| /* |
| * Copyright 2007 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| |
| #include "SkImageDecoder.h" |
| #include "SkImageEncoder.h" |
| #include "SkJpegUtility.h" |
| #include "SkColorPriv.h" |
| #include "SkDither.h" |
| #include "SkScaledBitmapSampler.h" |
| #include "SkStream.h" |
| #include "SkTemplates.h" |
| #include "SkTime.h" |
| #include "SkUtils.h" |
| #include "SkRTConf.h" |
| #include "SkRect.h" |
| #include "SkCanvas.h" |
| |
| |
| #include <stdio.h> |
| extern "C" { |
| #include "jpeglib.h" |
| #include "jerror.h" |
| } |
| |
| // These enable timing code that report milliseconds for an encoding/decoding |
| //#define TIME_ENCODE |
| //#define TIME_DECODE |
| |
| // this enables our rgb->yuv code, which is faster than libjpeg on ARM |
| #define WE_CONVERT_TO_YUV |
| |
| // If ANDROID_RGB is defined by in the jpeg headers it indicates that jpeg offers |
| // support for two additional formats (1) JCS_RGBA_8888 and (2) JCS_RGB_565. |
| |
| #if defined(SK_DEBUG) |
| #define DEFAULT_FOR_SUPPRESS_JPEG_IMAGE_DECODER_WARNINGS false |
| #define DEFAULT_FOR_SUPPRESS_JPEG_IMAGE_DECODER_ERRORS false |
| #else // !defined(SK_DEBUG) |
| #define DEFAULT_FOR_SUPPRESS_JPEG_IMAGE_DECODER_WARNINGS true |
| #define DEFAULT_FOR_SUPPRESS_JPEG_IMAGE_DECODER_ERRORS true |
| #endif // defined(SK_DEBUG) |
| SK_CONF_DECLARE(bool, c_suppressJPEGImageDecoderWarnings, |
| "images.jpeg.suppressDecoderWarnings", |
| DEFAULT_FOR_SUPPRESS_JPEG_IMAGE_DECODER_WARNINGS, |
| "Suppress most JPG warnings when calling decode functions."); |
| SK_CONF_DECLARE(bool, c_suppressJPEGImageDecoderErrors, |
| "images.jpeg.suppressDecoderErrors", |
| DEFAULT_FOR_SUPPRESS_JPEG_IMAGE_DECODER_ERRORS, |
| "Suppress most JPG error messages when decode " |
| "function fails."); |
| |
| ////////////////////////////////////////////////////////////////////////// |
| ////////////////////////////////////////////////////////////////////////// |
| |
| static void overwrite_mem_buffer_size(jpeg_decompress_struct* cinfo) { |
| #ifdef SK_BUILD_FOR_ANDROID |
| /* Check if the device indicates that it has a large amount of system memory |
| * if so, increase the memory allocation to 30MB instead of the default 5MB. |
| */ |
| #ifdef ANDROID_LARGE_MEMORY_DEVICE |
| cinfo->mem->max_memory_to_use = 30 * 1024 * 1024; |
| #else |
| cinfo->mem->max_memory_to_use = 5 * 1024 * 1024; |
| #endif |
| #endif // SK_BUILD_FOR_ANDROID |
| } |
| |
| ////////////////////////////////////////////////////////////////////////// |
| ////////////////////////////////////////////////////////////////////////// |
| |
| static void do_nothing_emit_message(jpeg_common_struct*, int) { |
| /* do nothing */ |
| } |
| static void do_nothing_output_message(j_common_ptr) { |
| /* do nothing */ |
| } |
| |
| static void initialize_info(jpeg_decompress_struct* cinfo, skjpeg_source_mgr* src_mgr) { |
| SkASSERT(cinfo != NULL); |
| SkASSERT(src_mgr != NULL); |
| jpeg_create_decompress(cinfo); |
| overwrite_mem_buffer_size(cinfo); |
| cinfo->src = src_mgr; |
| /* To suppress warnings with a SK_DEBUG binary, set the |
| * environment variable "skia_images_jpeg_suppressDecoderWarnings" |
| * to "true". Inside a program that links to skia: |
| * SK_CONF_SET("images.jpeg.suppressDecoderWarnings", true); */ |
| if (c_suppressJPEGImageDecoderWarnings) { |
| cinfo->err->emit_message = &do_nothing_emit_message; |
| } |
| /* To suppress error messages with a SK_DEBUG binary, set the |
| * environment variable "skia_images_jpeg_suppressDecoderErrors" |
| * to "true". Inside a program that links to skia: |
| * SK_CONF_SET("images.jpeg.suppressDecoderErrors", true); */ |
| if (c_suppressJPEGImageDecoderErrors) { |
| cinfo->err->output_message = &do_nothing_output_message; |
| } |
| } |
| |
| #ifdef SK_BUILD_FOR_ANDROID |
| class SkJPEGImageIndex { |
| public: |
| SkJPEGImageIndex(SkStreamRewindable* stream, SkImageDecoder* decoder) |
| : fSrcMgr(stream, decoder) |
| , fInfoInitialized(false) |
| , fHuffmanCreated(false) |
| , fDecompressStarted(false) |
| { |
| SkDEBUGCODE(fReadHeaderSucceeded = false;) |
| } |
| |
| ~SkJPEGImageIndex() { |
| if (fHuffmanCreated) { |
| // Set to false before calling the libjpeg function, in case |
| // the libjpeg function calls longjmp. Our setjmp handler may |
| // attempt to delete this SkJPEGImageIndex, thus entering this |
| // destructor again. Setting fHuffmanCreated to false first |
| // prevents an infinite loop. |
| fHuffmanCreated = false; |
| jpeg_destroy_huffman_index(&fHuffmanIndex); |
| } |
| if (fDecompressStarted) { |
| // Like fHuffmanCreated, set to false before calling libjpeg |
| // function to prevent potential infinite loop. |
| fDecompressStarted = false; |
| jpeg_finish_decompress(&fCInfo); |
| } |
| if (fInfoInitialized) { |
| this->destroyInfo(); |
| } |
| } |
| |
| /** |
| * Destroy the cinfo struct. |
| * After this call, if a huffman index was already built, it |
| * can be used after calling initializeInfoAndReadHeader |
| * again. Must not be called after startTileDecompress except |
