| /* |
| * Copyright (C) 2006 Apple Inc. |
| * |
| * Portions are Copyright (C) 2001-6 mozilla.org |
| * |
| * Other contributors: |
| * Stuart Parmenter <stuart@mozilla.com> |
| * |
| * Copyright (C) 2007-2009 Torch Mobile, Inc. |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| * |
| * Alternatively, the contents of this file may be used under the terms |
| * of either the Mozilla Public License Version 1.1, found at |
| * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public |
| * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html |
| * (the "GPL"), in which case the provisions of the MPL or the GPL are |
| * applicable instead of those above. If you wish to allow use of your |
| * version of this file only under the terms of one of those two |
| * licenses (the MPL or the GPL) and not to allow others to use your |
| * version of this file under the LGPL, indicate your decision by |
| * deletingthe provisions above and replace them with the notice and |
| * other provisions required by the MPL or the GPL, as the case may be. |
| * If you do not delete the provisions above, a recipient may use your |
| * version of this file under any of the LGPL, the MPL or the GPL. |
| */ |
| |
| #include "config.h" |
| #include "JPEGImageDecoder.h" |
| |
| extern "C" { |
| #if USE(ICCJPEG) |
| #include <iccjpeg.h> |
| #endif |
| #include <setjmp.h> |
| } |
| |
| #if CPU(BIG_ENDIAN) || CPU(MIDDLE_ENDIAN) |
| #define ASSUME_LITTLE_ENDIAN 0 |
| #else |
| #define ASSUME_LITTLE_ENDIAN 1 |
| #endif |
| |
| #if defined(JCS_ALPHA_EXTENSIONS) && ASSUME_LITTLE_ENDIAN |
| #define TURBO_JPEG_RGB_SWIZZLE |
| inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_EXT_BGRA; } |
| inline bool turboSwizzled(J_COLOR_SPACE colorSpace) { return colorSpace == JCS_EXT_RGBA || colorSpace == JCS_EXT_BGRA; } |
| inline bool colorSpaceHasAlpha(J_COLOR_SPACE colorSpace) { return turboSwizzled(colorSpace); } |
| #else |
| inline J_COLOR_SPACE rgbOutputColorSpace() { return JCS_RGB; } |
| inline bool colorSpaceHasAlpha(J_COLOR_SPACE) { return false; } |
| #endif |
| |
| #if USE(LOW_QUALITY_IMAGE_NO_JPEG_DITHERING) |
| inline J_DCT_METHOD dctMethod() { return JDCT_IFAST; } |
| inline J_DITHER_MODE ditherMode() { return JDITHER_NONE; } |
| #else |
| inline J_DCT_METHOD dctMethod() { return JDCT_ISLOW; } |
| inline J_DITHER_MODE ditherMode() { return JDITHER_FS; } |
| #endif |
| |
| #if USE(LOW_QUALITY_IMAGE_NO_JPEG_FANCY_UPSAMPLING) |
| inline bool doFancyUpsampling() { return false; } |
| #else |
| inline bool doFancyUpsampling() { return true; } |
| #endif |
| |
| const int exifMarker = JPEG_APP0 + 1; |
| |
| namespace WebCore { |
| |
| struct decoder_error_mgr { |
| struct jpeg_error_mgr pub; // "public" fields for IJG library |
| jmp_buf setjmp_buffer; // For handling catastropic errors |
| }; |
| |
| enum jstate { |
| JPEG_HEADER, // Reading JFIF headers |
| JPEG_START_DECOMPRESS, |
| JPEG_DECOMPRESS_PROGRESSIVE, // Output progressive pixels |
| JPEG_DECOMPRESS_SEQUENTIAL, // Output sequential pixels |
| JPEG_DONE, |
| JPEG_ERROR |
| }; |
| |
| void init_source(j_decompress_ptr jd); |
| boolean fill_input_buffer(j_decompress_ptr jd); |
