| /* |
| * Copyright 2015 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkCodec.h" |
| #include "SkJpegCodec.h" |
| #include "SkJpegDecoderMgr.h" |
| #include "SkJpegUtility_codec.h" |
| #include "SkCodecPriv.h" |
| #include "SkColorPriv.h" |
| #include "SkStream.h" |
| #include "SkTemplates.h" |
| #include "SkTypes.h" |
| |
| // stdio is needed for libjpeg-turbo |
| #include <stdio.h> |
| |
| extern "C" { |
| #include "jerror.h" |
| #include "jpeglib.h" |
| } |
| |
| bool SkJpegCodec::IsJpeg(const void* buffer, size_t bytesRead) { |
| static const uint8_t jpegSig[] = { 0xFF, 0xD8, 0xFF }; |
| return bytesRead >= 3 && !memcmp(buffer, jpegSig, sizeof(jpegSig)); |
| } |
| |
| bool SkJpegCodec::ReadHeader(SkStream* stream, SkCodec** codecOut, |
| JpegDecoderMgr** decoderMgrOut) { |
| |
| // Create a JpegDecoderMgr to own all of the decompress information |
| SkAutoTDelete<JpegDecoderMgr> decoderMgr(new JpegDecoderMgr(stream)); |
| |
| // libjpeg errors will be caught and reported here |
| if (setjmp(decoderMgr->getJmpBuf())) { |
| return decoderMgr->returnFalse("setjmp"); |
| } |
| |
| // Initialize the decompress info and the source manager |
| decoderMgr->init(); |
| |
| // Read the jpeg header |
| if (JPEG_HEADER_OK != jpeg_read_header(decoderMgr->dinfo(), true)) { |
| return decoderMgr->returnFalse("read_header"); |
| } |
| |
| if (nullptr != codecOut) { |
| // Recommend the color type to decode to |
| const SkColorType colorType = decoderMgr->getColorType(); |
| |
| // Create image info object and the codec |
| const SkImageInfo& imageInfo = SkImageInfo::Make(decoderMgr->dinfo()->image_width, |
| decoderMgr->dinfo()->image_height, colorType, kOpaque_SkAlphaType); |
| *codecOut = new SkJpegCodec(imageInfo, stream, decoderMgr.detach()); |
| } else { |
| SkASSERT(nullptr != decoderMgrOut); |
| *decoderMgrOut = decoderMgr.detach(); |
| } |
| return true; |
| } |
| |
| SkCodec* SkJpegCodec::NewFromStream(SkStream* stream) { |
| SkAutoTDelete<SkStream> streamDeleter(stream); |
| SkCodec* codec = nullptr; |
| if (ReadHeader(stream, &codec, nullptr)) { |
| // Codec has taken ownership of the stream, we do not need to delete it |
| SkASSERT(codec); |
| streamDeleter.detach(); |
| return codec; |
| } |
| return nullptr; |
| } |
| |
| SkJpegCodec::SkJpegCodec(const SkImageInfo& srcInfo, SkStream* stream, |
| JpegDecoderMgr* decoderMgr) |
| : INHERITED(srcInfo, stream) |
| , fDecoderMgr(decoderMgr) |
| , fReadyState(decoderMgr->dinfo()->global_state) |
| {} |
| |
| /* |
| * Return the row bytes of a particular image type and width |
| */ |
| static int get_row_bytes(const j_decompress_ptr dinfo) { |
| int colorBytes = (dinfo->out_color_space == JCS_RGB565) ? 2 : dinfo->out_color_components; |
| return dinfo->output_width * colorBytes; |
| |
| } |
| |
| /* |
| * Calculate output dimensions based on the provided factors. |
| * |
| * Not to be used on the actual jpeg_decompress_struct used for decoding, since it will |
| * incorrectly modify num_components. |
| */ |
| void calc_output_dimensions(jpeg_decompress_struct* dinfo, unsigned int num, unsigned int denom) { |
| dinfo->num_components = 0; |
| dinfo->scale_num = num; |
| dinfo->scale_denom = denom; |
| jpeg_calc_output_dimensions(dinfo); |
| } |
| |
| /* |
| * Return a valid set of output dimensions for this decoder, given an input scale |
| */ |
| SkISize SkJpegCodec::onGetScaledDimensions(float desiredScale) const { |
| // libjpeg-turbo supports scaling by 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 7/8, and 1/1, so we will |
| // support these as well |
| unsigned int num; |
| unsigned int denom = 8; |
| if (desiredScale >= 0.9375) { |
| num = 8; |
| } else if (desiredScale >= 0.8125) { |
| num = 7; |
| } else if (desiredScale >= 0.6875f) { |
| num = 6; |
| } else if (desiredScale >= 0.5625f) { |
| num = 5; |
| } else if (desiredScale >= 0.4375f) { |
| num = 4; |
| } else if (desiredScale >= 0.3125f) { |
| num = 3; |
| } else if (desiredScale >= 0.1875f) { |
| num = 2; |
| } else { |
| num = 1; |
| } |
| |
| // Set up a fake decompress struct in order to use libjpeg to calculate output dimensions |
| jpeg_decompress_struct dinfo; |
| sk_bzero(&dinfo, sizeof(dinfo)); |
| dinfo.image_width = this->getInfo().width(); |
| dinfo.image_height = this->getInfo().height(); |
| dinfo.global_state = fReadyState; |