| * in the destructor. |
| */ |
| void destroyInfo() { |
| SkASSERT(fInfoInitialized); |
| SkASSERT(!fDecompressStarted); |
| // Like fHuffmanCreated, set to false before calling libjpeg |
| // function to prevent potential infinite loop. |
| fInfoInitialized = false; |
| jpeg_destroy_decompress(&fCInfo); |
| SkDEBUGCODE(fReadHeaderSucceeded = false;) |
| } |
| |
| /** |
| * Initialize the cinfo struct. |
| * Calls jpeg_create_decompress, makes customizations, and |
| * finally calls jpeg_read_header. Returns true if jpeg_read_header |
| * returns JPEG_HEADER_OK. |
| * If cinfo was already initialized, destroyInfo must be called to |
| * destroy the old one. Must not be called after startTileDecompress. |
| */ |
| bool initializeInfoAndReadHeader() { |
| SkASSERT(!fInfoInitialized && !fDecompressStarted); |
| initialize_info(&fCInfo, &fSrcMgr); |
| fInfoInitialized = true; |
| const bool success = (JPEG_HEADER_OK == jpeg_read_header(&fCInfo, true)); |
| SkDEBUGCODE(fReadHeaderSucceeded = success;) |
| return success; |
| } |
| |
| jpeg_decompress_struct* cinfo() { return &fCInfo; } |
| |
| huffman_index* huffmanIndex() { return &fHuffmanIndex; } |
| |
| /** |
| * Build the index to be used for tile based decoding. |
| * Must only be called after a successful call to |
| * initializeInfoAndReadHeader and must not be called more |
| * than once. |
| */ |
| bool buildHuffmanIndex() { |
| SkASSERT(fReadHeaderSucceeded); |
| SkASSERT(!fHuffmanCreated); |
| jpeg_create_huffman_index(&fCInfo, &fHuffmanIndex); |
| SkASSERT(1 == fCInfo.scale_num && 1 == fCInfo.scale_denom); |
| fHuffmanCreated = jpeg_build_huffman_index(&fCInfo, &fHuffmanIndex); |
| return fHuffmanCreated; |
| } |
| |
| /** |
| * Start tile based decoding. Must only be called after a |
| * successful call to buildHuffmanIndex, and must only be |
| * called once. |
| */ |
| bool startTileDecompress() { |
| SkASSERT(fHuffmanCreated); |
| SkASSERT(fReadHeaderSucceeded); |
| SkASSERT(!fDecompressStarted); |
| if (jpeg_start_tile_decompress(&fCInfo)) { |
| fDecompressStarted = true; |
| return true; |
| } |
| return false; |
| } |
| |
| private: |
| skjpeg_source_mgr fSrcMgr; |
| jpeg_decompress_struct fCInfo; |
| huffman_index fHuffmanIndex; |
| bool fInfoInitialized; |
| bool fHuffmanCreated; |
| bool fDecompressStarted; |
| SkDEBUGCODE(bool fReadHeaderSucceeded;) |
| }; |
| #endif |
| |
| class SkJPEGImageDecoder : public SkImageDecoder { |
| public: |
| #ifdef SK_BUILD_FOR_ANDROID |
| SkJPEGImageDecoder() { |
| fImageIndex = NULL; |
| fImageWidth = 0; |
| fImageHeight = 0; |
| } |
| |
| virtual ~SkJPEGImageDecoder() { |
| SkDELETE(fImageIndex); |
| } |
| #endif |
| |
| virtual Format getFormat() const { |
| return kJPEG_Format; |
| } |
| |
| protected: |
| #ifdef SK_BUILD_FOR_ANDROID |
| virtual bool onBuildTileIndex(SkStreamRewindable *stream, int *width, int *height) SK_OVERRIDE; |
| virtual bool onDecodeSubset(SkBitmap* bitmap, const SkIRect& rect) SK_OVERRIDE; |
| #endif |
| virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE; |
| |
| private: |
| #ifdef SK_BUILD_FOR_ANDROID |
| SkJPEGImageIndex* fImageIndex; |
| int fImageWidth; |
| int fImageHeight; |
| #endif |
| |
| /** |
| * Determine the appropriate bitmap config and out_color_space based on |
| * both the preference of the caller and the jpeg_color_space on the |
| * jpeg_decompress_struct passed in. |
| * Must be called after jpeg_read_header. |
| */ |
| SkBitmap::Config getBitmapConfig(jpeg_decompress_struct*); |
| |
| typedef SkImageDecoder INHERITED; |
| }; |
| |
| ////////////////////////////////////////////////////////////////////////// |
| |
| /* Automatically clean up after throwing an exception */ |
| class JPEGAutoClean { |
| public: |
| JPEGAutoClean(): cinfo_ptr(NULL) {} |
| ~JPEGAutoClean() { |
| if (cinfo_ptr) { |
| jpeg_destroy_decompress(cinfo_ptr); |
| } |
| } |
| void set(jpeg_decompress_struct* info) { |
| cinfo_ptr = info; |
| } |
| private: |
| jpeg_decompress_struct* cinfo_ptr; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| /* If we need to better match the request, we might examine the image and |
| output dimensions, and determine if the downsampling jpeg provided is |
| not sufficient. If so, we can recompute a modified sampleSize value to |
| make up the difference. |
| |
| To skip this additional scaling, just set sampleSize = 1; below. |
| */ |
| static int recompute_sampleSize(int sampleSize, |
| const jpeg_decompress_struct& cinfo) { |
| return sampleSize * cinfo.output_width / cinfo.image_width; |
| } |
| |
| static bool valid_output_dimensions(const jpeg_decompress_struct& cinfo) { |
| /* These are initialized to 0, so if they have non-zero values, we assume |
| they are "valid" (i.e. have been computed by libjpeg) |
| */ |
| return 0 != cinfo.output_width && 0 != cinfo.output_height; |
| } |
| |
| static bool skip_src_rows(jpeg_decompress_struct* cinfo, void* buffer, int count) { |
| for (int i = 0; i < count; i++) { |
| JSAMPLE* rowptr = (JSAMPLE*)buffer; |