| void skip_input_data(j_decompress_ptr jd, long num_bytes); |
| void term_source(j_decompress_ptr jd); |
| void error_exit(j_common_ptr cinfo); |
| |
| // Implementation of a JPEG src object that understands our state machine |
| struct decoder_source_mgr { |
| // public fields; must be first in this struct! |
| struct jpeg_source_mgr pub; |
| |
| JPEGImageReader* decoder; |
| }; |
| |
| static unsigned readUint16(JOCTET* data, bool isBigEndian) |
| { |
| if (isBigEndian) |
| return (GETJOCTET(data[0]) << 8) | GETJOCTET(data[1]); |
| return (GETJOCTET(data[1]) << 8) | GETJOCTET(data[0]); |
| } |
| |
| static unsigned readUint32(JOCTET* data, bool isBigEndian) |
| { |
| if (isBigEndian) |
| return (GETJOCTET(data[0]) << 24) | (GETJOCTET(data[1]) << 16) | (GETJOCTET(data[2]) << 8) | GETJOCTET(data[3]); |
| return (GETJOCTET(data[3]) << 24) | (GETJOCTET(data[2]) << 16) | (GETJOCTET(data[1]) << 8) | GETJOCTET(data[0]); |
| } |
| |
| static bool checkExifHeader(jpeg_saved_marker_ptr marker, bool& isBigEndian, unsigned& ifdOffset) |
| { |
| // For exif data, the APP1 block is followed by 'E', 'x', 'i', 'f', '\0', |
| // then a fill byte, and then a tiff file that contains the metadata. |
| // A tiff file starts with 'I', 'I' (intel / little endian byte order) or |
| // 'M', 'M' (motorola / big endian byte order), followed by (uint16_t)42, |
| // followed by an uint32_t with the offset to the tag block, relative to the |
| // tiff file start. |
| const unsigned exifHeaderSize = 14; |
| if (!(marker->marker == exifMarker |
| && marker->data_length >= exifHeaderSize |
| && marker->data[0] == 'E' |
| && marker->data[1] == 'x' |
| && marker->data[2] == 'i' |
| && marker->data[3] == 'f' |
| && marker->data[4] == '\0' |
| // data[5] is a fill byte |
| && ((marker->data[6] == 'I' && marker->data[7] == 'I') |
| || (marker->data[6] == 'M' && marker->data[7] == 'M')))) |
| return false; |
| |
| isBigEndian = marker->data[6] == 'M'; |
| if (readUint16(marker->data + 8, isBigEndian) != 42) |
| return false; |
| |
| ifdOffset = readUint32(marker->data + 10, isBigEndian); |
| return true; |
| } |
| |
| static ImageOrientation readImageOrientation(jpeg_decompress_struct* info) |
| { |
| // The JPEG decoder looks at EXIF metadata. |
| // FIXME: Possibly implement XMP and IPTC support. |
| const unsigned orientationTag = 0x112; |
| const unsigned shortType = 3; |
| for (jpeg_saved_marker_ptr marker = info->marker_list; marker; marker = marker->next) { |
| bool isBigEndian; |
| unsigned ifdOffset; |
| if (!checkExifHeader(marker, isBigEndian, ifdOffset)) |
| continue; |
| const unsigned offsetToTiffData = 6; // Account for 'Exif\0<fill byte>' header. |
| if (marker->data_length < offsetToTiffData || ifdOffset >= marker->data_length - offsetToTiffData) |
| continue; |
| ifdOffset += offsetToTiffData; |
| |
| // The jpeg exif container format contains a tiff block for metadata. |
| // A tiff image file directory (ifd) consists of a uint16_t describing |
| // the number of ifd entries, followed by that many entries. |
| // When touching this code, it's useful to look at the tiff spec: |
| // http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf |
| JOCTET* ifd = marker->data + ifdOffset; |
| JOCTET* end = marker->data + marker->data_length; |
| if (end - ifd < 2) |
| continue; |
| unsigned tagCount = readUint16(ifd, isBigEndian); |
| ifd += 2; // Skip over the uint16 that was just read. |
| |
| // Every ifd entry is 2 bytes of tag, 2 bytes of contents datatype, |
| // 4 bytes of number-of-elements, and 4 bytes of either offset to the |
| // tag data, or if the data is small enough, the inlined data itself. |
| const int ifdEntrySize = 12; |
| for (unsigned i = 0; i < tagCount && end - ifd >= ifdEntrySize; ++i, ifd += ifdEntrySize) { |
| unsigned tag = readUint16(ifd, isBigEndian); |
| unsigned type = readUint16(ifd + 2, isBigEndian); |
| unsigned count = readUint32(ifd + 4, isBigEndian); |
| if (tag == orientationTag && type == shortType && count == 1) |
| return ImageOrientation::fromEXIFValue(readUint16(ifd + 8, isBigEndian)); |
| } |
| } |
| |
| return ImageOrientation(); |
| } |
| |
| class JPEGImageReader { |
| WTF_MAKE_FAST_ALLOCATED; |
| public: |
| JPEGImageReader(JPEGImageDecoder* decoder) |
| : m_decoder(decoder) |
| , m_bufferLength(0) |
| , m_bytesToSkip(0) |
| , m_state(JPEG_HEADER) |
| , m_samples(0) |
| { |
| memset(&m_info, 0, sizeof(jpeg_decompress_struct)); |
| |
| // We set up the normal JPEG error routines, then override error_exit. |
| m_info.err = jpeg_std_error(&m_err.pub); |
| m_err.pub.error_exit = error_exit; |
| |
| // Allocate and initialize JPEG decompression object. |
| jpeg_create_decompress(&m_info); |
| |
| decoder_source_mgr* src = 0; |
| if (!m_info.src) { |
| src = (decoder_source_mgr*)fastCalloc(sizeof(decoder_source_mgr), 1); |
| if (!src) { |
| m_state = JPEG_ERROR; |
| return; |
| } |
| } |
| |
| m_info.src = (jpeg_source_mgr*)src; |
| |
| // Set up callback functions. |
| src->pub.init_source = init_source; |
| src->pub.fill_input_buffer = fill_input_buffer; |
| src->pub.skip_input_data = skip_input_data; |
| src->pub.resync_to_restart = jpeg_resync_to_restart; |
| src->pub.term_source = term_source; |
| src->decoder = this; |
| |
| #if USE(ICCJPEG) |
| // Retain ICC color profile markers for color management. |
| setup_read_icc_profile(&m_info); |
| #endif |
| |
| // Keep APP1 blocks, for obtaining exif data. |
| jpeg_save_markers(&m_info, exifMarker, 0xFFFF); |
| } |
| |
| ~JPEGImageReader() |
| { |
| close(); |
| } |
| |
| void close() |
| { |
| decoder_source_mgr* src = (decoder_source_mgr*)m_info.src; |
| if (src) |
| fastFree(src); |
| m_info.src = 0; |
| |
| jpeg_destroy_decompress(&m_info); |
| } |
| |
| void skipBytes(long numBytes) |
| { |
| decoder_source_mgr* src = (decoder_source_mgr*)m_info.src; |
| long bytesToSkip = std::min(numBytes, (long)src->pub.bytes_in_buffer); |
| src->pub.bytes_in_buffer -= (size_t)bytesToSkip; |
| src->pub.next_input_byte += bytesToSkip; |
| |
| m_bytesToSkip = std::max(numBytes - bytesToSkip, static_cast<long>(0)); |
| } |
| |
| bool decode(const SharedBuffer& data, bool onlySize) |
| { |
| m_decodingSizeOnly = onlySize; |
| |
| unsigned newByteCount = data.size() - m_bufferLength; |
| unsigned readOffset = m_bufferLength - m_info.src->bytes_in_buffer; |
| |
