatformInstrumentation::willDecodeImage("JPEG");
775 PlatformInstrumentation::didDecodeImage();
778 frame.notifyBitmapIfPixelsChanged();
782 bool JPEGImageDecoder::setFailed()
785 return ImageDecoder::setFailed();
788 void JPEGImageDecoder::setImagePlanes(PassOwnPtr<ImagePlanes> imagePlanes)
790 m_imagePlanes = imagePlanes;
793 template <J_COLOR_SPACE colorSpace> void setPixel(ImageFrame& buffer, ImageFrame::PixelData* pixel, JSAMPARRAY samples, int column)
795 ASSERT_NOT_REACHED();
798 template <> void setPixel<JCS_RGB>(ImageFrame& buffer, ImageFrame::PixelData* pixel, JSAMPARRAY samples, int column)
800 JSAMPLE* jsample = *samples + column * 3;
801 buffer.setRGBARaw(pixel, jsample[0], jsample[1], jsample[2], 255);
804 template <> void setPixel<JCS_CMYK>(ImageFrame& buffer, ImageFrame::PixelData* pixel, JSAMPARRAY samples, int column)
806 JSAMPLE* jsample = *samples + column * 4;
808 // Source is 'Inverted CMYK', output is RGB.
809 // See: http://www.easyrgb.com/math.php?MATH=M12#text12
810 // Or: http://www.ilkeratalay.com/colorspacesfaq.php#rgb
812 // X = X * (1 - K ) + K [for X = C, M, or Y]
813 // Thus, from Inverted CMYK to CMY is:
814 // X = (1-iX) * (1 - (1-iK)) + (1-iK) => 1 - iX*iK
815 // From CMY (0..1) to RGB (0..1):
816 // R = 1 - C => 1 - (1 - iC*iK) => iC*iK [G and B similar]
817 unsigned k = jsample[3];
818 buffer.setRGBARaw(pixel, jsample[0] * k / 255, jsample[1] * k / 255, jsample[2] * k / 255, 255);
821 template <J_COLOR_SPACE colorSpace> bool outputRows(JPEGImageReader* reader, ImageFrame& buffer)
823 JSAMPARRAY samples = reader->samples();
824 jpeg_decompress_struct* info = reader->info();
825 int width = info->output_width;
827 while (info->output_scanline < info->output_height) {
828 // jpeg_read_scanlines will increase the scanline counter, so we
829 // save the scanline before calling it.
830 int y = info->output_scanline;
831 // Request one scanline: returns 0 or 1 scanlines.
832 if (jpeg_read_scanlines(info, samples, 1) != 1)
835 if (reader->colorTransform() && colorSpace == JCS_RGB)
836 qcms_transform_data(reader->colorTransform(), *samples, *samples, width);
838 ImageFrame::PixelData* pixel = buffer.getAddr(0, y);
839 for (int x = 0; x < width; ++pixel, ++x)
840 setPixel<colorSpace>(buffer, pixel, samples, x);
843 buffer.setPixelsChanged(true);
847 static bool outputRawData(JPEGImageReader* reader, ImagePlanes* imagePlanes)
849 JSAMPARRAY samples = reader->samples();
850 jpeg_decompress_struct* info = reader->info();
851 JSAMPARRAY bufferraw[3];
852 JSAMPROW bufferraw2[32];
853 bufferraw[0] = &bufferraw2[0]; // Y channel rows (8 or 16)
854 bufferraw[1] = &bufferraw2[16]; // U channel rows (8)
855 bufferraw[2] = &bufferraw2[24]; // V channel rows (8)
856 int yWidth = info->output_width;
857 int yHeight = info->output_height;
858 int yMaxH = yHeight - 1;
859 int v = info->cur_comp_info[0]->v_samp_factor;
860 IntSize uvSize = reader->uvSize();
861 int uvMaxH = uvSize.height() - 1;
862 JSAMPROW outputY = static_cast<JSAMPROW>(imagePlanes->plane(0));
863 JSAMPROW outputU = static_cast<JSAMPROW>(imagePlanes->plane(1));
864 JSAMPROW outputV = static_cast<JSAMPROW>(imagePlanes->plane(2));
865 size_t rowBytesY = imagePlanes->rowBytes(0);
866 size_t rowBytesU = imagePlanes->rowBytes(1);
867 size_t rowBytesV = imagePlanes->rowBytes(2);
869 int yScanlinesToRead = DCTSIZE * v;
870 JSAMPROW yLastRow = *samples;
871 JSAMPROW uLastRow = yLastRow + 2 * yWidth;
872 JSAMPROW vLastRow = uLastRow + 2 * yWidth;
873 JSAMPROW dummyRow = vLastRow + 2 * yWidth;
875 while (info->output_scanline < info->output_height) {
876 // Request 8 or 16 scanlines: returns 0 or more scanlines.