| int row_count = jpeg_read_scanlines(cinfo, &rowptr, 1); |
| if (1 != row_count) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| #ifdef SK_BUILD_FOR_ANDROID |
| static bool skip_src_rows_tile(jpeg_decompress_struct* cinfo, |
| huffman_index *index, void* buffer, int count) { |
| for (int i = 0; i < count; i++) { |
| JSAMPLE* rowptr = (JSAMPLE*)buffer; |
| int row_count = jpeg_read_tile_scanline(cinfo, index, &rowptr); |
| if (1 != row_count) { |
| return false; |
| } |
| } |
| return true; |
| } |
| #endif |
| |
| // This guy exists just to aid in debugging, as it allows debuggers to just |
| // set a break-point in one place to see all error exists. |
| static bool return_false(const jpeg_decompress_struct& cinfo, |
| const SkBitmap& bm, const char caller[]) { |
| if (!(c_suppressJPEGImageDecoderErrors)) { |
| char buffer[JMSG_LENGTH_MAX]; |
| cinfo.err->format_message((const j_common_ptr)&cinfo, buffer); |
| SkDebugf("libjpeg error %d <%s> from %s [%d %d]\n", |
| cinfo.err->msg_code, buffer, caller, bm.width(), bm.height()); |
| } |
| return false; // must always return false |
| } |
| |
| // Convert a scanline of CMYK samples to RGBX in place. Note that this |
| // method moves the "scanline" pointer in its processing |
| static void convert_CMYK_to_RGB(uint8_t* scanline, unsigned int width) { |
| // At this point we've received CMYK pixels from libjpeg. We |
| // perform a crude conversion to RGB (based on the formulae |
| // from easyrgb.com): |
| // CMYK -> CMY |
| // C = ( C * (1 - K) + K ) // for each CMY component |
| // CMY -> RGB |
| // R = ( 1 - C ) * 255 // for each RGB component |
| // Unfortunately we are seeing inverted CMYK so all the original terms |
| // are 1-. This yields: |
| // CMYK -> CMY |
| // C = ( (1-C) * (1 - (1-K) + (1-K) ) -> C = 1 - C*K |
| // The conversion from CMY->RGB remains the same |
| for (unsigned int x = 0; x < width; ++x, scanline += 4) { |
| scanline[0] = SkMulDiv255Round(scanline[0], scanline[3]); |
| scanline[1] = SkMulDiv255Round(scanline[1], scanline[3]); |
| scanline[2] = SkMulDiv255Round(scanline[2], scanline[3]); |
| scanline[3] = 255; |
| } |
| } |
| |
| /** |
| * Common code for setting the error manager. |
| */ |
| static void set_error_mgr(jpeg_decompress_struct* cinfo, skjpeg_error_mgr* errorManager) { |
| SkASSERT(cinfo != NULL); |
| SkASSERT(errorManager != NULL); |
| cinfo->err = jpeg_std_error(errorManager); |
| errorManager->error_exit = skjpeg_error_exit; |
| } |
| |
| /** |
| * Common code for turning off upsampling and smoothing. Turning these |
| * off helps performance without showing noticable differences in the |
| * resulting bitmap. |
| */ |
| static void turn_off_visual_optimizations(jpeg_decompress_struct* cinfo) { |
| SkASSERT(cinfo != NULL); |
| /* this gives about 30% performance improvement. In theory it may |
| reduce the visual quality, in practice I'm not seeing a difference |
| */ |
| cinfo->do_fancy_upsampling = 0; |
| |
| /* this gives another few percents */ |
| cinfo->do_block_smoothing = 0; |
| } |
| |
| /** |
| * Common code for setting the dct method. |
| */ |
| static void set_dct_method(const SkImageDecoder& decoder, jpeg_decompress_struct* cinfo) { |
| SkASSERT(cinfo != NULL); |
| #ifdef DCT_IFAST_SUPPORTED |
| if (decoder.getPreferQualityOverSpeed()) { |
| cinfo->dct_method = JDCT_ISLOW; |
| } else { |
| cinfo->dct_method = JDCT_IFAST; |
| } |
| #else |
| cinfo->dct_method = JDCT_ISLOW; |
| #endif |
| } |
| |
| SkBitmap::Config SkJPEGImageDecoder::getBitmapConfig(jpeg_decompress_struct* cinfo) { |
| SkASSERT(cinfo != NULL); |
| |
| SrcDepth srcDepth = k32Bit_SrcDepth; |
| if (JCS_GRAYSCALE == cinfo->jpeg_color_space) { |
| srcDepth = k8BitGray_SrcDepth; |
| } |
| |
| SkBitmap::Config config = this->getPrefConfig(srcDepth, /*hasAlpha*/ false); |
| switch (config) { |
| case SkBitmap::kA8_Config: |
| // Only respect A8 config if the original is grayscale, |
| // in which case we will treat the grayscale as alpha |
| // values. |
| if (cinfo->jpeg_color_space != JCS_GRAYSCALE) { |
| config = SkBitmap::kARGB_8888_Config; |
| } |
| break; |
| case SkBitmap::kARGB_8888_Config: |
| // Fall through. |
| case SkBitmap::kARGB_4444_Config: |
| // Fall through. |
| case SkBitmap::kRGB_565_Config: |
| // These are acceptable destination configs. |
| break; |
| default: |
| // Force all other configs to 8888. |
| config = SkBitmap::kARGB_8888_Config; |
| break; |
| } |
| |
| switch (cinfo->jpeg_color_space) { |
| case JCS_CMYK: |
| // Fall through. |
| case JCS_YCCK: |
| // libjpeg cannot convert from CMYK or YCCK to RGB - here we set up |
| // so libjpeg will give us CMYK samples back and we will later |
| // manually convert them to RGB |
| cinfo->out_color_space = JCS_CMYK; |
| break; |
| case JCS_GRAYSCALE: |
| if (SkBitmap::kA8_Config == config) { |
| cinfo->out_color_space = JCS_GRAYSCALE; |
| break; |
| } |
| // The data is JCS_GRAYSCALE, but the caller wants some sort of RGB |
| // config. Fall through to set to the default. |