| m_info.src->bytes_in_buffer += newByteCount; |
| m_info.src->next_input_byte = (JOCTET*)(data.data()) + readOffset; |
| |
| // If we still have bytes to skip, try to skip those now. |
| if (m_bytesToSkip) |
| skipBytes(m_bytesToSkip); |
| |
| m_bufferLength = data.size(); |
| |
| // We need to do the setjmp here. Otherwise bad things will happen |
| if (setjmp(m_err.setjmp_buffer)) |
| return m_decoder->setFailed(); |
| |
| switch (m_state) { |
| case JPEG_HEADER: |
| // Read file parameters with jpeg_read_header(). |
| if (jpeg_read_header(&m_info, TRUE) == JPEG_SUSPENDED) |
| return false; // I/O suspension. |
| |
| switch (m_info.jpeg_color_space) { |
| case JCS_GRAYSCALE: |
| case JCS_RGB: |
| case JCS_YCbCr: |
| // libjpeg can convert GRAYSCALE and YCbCr image pixels to RGB. |
| m_info.out_color_space = rgbOutputColorSpace(); |
| #if defined(TURBO_JPEG_RGB_SWIZZLE) |
| if (m_info.saw_JFIF_marker) |
| break; |
| // FIXME: Swizzle decoding does not support Adobe transform=0 |
| // images (yet), so revert to using JSC_RGB in that case. |
| if (m_info.saw_Adobe_marker && !m_info.Adobe_transform) |
| m_info.out_color_space = JCS_RGB; |
| #endif |
| break; |
| case JCS_CMYK: |
| case JCS_YCCK: |
| // libjpeg can convert YCCK to CMYK, but neither to RGB, so we |
| // manually convert CMKY to RGB. |
| m_info.out_color_space = JCS_CMYK; |
| break; |
| default: |
| return m_decoder->setFailed(); |
| } |
| |
| m_state = JPEG_START_DECOMPRESS; |
| |
| // We can fill in the size now that the header is available. |
| if (!m_decoder->setSize(IntSize(m_info.image_width, m_info.image_height))) |
| return false; |
| |
| m_decoder->setOrientation(readImageOrientation(info())); |
| |
| // Don't allocate a giant and superfluous memory buffer when the |
| // image is a sequential JPEG. |
| m_info.buffered_image = jpeg_has_multiple_scans(&m_info); |
| |
| // Used to set up image size so arrays can be allocated. |
| jpeg_calc_output_dimensions(&m_info); |
| |
| // Make a one-row-high sample array that will go away when done with |
| // image. Always make it big enough to hold an RGB row. Since this |
| // uses the IJG memory manager, it must be allocated before the call |
| // to jpeg_start_compress(). |
| // FIXME: note that some output color spaces do not need the samples |
| // buffer. Remove this allocation for those color spaces. |
| m_samples = (*m_info.mem->alloc_sarray)((j_common_ptr) &m_info, JPOOL_IMAGE, m_info.output_width * 4, 1); |
| |
| if (m_decodingSizeOnly) { |
| // We can stop here. Reduce our buffer length and available data. |
| m_bufferLength -= m_info.src->bytes_in_buffer; |
| m_info.src->bytes_in_buffer = 0; |
| return true; |
| } |
| // FALL THROUGH |
| |
| case JPEG_START_DECOMPRESS: |
| // Set parameters for decompression. |
| // FIXME -- Should reset dct_method and dither mode for final pass |
| // of progressive JPEG. |
| m_info.dct_method = dctMethod(); |
| m_info.dither_mode = ditherMode(); |
| m_info.do_fancy_upsampling = doFancyUpsampling() ? TRUE : FALSE; |
| m_info.enable_2pass_quant = FALSE; |
| m_info.do_block_smoothing = TRUE; |
| |
| // Start decompressor. |
| if (!jpeg_start_decompress(&m_info)) |
| return false; // I/O suspension. |