877 bool hasYLastRow(false), hasUVLastRow(false);
878 // Assign 8 or 16 rows of memory to read the Y channel.
879 for (int i = 0; i < yScanlinesToRead; ++i) {
880 int scanline = (info->output_scanline + i);
881 if (scanline < yMaxH) {
882 bufferraw2[i] = &outputY[scanline * rowBytesY];
883 } else if (scanline == yMaxH) {
884 bufferraw2[i] = yLastRow;
887 bufferraw2[i] = dummyRow;
890 int scaledScanline = info->output_scanline / v;
891 // Assign 8 rows of memory to read the U and V channels.
892 for (int i = 0; i < 8; ++i) {
893 int scanline = (scaledScanline + i);
894 if (scanline < uvMaxH) {
895 bufferraw2[16 + i] = &outputU[scanline * rowBytesU];
896 bufferraw2[24 + i] = &outputV[scanline * rowBytesV];
897 } else if (scanline == uvMaxH) {
898 bufferraw2[16 + i] = uLastRow;
899 bufferraw2[24 + i] = vLastRow;
902 bufferraw2[16 + i] = dummyRow;
903 bufferraw2[24 + i] = dummyRow;
906 JDIMENSION scanlinesRead = jpeg_read_raw_data(info, bufferraw, yScanlinesToRead);
908 if (scanlinesRead == 0)
912 memcpy(&outputY[yMaxH * rowBytesY], yLastRow, yWidth);
915 memcpy(&outputU[uvMaxH * rowBytesU], uLastRow, uvSize.width());
916 memcpy(&outputV[uvMaxH * rowBytesV], vLastRow, uvSize.width());
920 info->output_scanline = std::min(info->output_scanline, info->output_height);
925 bool JPEGImageDecoder::outputScanlines()
927 if (hasImagePlanes()) {
928 return outputRawData(m_reader.get(), m_imagePlanes.get());
931 if (m_frameBufferCache.isEmpty())
934 jpeg_decompress_struct* info = m_reader->info();
936 // Initialize the framebuffer if needed.
937 ImageFrame& buffer = m_frameBufferCache[0];
938 if (buffer.status() == ImageFrame::FrameEmpty) {
939 ASSERT(info->output_width == static_cast<JDIMENSION>(m_decodedSize.width()));
940 ASSERT(info->output_height == static_cast<JDIMENSION>(m_decodedSize.height()));
942 if (!buffer.setSize(info->output_width, info->output_height))
944 buffer.setStatus(ImageFrame::FramePartial);
945 // The buffer is transparent outside the decoded area while the image is
946 // loading. The completed image will be marked fully opaque in jpegComplete().
947 buffer.setHasAlpha(true);
949 // For JPEGs, the frame always fills the entire image.
950 buffer.setOriginalFrameRect(IntRect(IntPoint(), size()));
953 #if defined(TURBO_JPEG_RGB_SWIZZLE)
954 if (turboSwizzled(info->out_color_space)) {
955 while (info->output_scanline < info->output_height) {
956 unsigned char* row = reinterpret_cast<unsigned char*>(buffer.getAddr(0, info->output_scanline));
957 if (jpeg_read_scanlines(info, &row, 1) != 1)
960 if (qcms_transform* transform = m_reader->colorTransform())
961 qcms_transform_data_type(transform, row, row, info->output_width, rgbOutputColorSpace() == JCS_EXT_BGRA ? QCMS_OUTPUT_BGRX : QCMS_OUTPUT_RGBX);
964 buffer.setPixelsChanged(true);
969 switch (info->out_color_space) {
971 return outputRows<JCS_RGB>(m_reader.get(), buffer);
973 return outputRows<JCS_CMYK>(m_reader.get(), buffer);
975 ASSERT_NOT_REACHED();
981 void JPEGImageDecoder::jpegComplete()
983 if (m_frameBufferCache.isEmpty())
986 // Hand back an appropriately sized buffer, even if the image ended up being
988 ImageFrame& buffer = m_frameBufferCache[0];
989 buffer.setHasAlpha(false);
990 buffer.setStatus(ImageFrame::FrameComplete);
993 void JPEGImageDecoder::decode(bool onlySize)
999 m_reader = adoptPtr(new JPEGImageReader(this));
1002 // If we couldn't decode the image but we've received all the data, decoding
1004 if (!m_reader->decode(*m_data, onlySize) && isAllDataReceived())
1006 // If we're done decoding the image, we don't need the JPEGImageReader
1007 // anymore. (If we failed, |m_reader| has already been cleared.)
1008 else if ((!m_frameBufferCache.isEmpty() && (m_frameBufferCache[0].status() == ImageFrame::FrameComplete)) || (hasImagePlanes() && !onlySize))