| default: |
| cinfo->out_color_space = JCS_RGB; |
| break; |
| } |
| return config; |
| } |
| |
| #ifdef ANDROID_RGB |
| /** |
| * Based on the config and dither mode, adjust out_color_space and |
| * dither_mode of cinfo. |
| */ |
| static void adjust_out_color_space_and_dither(jpeg_decompress_struct* cinfo, |
| SkBitmap::Config config, |
| const SkImageDecoder& decoder) { |
| SkASSERT(cinfo != NULL); |
| cinfo->dither_mode = JDITHER_NONE; |
| if (JCS_CMYK == cinfo->out_color_space) { |
| return; |
| } |
| switch(config) { |
| case SkBitmap::kARGB_8888_Config: |
| cinfo->out_color_space = JCS_RGBA_8888; |
| break; |
| case SkBitmap::kRGB_565_Config: |
| cinfo->out_color_space = JCS_RGB_565; |
| if (decoder.getDitherImage()) { |
| cinfo->dither_mode = JDITHER_ORDERED; |
| } |
| break; |
| default: |
| break; |
| } |
| } |
| #endif |
| |
| |
| /** |
| Sets all pixels in given bitmap to SK_ColorWHITE for all rows >= y. |
| Used when decoding fails partway through reading scanlines to fill |
| remaining lines. */ |
| static void fill_below_level(int y, SkBitmap* bitmap) { |
| SkIRect rect = SkIRect::MakeLTRB(0, y, bitmap->width(), bitmap->height()); |
| SkCanvas canvas(*bitmap); |
| canvas.clipRect(SkRect::Make(rect)); |
| canvas.drawColor(SK_ColorWHITE); |
| } |
| |
| /** |
| * Get the config and bytes per pixel of the source data. Return |
| * whether the data is supported. |
| */ |
| static bool get_src_config(const jpeg_decompress_struct& cinfo, |
| SkScaledBitmapSampler::SrcConfig* sc, |
| int* srcBytesPerPixel) { |
| SkASSERT(sc != NULL && srcBytesPerPixel != NULL); |
| if (JCS_CMYK == cinfo.out_color_space) { |
| // In this case we will manually convert the CMYK values to RGB |
| *sc = SkScaledBitmapSampler::kRGBX; |
| // The CMYK work-around relies on 4 components per pixel here |
| *srcBytesPerPixel = 4; |
| } else if (3 == cinfo.out_color_components && JCS_RGB == cinfo.out_color_space) { |
| *sc = SkScaledBitmapSampler::kRGB; |
| *srcBytesPerPixel = 3; |
| #ifdef ANDROID_RGB |
| } else if (JCS_RGBA_8888 == cinfo.out_color_space) { |
| *sc = SkScaledBitmapSampler::kRGBX; |
| *srcBytesPerPixel = 4; |
| } else if (JCS_RGB_565 == cinfo.out_color_space) { |
| *sc = SkScaledBitmapSampler::kRGB_565; |
| *srcBytesPerPixel = 2; |
| #endif |
| } else if (1 == cinfo.out_color_components && |
| JCS_GRAYSCALE == cinfo.out_color_space) { |
| *sc = SkScaledBitmapSampler::kGray; |
| *srcBytesPerPixel = 1; |
| } else { |
| return false; |
| } |
| return true; |
| } |
| |
| bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) { |
| #ifdef TIME_DECODE |
| SkAutoTime atm("JPEG Decode"); |
| #endif |
| |
| JPEGAutoClean autoClean; |
| |
| jpeg_decompress_struct cinfo; |
| skjpeg_source_mgr srcManager(stream, this); |
| |
| skjpeg_error_mgr errorManager; |
| set_error_mgr(&cinfo, &errorManager); |
| |
| // All objects need to be instantiated before this setjmp call so that |
| // they will be cleaned up properly if an error occurs. |
| if (setjmp(errorManager.fJmpBuf)) { |
| return return_false(cinfo, *bm, "setjmp"); |
| } |
| |
| initialize_info(&cinfo, &srcManager); |
| autoClean.set(&cinfo); |
| |
| int status = jpeg_read_header(&cinfo, true); |
| if (status != JPEG_HEADER_OK) { |
| return return_false(cinfo, *bm, "read_header"); |
| } |
| |
| /* Try to fulfill the requested sampleSize. Since jpeg can do it (when it |
| can) much faster that we, just use their num/denom api to approximate |
| the size. |
| */ |
| int sampleSize = this->getSampleSize(); |
| |
| set_dct_method(*this, &cinfo); |
| |
| SkASSERT(1 == cinfo.scale_num); |
| cinfo.scale_denom = sampleSize; |
| |
| turn_off_visual_optimizations(&cinfo); |
| |
| const SkBitmap::Config config = this->getBitmapConfig(&cinfo); |
| |
| #ifdef ANDROID_RGB |
| adjust_out_color_space_and_dither(&cinfo, config, *this); |
| #endif |
| |
| if (1 == sampleSize && SkImageDecoder::kDecodeBounds_Mode == mode) { |
| // Assume an A8 bitmap is not opaque to avoid the check of each |
| // individual pixel. It is very unlikely to be opaque, since |
| // an opaque A8 bitmap would not be very interesting. |
| // Otherwise, a jpeg image is opaque. |
| return bm->setConfig(config, cinfo.image_width, cinfo.image_height, 0, |
| SkBitmap::kA8_Config == config ? |
| kPremul_SkAlphaType : kOpaque_SkAlphaType); |
| } |
| |
| /* image_width and image_height are the original dimensions, available |
| after jpeg_read_header(). To see the scaled dimensions, we have to call |
| jpeg_start_decompress(), and then read output_width and output_height. |
| */ |
| if (!jpeg_start_decompress(&cinfo)) { |
| /* If we failed here, we may still have enough information to return |
| to the caller if they just wanted (subsampled bounds). If sampleSize |
| was 1, then we would have already returned. Thus we just check if |
| we're in kDecodeBounds_Mode, and that we have valid output sizes. |
| |
| One reason to fail here is that we have insufficient stream data |
| to complete the setup. However, output dimensions seem to get |