| |
| // If this is a progressive JPEG ... |
| m_state = (m_info.buffered_image) ? JPEG_DECOMPRESS_PROGRESSIVE : JPEG_DECOMPRESS_SEQUENTIAL; |
| // FALL THROUGH |
| |
| case JPEG_DECOMPRESS_SEQUENTIAL: |
| if (m_state == JPEG_DECOMPRESS_SEQUENTIAL) { |
| |
| if (!m_decoder->outputScanlines()) |
| return false; // I/O suspension. |
| |
| // If we've completed image output... |
| ASSERT(m_info.output_scanline == m_info.output_height); |
| m_state = JPEG_DONE; |
| } |
| // FALL THROUGH |
| |
| case JPEG_DECOMPRESS_PROGRESSIVE: |
| if (m_state == JPEG_DECOMPRESS_PROGRESSIVE) { |
| int status; |
| do { |
| status = jpeg_consume_input(&m_info); |
| } while ((status != JPEG_SUSPENDED) && (status != JPEG_REACHED_EOI)); |
| |
| for (;;) { |
| if (!m_info.output_scanline) { |
| int scan = m_info.input_scan_number; |
| |
| // If we haven't displayed anything yet |
| // (output_scan_number == 0) and we have enough data for |
| // a complete scan, force output of the last full scan. |
| if (!m_info.output_scan_number && (scan > 1) && (status != JPEG_REACHED_EOI)) |
| --scan; |
| |
| if (!jpeg_start_output(&m_info, scan)) |
| return false; // I/O suspension. |
| } |
| |
| if (m_info.output_scanline == 0xffffff) |
| m_info.output_scanline = 0; |
| |
| // If outputScanlines() fails, it deletes |this|. Therefore, |
| // copy the decoder pointer and use it to check for failure |
| // to avoid member access in the failure case. |
| JPEGImageDecoder* decoder = m_decoder; |
| if (!decoder->outputScanlines()) { |
| if (decoder->failed()) // Careful; |this| is deleted. |
| return false; |
| if (!m_info.output_scanline) |
| // Didn't manage to read any lines - flag so we |
| // don't call jpeg_start_output() multiple times for |
| // the same scan. |
| m_info.output_scanline = 0xffffff; |
| return false; // I/O suspension. |
| } |
| |
| if (m_info.output_scanline == m_info.output_height) { |
| if (!jpeg_finish_output(&m_info)) |
| return false; // I/O suspension. |
| |
| if (jpeg_input_complete(&m_info) && (m_info.input_scan_number == m_info.output_scan_number)) |
| break; |
| |
| m_info.output_scanline = 0; |
| } |
| } |
| |
| m_state = JPEG_DONE; |
| } |
| // FALL THROUGH |
| |
| case JPEG_DONE: |
| // Finish decompression. |
| return jpeg_finish_decompress(&m_info); |
| |
| case JPEG_ERROR: |
| // We can get here if the constructor failed. |
| return m_decoder->setFailed(); |
| } |
| |
| return true; |
| } |
| |
| jpeg_decompress_struct* info() { return &m_info; } |
| JSAMPARRAY samples() const { return m_samples; } |
| JPEGImageDecoder* decoder() { return m_decoder; } |
| |
| private: |
| JPEGImageDecoder* m_decoder; |
| unsigned m_bufferLength; |
| int m_bytesToSkip; |
| bool m_decodingSizeOnly; |
| |
| jpeg_decompress_struct m_info; |
| decoder_error_mgr m_err; |
| jstate m_state; |
| |
| JSAMPARRAY m_samples; |
| }; |
| |
| // Override the standard error method in the IJG JPEG decoder code. |
| void error_exit(j_common_ptr cinfo) |
| { |
| // Return control to the setjmp point. |
| decoder_error_mgr *err = reinterpret_cast_ptr<decoder_error_mgr *>(cinfo->err); |
| longjmp(err->setjmp_buffer, -1); |
| } |
| |