| computed very early, which is why this special check can pay off. |
| */ |
| if (SkImageDecoder::kDecodeBounds_Mode == mode && valid_output_dimensions(cinfo)) { |
| SkScaledBitmapSampler smpl(cinfo.output_width, cinfo.output_height, |
| recompute_sampleSize(sampleSize, cinfo)); |
| // Assume an A8 bitmap is not opaque to avoid the check of each |
| // individual pixel. It is very unlikely to be opaque, since |
| // an opaque A8 bitmap would not be very interesting. |
| // Otherwise, a jpeg image is opaque. |
| return bm->setConfig(config, smpl.scaledWidth(), smpl.scaledHeight(), |
| 0, SkBitmap::kA8_Config == config ? |
| kPremul_SkAlphaType : kOpaque_SkAlphaType); |
| } else { |
| return return_false(cinfo, *bm, "start_decompress"); |
| } |
| } |
| sampleSize = recompute_sampleSize(sampleSize, cinfo); |
| |
| // should we allow the Chooser (if present) to pick a config for us??? |
| if (!this->chooseFromOneChoice(config, cinfo.output_width, cinfo.output_height)) { |
| return return_false(cinfo, *bm, "chooseFromOneChoice"); |
| } |
| |
| SkScaledBitmapSampler sampler(cinfo.output_width, cinfo.output_height, sampleSize); |
| // Assume an A8 bitmap is not opaque to avoid the check of each |
| // individual pixel. It is very unlikely to be opaque, since |
| // an opaque A8 bitmap would not be very interesting. |
| // Otherwise, a jpeg image is opaque. |
| bm->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight(), 0, |
| SkBitmap::kA8_Config != config ? kOpaque_SkAlphaType : kPremul_SkAlphaType); |
| if (SkImageDecoder::kDecodeBounds_Mode == mode) { |
| return true; |
| } |
| if (!this->allocPixelRef(bm, NULL)) { |
| return return_false(cinfo, *bm, "allocPixelRef"); |
| } |
| |
| SkAutoLockPixels alp(*bm); |
| |
| #ifdef ANDROID_RGB |
| /* short-circuit the SkScaledBitmapSampler when possible, as this gives |
| a significant performance boost. |
| */ |
| if (sampleSize == 1 && |
| ((config == SkBitmap::kARGB_8888_Config && |
| cinfo.out_color_space == JCS_RGBA_8888) || |
| (config == SkBitmap::kRGB_565_Config && |
| cinfo.out_color_space == JCS_RGB_565))) |
| { |
| JSAMPLE* rowptr = (JSAMPLE*)bm->getPixels(); |
| INT32 const bpr = bm->rowBytes(); |
| |
| while (cinfo.output_scanline < cinfo.output_height) { |
| int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1); |
| if (0 == row_count) { |
| // if row_count == 0, then we didn't get a scanline, |
| // so return early. We will return a partial image. |
| fill_below_level(cinfo.output_scanline, bm); |
| cinfo.output_scanline = cinfo.output_height; |
| break; // Skip to jpeg_finish_decompress() |
| } |
| if (this->shouldCancelDecode()) { |
| return return_false(cinfo, *bm, "shouldCancelDecode"); |
| } |
| rowptr += bpr; |
| } |
| jpeg_finish_decompress(&cinfo); |
| return true; |
| } |
| #endif |
| |
| // check for supported formats |
| SkScaledBitmapSampler::SrcConfig sc; |
| int srcBytesPerPixel; |
| |
| if (!get_src_config(cinfo, &sc, &srcBytesPerPixel)) { |
| return return_false(cinfo, *bm, "jpeg colorspace"); |
| } |
| |
| if (!sampler.begin(bm, sc, *this)) { |
| return return_false(cinfo, *bm, "sampler.begin"); |
| } |
| |
| SkAutoMalloc srcStorage(cinfo.output_width * srcBytesPerPixel); |
| uint8_t* srcRow = (uint8_t*)srcStorage.get(); |
| |
| // Possibly skip initial rows [sampler.srcY0] |
| if (!skip_src_rows(&cinfo, srcRow, sampler.srcY0())) { |
| return return_false(cinfo, *bm, "skip rows"); |
| } |
| |
| // now loop through scanlines until y == bm->height() - 1 |
| for (int y = 0;; y++) { |
| JSAMPLE* rowptr = (JSAMPLE*)srcRow; |
| int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1); |
| if (0 == row_count) { |
| // if row_count == 0, then we didn't get a scanline, |
| // so return early. We will return a partial image. |
| fill_below_level(y, bm); |
| cinfo.output_scanline = cinfo.output_height; |
| break; // Skip to jpeg_finish_decompress() |
| } |
| if (this->shouldCancelDecode()) { |
| return return_false(cinfo, *bm, "shouldCancelDecode"); |
| } |
| |
| if (JCS_CMYK == cinfo.out_color_space) { |
| convert_CMYK_to_RGB(srcRow, cinfo.output_width); |
| } |
| |
| sampler.next(srcRow); |
| if (bm->height() - 1 == y) { |
| // we're done |
| break; |
| } |
| |
| if (!skip_src_rows(&cinfo, srcRow, sampler.srcDY() - 1)) { |
| return return_false(cinfo, *bm, "skip rows"); |
| } |
| } |
| |
| // we formally skip the rest, so we don't get a complaint from libjpeg |
| if (!skip_src_rows(&cinfo, srcRow, |
| cinfo.output_height - cinfo.output_scanline)) { |
| return return_false(cinfo, *bm, "skip rows"); |
| } |
| jpeg_finish_decompress(&cinfo); |
| |
| return true; |
| } |
| |
| #ifdef SK_BUILD_FOR_ANDROID |
| bool SkJPEGImageDecoder::onBuildTileIndex(SkStreamRewindable* stream, int *width, int *height) { |
| |
| SkAutoTDelete<SkJPEGImageIndex> imageIndex(SkNEW_ARGS(SkJPEGImageIndex, (stream, this))); |
| jpeg_decompress_struct* cinfo = imageIndex->cinfo(); |
| |
| skjpeg_error_mgr sk_err; |
| set_error_mgr(cinfo, &sk_err); |
| |
| // All objects need to be instantiated before this setjmp call so that |
| // they will be cleaned up properly if an error occurs. |
| if (setjmp(sk_err.fJmpBuf)) { |
| return false; |
| } |
| |
| // create the cinfo used to create/build the huffmanIndex |
| if (!imageIndex->initializeInfoAndReadHeader()) { |
| return false; |
| } |
| |
| if (!imageIndex->buildHuffmanIndex()) { |
| return false; |
| } |
| |
| // destroy the cinfo used to create/build the huffman index |
| imageIndex->destroyInfo(); |
| |
| // Init decoder to image decode mode |
| if (!imageIndex->initializeInfoAndReadHeader()) { |
| return false; |
| } |
| |
| // FIXME: This sets cinfo->out_color_space, which we may change later |
| // based on the config in onDecodeSubset. This should be fine, since |
| // jpeg_init_read_tile_scanline will check out_color_space again after |
| // that change (when it calls jinit_color_deconverter). |
| (void) this->getBitmapConfig(cinfo); |
| |
| turn_off_visual_optimizations(cinfo); |
| |
| // instead of jpeg_start_decompress() we start a tiled decompress |
| if (!imageIndex->startTileDecompress()) { |
| return false; |
| } |
| |
| SkASSERT(1 == cinfo->scale_num); |
| fImageWidth = cinfo->output_width; |
| fImageHeight = cinfo->output_height; |
| |
| if (width) { |
| *width = fImageWidth; |
| } |
| if (height) { |
| *height = fImageHeight; |
| } |
| |
| SkDELETE(fImageIndex); |
| fImageIndex = imageIndex.detach(); |
| |
| return true; |
| } |
| |
| bool SkJPEGImageDecoder::onDecodeSubset(SkBitmap* bm, const SkIRect& region) { |
| if (NULL == fImageIndex) { |
| return false; |
| } |
| jpeg_decompress_struct* cinfo = fImageIndex->cinfo(); |
| |
| SkIRect rect = SkIRect::MakeWH(fImageWidth, fImageHeight); |
| if (!rect.intersect(region)) { |
| // If the requested region is entirely outside the image return false |
| return false; |
| } |
| |
| |
| skjpeg_error_mgr errorManager; |
| set_error_mgr(cinfo, &errorManager); |
| |
| if (setjmp(errorManager.fJmpBuf)) { |
| return false; |
| } |
| |
| int requestedSampleSize = this->getSampleSize(); |
| cinfo->scale_denom = requestedSampleSize; |
| |
| set_dct_method(*this, cinfo); |
| |
| const SkBitmap::Config config = this->getBitmapConfig(cinfo); |
| #ifdef ANDROID_RGB |
| adjust_out_color_space_and_dither(cinfo, config, *this); |
| #endif |
| |
| int startX = rect.fLeft; |
| int startY = rect.fTop; |
| int width = rect.width(); |
| int height = rect.height(); |
| |
| jpeg_init_read_tile_scanline(cinfo, fImageIndex->huffmanIndex(), |
| &startX, &startY, &width, &height); |
| int skiaSampleSize = recompute_sampleSize(requestedSampleSize, *cinfo); |
| int actualSampleSize = skiaSampleSize * (DCTSIZE / cinfo->min_DCT_scaled_size); |
| |
| SkScaledBitmapSampler sampler(width, height, skiaSampleSize); |
| |
| SkBitmap bitmap; |
| bitmap.setConfig(config, sampler.scaledWidth(), sampler.scaledHeight()); |
| // Assume an A8 bitmap is not opaque to avoid the check of each |
| // individual pixel. It is very unlikely to be opaque, since |
| // an opaque A8 bitmap would not be very interesting. |
| // Otherwise, a jpeg image is opaque. |
| bitmap.setConfig(config, sampler.scaledWidth(), sampler.scaledHeight(), 0, |
| config == SkBitmap::kA8_Config ? kPremul_SkAlphaType : |
| kOpaque_SkAlphaType); |
| |
| // Check ahead of time if the swap(dest, src) is possible or not. |
| // If yes, then we will stick to AllocPixelRef since it's cheaper with the |
| // swap happening. If no, then we will use alloc to allocate pixels to |
| // prevent garbage collection. |
| int w = rect.width() / actualSampleSize; |
| int h = rect.height() / actualSampleSize; |
| bool swapOnly = (rect == region) && bm->isNull() && |
| (w == bitmap.width()) && (h == bitmap.height()) && |
| ((startX - rect.x()) / actualSampleSize == 0) && |
| ((startY - rect.y()) / actualSampleSize == 0); |
| if (swapOnly) { |
| if (!this->allocPixelRef(&bitmap, NULL)) { |
| return return_false(*cinfo, bitmap, "allocPixelRef"); |
| } |
| } else { |
| if (!bitmap.allocPixels()) { |
| return return_false(*cinfo, bitmap, "allocPixels"); |
| } |
| } |
| |
| SkAutoLockPixels alp(bitmap); |
| |
| #ifdef ANDROID_RGB |
| /* short-circuit the SkScaledBitmapSampler when possible, as this gives |
| a significant performance boost. |
| */ |
| if (skiaSampleSize == 1 && |
| ((config == SkBitmap::kARGB_8888_Config && |
| cinfo->out_color_space == JCS_RGBA_8888) || |
| (config == SkBitmap::kRGB_565_Config && |
| cinfo->out_color_space == JCS_RGB_565))) |
| { |
| JSAMPLE* rowptr = (JSAMPLE*)bitmap.getPixels(); |
| INT32 const bpr = bitmap.rowBytes(); |
| int rowTotalCount = 0; |
| |
| while (rowTotalCount < height) { |
| int rowCount = jpeg_read_tile_scanline(cinfo, |
| fImageIndex->huffmanIndex(), |
| &rowptr); |
| // if rowCount == 0, then we didn't get a scanline, so abort. |
| // onDecodeSubset() relies on onBuildTileIndex(), which |
| // needs a complete image to succeed. |
| if (0 == rowCount) { |
| return return_false(*cinfo, bitmap, "read_scanlines"); |
| } |
| if (this->shouldCancelDecode()) { |