| void init_source(j_decompress_ptr) |
| { |
| } |
| |
| void skip_input_data(j_decompress_ptr jd, long num_bytes) |
| { |
| decoder_source_mgr *src = (decoder_source_mgr *)jd->src; |
| src->decoder->skipBytes(num_bytes); |
| } |
| |
| boolean fill_input_buffer(j_decompress_ptr) |
| { |
| // Our decode step always sets things up properly, so if this method is ever |
| // called, then we have hit the end of the buffer. A return value of false |
| // indicates that we have no data to supply yet. |
| return FALSE; |
| } |
| |
| void term_source(j_decompress_ptr jd) |
| { |
| decoder_source_mgr *src = (decoder_source_mgr *)jd->src; |
| src->decoder->decoder()->jpegComplete(); |
| } |
| |
| JPEGImageDecoder::JPEGImageDecoder(AlphaOption alphaOption, GammaAndColorProfileOption gammaAndColorProfileOption) |
| : ScalableImageDecoder(alphaOption, gammaAndColorProfileOption) |
| { |
| } |
| |
| JPEGImageDecoder::~JPEGImageDecoder() = default; |
| |
| bool JPEGImageDecoder::setSize(const IntSize& size) |
| { |
| if (!ScalableImageDecoder::setSize(size)) |
| return false; |
| |
| prepareScaleDataIfNecessary(); |
| return true; |
| } |
| |
| ScalableImageDecoderFrame* JPEGImageDecoder::frameBufferAtIndex(size_t index) |
| { |
| if (index) |
| return 0; |
| |
| if (m_frameBufferCache.isEmpty()) |
| m_frameBufferCache.grow(1); |
| |
| auto& frame = m_frameBufferCache[0]; |
| if (!frame.isComplete()) |
| decode(false, isAllDataReceived()); |
| return &frame; |
| } |
| |
| bool JPEGImageDecoder::setFailed() |
| { |
| m_reader = nullptr; |
| return ScalableImageDecoder::setFailed(); |
| } |
| |
| template <J_COLOR_SPACE colorSpace> |
| void setPixel(ScalableImageDecoderFrame& buffer, uint32_t* currentAddress, JSAMPARRAY samples, int column) |
| { |
| JSAMPLE* jsample = *samples + column * (colorSpace == JCS_RGB ? 3 : 4); |
| |
| switch (colorSpace) { |
| case JCS_RGB: |
| buffer.backingStore()->setPixel(currentAddress, jsample[0], jsample[1], jsample[2], 0xFF); |
| break; |
| case JCS_CMYK: |
| // Source is 'Inverted CMYK', output is RGB. |
| // See: http://www.easyrgb.com/math.php?MATH=M12#text12 |
| // Or: http://www.ilkeratalay.com/colorspacesfaq.php#rgb |
| // From CMYK to CMY: |
| // X = X * (1 - K ) + K [for X = C, M, or Y] |
| // Thus, from Inverted CMYK to CMY is: |
| // X = (1-iX) * (1 - (1-iK)) + (1-iK) => 1 - iX*iK |
| // From CMY (0..1) to RGB (0..1): |
| // R = 1 - C => 1 - (1 - iC*iK) => iC*iK [G and B similar] |
| unsigned k = jsample[3]; |
| buffer.backingStore()->setPixel(currentAddress, jsample[0] * k / 255, jsample[1] * k / 255, jsample[2] * k / 255, 0xFF); |
| break; |
| } |
| } |
| |
| template <J_COLOR_SPACE colorSpace, bool isScaled> |
| bool JPEGImageDecoder::outputScanlines(ScalableImageDecoderFrame& buffer) |
| { |
| JSAMPARRAY samples = m_reader->samples(); |
| jpeg_decompress_struct* info = m_reader->info(); |
| int width = isScaled ? m_scaledColumns.size() : info->output_width; |
| |
| while (info->output_scanline < info->output_height) { |
| // jpeg_read_scanlines will increase the scanline counter, so we |
| // save the scanline before calling it. |
| int sourceY = info->output_scanline; |
| /* Request one scanline. Returns 0 or 1 scanlines. */ |