| return return_false(*cinfo, bitmap, "shouldCancelDecode"); |
| } |
| rowTotalCount += rowCount; |
| rowptr += bpr; |
| } |
| |
| if (swapOnly) { |
| bm->swap(bitmap); |
| } else { |
| cropBitmap(bm, &bitmap, actualSampleSize, region.x(), region.y(), |
| region.width(), region.height(), startX, startY); |
| } |
| return true; |
| } |
| #endif |
| |
| // check for supported formats |
| SkScaledBitmapSampler::SrcConfig sc; |
| int srcBytesPerPixel; |
| |
| if (!get_src_config(*cinfo, &sc, &srcBytesPerPixel)) { |
| return return_false(*cinfo, *bm, "jpeg colorspace"); |
| } |
| |
| if (!sampler.begin(&bitmap, sc, *this)) { |
| return return_false(*cinfo, bitmap, "sampler.begin"); |
| } |
| |
| SkAutoMalloc srcStorage(width * srcBytesPerPixel); |
| uint8_t* srcRow = (uint8_t*)srcStorage.get(); |
| |
| // Possibly skip initial rows [sampler.srcY0] |
| if (!skip_src_rows_tile(cinfo, fImageIndex->huffmanIndex(), srcRow, sampler.srcY0())) { |
| return return_false(*cinfo, bitmap, "skip rows"); |
| } |
| |
| // now loop through scanlines until y == bitmap->height() - 1 |
| for (int y = 0;; y++) { |
| JSAMPLE* rowptr = (JSAMPLE*)srcRow; |
| int row_count = jpeg_read_tile_scanline(cinfo, fImageIndex->huffmanIndex(), &rowptr); |
| // if row_count == 0, then we didn't get a scanline, so abort. |
| // onDecodeSubset() relies on onBuildTileIndex(), which |
| // needs a complete image to succeed. |
| if (0 == row_count) { |
| return return_false(*cinfo, bitmap, "read_scanlines"); |
| } |
| if (this->shouldCancelDecode()) { |
| return return_false(*cinfo, bitmap, "shouldCancelDecode"); |
| } |
| |
| if (JCS_CMYK == cinfo->out_color_space) { |
| convert_CMYK_to_RGB(srcRow, width); |
| } |
| |
| sampler.next(srcRow); |
| if (bitmap.height() - 1 == y) { |
| // we're done |
| break; |
| } |
| |
| if (!skip_src_rows_tile(cinfo, fImageIndex->huffmanIndex(), srcRow, |
| sampler.srcDY() - 1)) { |
| return return_false(*cinfo, bitmap, "skip rows"); |
| } |
| } |
| if (swapOnly) { |
| bm->swap(bitmap); |
| } else { |
| cropBitmap(bm, &bitmap, actualSampleSize, region.x(), region.y(), |
| region.width(), region.height(), startX, startY); |
| } |
| return true; |
| } |
| #endif |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| #include "SkColorPriv.h" |
| |
| // taken from jcolor.c in libjpeg |
| #if 0 // 16bit - precise but slow |
| #define CYR 19595 // 0.299 |
| #define CYG 38470 // 0.587 |
| #define CYB 7471 // 0.114 |
| |
| #define CUR -11059 // -0.16874 |
| #define CUG -21709 // -0.33126 |
| #define CUB 32768 // 0.5 |
| |
| #define CVR 32768 // 0.5 |
| #define CVG -27439 // -0.41869 |
| #define CVB -5329 // -0.08131 |
| |
| #define CSHIFT 16 |
| #else // 8bit - fast, slightly less precise |
| #define CYR 77 // 0.299 |
| #define CYG 150 // 0.587 |
| #define CYB 29 // 0.114 |
| |
| #define CUR -43 // -0.16874 |
| #define CUG -85 // -0.33126 |
| #define CUB 128 // 0.5 |
| |
| #define CVR 128 // 0.5 |
| #define CVG -107 // -0.41869 |
| #define CVB -21 // -0.08131 |
| |
| #define CSHIFT 8 |
| #endif |
| |
| static void rgb2yuv_32(uint8_t dst[], SkPMColor c) { |
| int r = SkGetPackedR32(c); |
| int g = SkGetPackedG32(c); |
| int b = SkGetPackedB32(c); |
| |
| int y = ( CYR*r + CYG*g + CYB*b ) >> CSHIFT; |
| int u = ( CUR*r + CUG*g + CUB*b ) >> CSHIFT; |
| int v = ( CVR*r + CVG*g + CVB*b ) >> CSHIFT; |
| |
| dst[0] = SkToU8(y); |
| dst[1] = SkToU8(u + 128); |
| dst[2] = SkToU8(v + 128); |
| } |
| |
| static void rgb2yuv_4444(uint8_t dst[], U16CPU c) { |
| int r = SkGetPackedR4444(c); |
| int g = SkGetPackedG4444(c); |
| int b = SkGetPackedB4444(c); |
| |
| int y = ( CYR*r + CYG*g + CYB*b ) >> (CSHIFT - 4); |
| int u = ( CUR*r + CUG*g + CUB*b ) >> (CSHIFT - 4); |
| int v = ( CVR*r + CVG*g + CVB*b ) >> (CSHIFT - 4); |
| |
| dst[0] = SkToU8(y); |
| dst[1] = SkToU8(u + 128); |
| dst[2] = SkToU8(v + 128); |
| } |
| |
| static void rgb2yuv_16(uint8_t dst[], U16CPU c) { |
| int r = SkGetPackedR16(c); |
| int g = SkGetPackedG16(c); |
| int b = SkGetPackedB16(c); |
| |
| int y = ( 2*CYR*r + CYG*g + 2*CYB*b ) >> (CSHIFT - 2); |
| int u = ( 2*CUR*r + CUG*g + 2*CUB*b ) >> (CSHIFT - 2); |
| int v = ( 2*CVR*r + CVG*g + 2*CVB*b ) >> (CSHIFT - 2); |
| |
| dst[0] = SkToU8(y); |
| dst[1] = SkToU8(u + 128); |
| dst[2] = SkToU8(v + 128); |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| typedef void (*WriteScanline)(uint8_t* SK_RESTRICT dst, |
| const void* SK_RESTRICT src, int width, |
| const SkPMColor* SK_RESTRICT ctable); |
| |
| static void Write_32_YUV(uint8_t* SK_RESTRICT dst, |
| const void* SK_RESTRICT srcRow, int width, |
| const SkPMColor*) { |
| const uint32_t* SK_RESTRICT src = (const uint32_t*)srcRow; |
| while (--width >= 0) { |
| #ifdef WE_CONVERT_TO_YUV |
| rgb2yuv_32(dst, *src++); |
| #else |
| uint32_t c = *src++; |
| dst[0] = SkGetPackedR32(c); |
| dst[1] = SkGetPackedG32(c); |
| dst[2] = SkGetPackedB32(c); |
| #endif |
| dst += 3; |
| } |
| } |
| |
| static void Write_4444_YUV(uint8_t* SK_RESTRICT dst, |
| const void* SK_RESTRICT srcRow, int width, |
| const SkPMColor*) { |
| const SkPMColor16* SK_RESTRICT src = (const SkPMColor16*)srcRow; |
| while (--width >= 0) { |
| #ifdef WE_CONVERT_TO_YUV |
| rgb2yuv_4444(dst, *src++); |
| #else |
| SkPMColor16 c = *src++; |
| dst[0] = SkPacked4444ToR32(c); |
| dst[1] = SkPacked4444ToG32(c); |
| dst[2] = SkPacked4444ToB32(c); |
| #endif |
| dst += 3; |
| } |
| } |
| |
| static void Write_16_YUV(uint8_t* SK_RESTRICT dst, |
| const void* SK_RESTRICT srcRow, int width, |
| const SkPMColor*) { |
| const uint16_t* SK_RESTRICT src = (const uint16_t*)srcRow; |
| while (--width >= 0) { |
| #ifdef WE_CONVERT_TO_YUV |
| rgb2yuv_16(dst, *src++); |
| #else |
| uint16_t c = *src++; |
| dst[0] = SkPacked16ToR32(c); |
| dst[1] = SkPacked16ToG32(c); |
| dst[2] = SkPacked16ToB32(c); |
| #endif |
| dst += 3; |
| } |
| } |
| |
| static void Write_Index_YUV(uint8_t* SK_RESTRICT dst, |
| const void* SK_RESTRICT srcRow, int width, |
| const SkPMColor* SK_RESTRICT ctable) { |
| const uint8_t* SK_RESTRICT src = (const uint8_t*)srcRow; |
| while (--width >= 0) { |
| #ifdef WE_CONVERT_TO_YUV |
| rgb2yuv_32(dst, ctable[*src++]); |
| #else |
| uint32_t c = ctable[*src++]; |
| dst[0] = SkGetPackedR32(c); |
| dst[1] = SkGetPackedG32(c); |
| dst[2] = SkGetPackedB32(c); |
| #endif |
| dst += 3; |
| } |
| } |
| |
| static WriteScanline ChooseWriter(const SkBitmap& bm) { |
| switch (bm.config()) { |
| case SkBitmap::kARGB_8888_Config: |
| return Write_32_YUV; |
| case SkBitmap::kRGB_565_Config: |
| return Write_16_YUV; |
| case SkBitmap::kARGB_4444_Config: |
| return Write_4444_YUV; |
| case SkBitmap::kIndex8_Config: |
| return Write_Index_YUV; |
| default: |
| return NULL; |
| } |
| } |
| |
| class SkJPEGImageEncoder : public SkImageEncoder { |
| protected: |
| virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality) { |
| #ifdef TIME_ENCODE |
| SkAutoTime atm("JPEG Encode"); |
| #endif |
| |
| SkAutoLockPixels alp(bm); |
| if (NULL == bm.getPixels()) { |
| return false; |
| } |
| |
| jpeg_compress_struct cinfo; |
| skjpeg_error_mgr sk_err; |
| skjpeg_destination_mgr sk_wstream(stream); |
| |
| // allocate these before set call setjmp |
| SkAutoMalloc oneRow; |
| SkAutoLockColors ctLocker; |
| |
| cinfo.err = jpeg_std_error(&sk_err); |
| sk_err.error_exit = skjpeg_error_exit; |
| if (setjmp(sk_err.fJmpBuf)) { |
| return false; |
| } |
| |
| // Keep after setjmp or mark volatile. |
| const WriteScanline writer = ChooseWriter(bm); |
| if (NULL == writer) { |
| return false; |
| } |
| |
| jpeg_create_compress(&cinfo); |
| cinfo.dest = &sk_wstream; |
| cinfo.image_width = bm.width(); |
| cinfo.image_height = bm.height(); |
| cinfo.input_components = 3; |
| #ifdef WE_CONVERT_TO_YUV |
| cinfo.in_color_space = JCS_YCbCr; |
| #else |
| cinfo.in_color_space = JCS_RGB; |
| #endif |
| cinfo.input_gamma = 1; |
| |
| jpeg_set_defaults(&cinfo); |
| jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */); |
| #ifdef DCT_IFAST_SUPPORTED |
| cinfo.dct_method = JDCT_IFAST; |
| #endif |
| |
| jpeg_start_compress(&cinfo, TRUE); |
| |
| const int width = bm.width(); |
| uint8_t* oneRowP = (uint8_t*)oneRow.reset(width * 3); |
| |
| const SkPMColor* colors = ctLocker.lockColors(bm); |
| const void* srcRow = bm.getPixels(); |
| |
| while (cinfo.next_scanline < cinfo.image_height) { |
| JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */ |
| |
| writer(oneRowP, srcRow, width, colors); |
| row_pointer[0] = oneRowP; |
| (void) jpeg_write_scanlines(&cinfo, row_pointer, 1); |
| srcRow = (const void*)((const char*)srcRow + bm.rowBytes()); |
| } |
| |
| jpeg_finish_compress(&cinfo); |
| jpeg_destroy_compress(&cinfo); |
| |
| return true; |
| } |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| DEFINE_DECODER_CREATOR(JPEGImageDecoder); |
| DEFINE_ENCODER_CREATOR(JPEGImageEncoder); |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| static bool is_jpeg(SkStreamRewindable* stream) { |
| static const unsigned char gHeader[] = { 0xFF, 0xD8, 0xFF }; |
| static const size_t HEADER_SIZE = sizeof(gHeader); |
| |
| char buffer[HEADER_SIZE]; |
| size_t len = stream->read(buffer, HEADER_SIZE); |
| |
| if (len != HEADER_SIZE) { |
| return false; // can't read enough |
| } |
| if (memcmp(buffer, gHeader, HEADER_SIZE)) { |
| return false; |
| } |
| return true; |
| } |
| |
| |
| static SkImageDecoder* sk_libjpeg_dfactory(SkStreamRewindable* stream) { |
| if (is_jpeg(stream)) { |
| return SkNEW(SkJPEGImageDecoder); |
| } |
| return NULL; |
| } |
| |
| static SkImageDecoder::Format get_format_jpeg(SkStreamRewindable* stream) { |
| if (is_jpeg(stream)) { |
| return SkImageDecoder::kJPEG_Format; |
| } |
| return SkImageDecoder::kUnknown_Format; |
| } |
| |
| static SkImageEncoder* sk_libjpeg_efactory(SkImageEncoder::Type t) { |
| return (SkImageEncoder::kJPEG_Type == t) ? SkNEW(SkJPEGImageEncoder) : NULL; |
| } |
| |
| static SkImageDecoder_DecodeReg gDReg(sk_libjpeg_dfactory); |
| static SkImageDecoder_FormatReg gFormatReg(get_format_jpeg); |
| static SkImageEncoder_EncodeReg gEReg(sk_libjpeg_efactory); |