| if (jpeg_read_scanlines(info, samples, 1) != 1) |
| return false; |
| |
| int destY = scaledY(sourceY); |
| if (destY < 0) |
| continue; |
| |
| auto* currentAddress = buffer.backingStore()->pixelAt(0, destY); |
| for (int x = 0; x < width; ++x) { |
| setPixel<colorSpace>(buffer, currentAddress, samples, isScaled ? m_scaledColumns[x] : x); |
| ++currentAddress; |
| } |
| } |
| return true; |
| } |
| |
| template <J_COLOR_SPACE colorSpace> |
| bool JPEGImageDecoder::outputScanlines(ScalableImageDecoderFrame& buffer) |
| { |
| return m_scaled ? outputScanlines<colorSpace, true>(buffer) : outputScanlines<colorSpace, false>(buffer); |
| } |
| |
| bool JPEGImageDecoder::outputScanlines() |
| { |
| if (m_frameBufferCache.isEmpty()) |
| return false; |
| |
| // Initialize the framebuffer if needed. |
| auto& buffer = m_frameBufferCache[0]; |
| if (buffer.isInvalid()) { |
| if (!buffer.initialize(scaledSize(), m_premultiplyAlpha)) |
| return setFailed(); |
| buffer.setDecodingStatus(DecodingStatus::Partial); |
| // The buffer is transparent outside the decoded area while the image is |
| // loading. The completed image will be marked fully opaque in jpegComplete(). |
| buffer.setHasAlpha(true); |
| } |
| |
| jpeg_decompress_struct* info = m_reader->info(); |
| |
| #if defined(TURBO_JPEG_RGB_SWIZZLE) |
| if (!m_scaled && turboSwizzled(info->out_color_space)) { |
| while (info->output_scanline < info->output_height) { |
| unsigned char* row = reinterpret_cast<unsigned char*>(buffer.backingStore()->pixelAt(0, info->output_scanline)); |
| if (jpeg_read_scanlines(info, &row, 1) != 1) |
| return false; |
| } |
| return true; |
| } |
| #endif |
| |
| switch (info->out_color_space) { |
| // The code inside outputScanlines<int, bool> will be executed |
| // for each pixel, so we want to avoid any extra comparisons there. |
| // That is why we use template and template specializations here so |
| // the proper code will be generated at compile time. |
| case JCS_RGB: |
| return outputScanlines<JCS_RGB>(buffer); |
| case JCS_CMYK: |
| return outputScanlines<JCS_CMYK>(buffer); |
| default: |
| ASSERT_NOT_REACHED(); |
| } |
| |
| return setFailed(); |
| } |
| |
| void JPEGImageDecoder::jpegComplete() |
| { |
| if (m_frameBufferCache.isEmpty()) |
| return; |
| |
| // Hand back an appropriately sized buffer, even if the image ended up being |
| // empty. |
| auto& buffer = m_frameBufferCache[0]; |
| buffer.setHasAlpha(false); |
| buffer.setDecodingStatus(DecodingStatus::Complete); |
| } |
| |
| void JPEGImageDecoder::decode(bool onlySize, bool allDataReceived) |
| { |
| if (failed()) |
| return; |
| |
| if (!m_reader) |
| m_reader = std::make_unique<JPEGImageReader>(this); |
| |
| // If we couldn't decode the image but we've received all the data, decoding |
| // has failed. |
| if (!m_reader->decode(*m_data, onlySize) && allDataReceived) |
| setFailed(); |
| // If we're done decoding the image, we don't need the JPEGImageReader |
| // anymore. (If we failed, |m_reader| has already been cleared.) |
| else if (!m_frameBufferCache.isEmpty() && (m_frameBufferCache[0].isComplete())) |
| m_reader = nullptr; |
| } |
| |
| } |