| calc_output_dimensions(&dinfo, num, denom); |
| |
| // Return the calculated output dimensions for the given scale |
| return SkISize::Make(dinfo.output_width, dinfo.output_height); |
| } |
| |
| bool SkJpegCodec::onRewind() { |
| JpegDecoderMgr* decoderMgr = nullptr; |
| if (!ReadHeader(this->stream(), nullptr, &decoderMgr)) { |
| return fDecoderMgr->returnFalse("could not rewind"); |
| } |
| SkASSERT(nullptr != decoderMgr); |
| fDecoderMgr.reset(decoderMgr); |
| return true; |
| } |
| |
| /* |
| * Checks if the conversion between the input image and the requested output |
| * image has been implemented |
| * Sets the output color space |
| */ |
| bool SkJpegCodec::setOutputColorSpace(const SkImageInfo& dst) { |
| const SkImageInfo& src = this->getInfo(); |
| |
| // Ensure that the profile type is unchanged |
| if (dst.profileType() != src.profileType()) { |
| return false; |
| } |
| |
| // Ensure that the alpha type is opaque |
| if (kOpaque_SkAlphaType != dst.alphaType()) { |
| return false; |
| } |
| |
| // Check if we will decode to CMYK because a conversion to RGBA is not supported |
| J_COLOR_SPACE colorSpace = fDecoderMgr->dinfo()->jpeg_color_space; |
| bool isCMYK = JCS_CMYK == colorSpace || JCS_YCCK == colorSpace; |
| |
| // Check for valid color types and set the output color space |
| switch (dst.colorType()) { |
| case kN32_SkColorType: |
| if (isCMYK) { |
| fDecoderMgr->dinfo()->out_color_space = JCS_CMYK; |
| } else { |
| // Check the byte ordering of the RGBA color space for the |
| // current platform |
| #if defined(SK_PMCOLOR_IS_RGBA) |
| fDecoderMgr->dinfo()->out_color_space = JCS_EXT_RGBA; |
| #else |
| fDecoderMgr->dinfo()->out_color_space = JCS_EXT_BGRA; |
| #endif |
| } |
| return true; |
| case kRGB_565_SkColorType: |
| if (isCMYK) { |
| fDecoderMgr->dinfo()->out_color_space = JCS_CMYK; |
| } else { |
| fDecoderMgr->dinfo()->dither_mode = JDITHER_NONE; |
| fDecoderMgr->dinfo()->out_color_space = JCS_RGB565; |
| } |
| return true; |
| case kGray_8_SkColorType: |
| if (isCMYK) { |
| return false; |
| } else { |
| // We will enable decodes to gray even if the image is color because this is |
| // much faster than decoding to color and then converting |
| fDecoderMgr->dinfo()->out_color_space = JCS_GRAYSCALE; |
| } |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| /* |
| * Checks if we can natively scale to the requested dimensions and natively scales the |
| * dimensions if possible |
| */ |
| bool SkJpegCodec::onDimensionsSupported(const SkISize& size) { |
| if (setjmp(fDecoderMgr->getJmpBuf())) { |
| return fDecoderMgr->returnFalse("onDimensionsSupported/setjmp"); |
| } |
| |
| const unsigned int dstWidth = size.width(); |
| const unsigned int dstHeight = size.height(); |
| |
| // Set up a fake decompress struct in order to use libjpeg to calculate output dimensions |
| // FIXME: Why is this necessary? |
| jpeg_decompress_struct dinfo; |
| sk_bzero(&dinfo, sizeof(dinfo)); |
| dinfo.image_width = this->getInfo().width(); |
| dinfo.image_height = this->getInfo().height(); |
| dinfo.global_state = fReadyState; |
| |
| // libjpeg-turbo can scale to 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 7/8, and 1/1 |
| unsigned int num = 8; |
| const unsigned int denom = 8; |
| calc_output_dimensions(&dinfo, num, denom); |
| while (dinfo.output_width != dstWidth || dinfo.output_height != dstHeight) { |
| |
| // Return a failure if we have tried all of the possible scales |
| if (1 == num || dstWidth > dinfo.output_width || dstHeight > dinfo.output_height) { |
| return false; |
| } |
| |
| // Try the next scale |
| num -= 1; |
| calc_output_dimensions(&dinfo, num, denom); |
| } |
| |
| fDecoderMgr->dinfo()->scale_num = num; |
| fDecoderMgr->dinfo()->scale_denom = denom; |
| return true; |
| } |
| |
| /* |
| * Performs the jpeg decode |
| */ |
| SkCodec::Result SkJpegCodec::onGetPixels(const SkImageInfo& dstInfo, |
| void* dst, size_t dstRowBytes, |
| const Options& options, SkPMColor*, int*, |
| int* rowsDecoded) { |
| if (options.fSubset) { |
| // Subsets are not supported. |
| return kUnimplemented; |
| } |
| |
| // Get a pointer to the decompress info since we will use it quite frequently |
| jpeg_decompress_struct* dinfo = fDecoderMgr->dinfo(); |
| |
| // Set the jump location for libjpeg errors |
| if (setjmp(fDecoderMgr->getJmpBuf())) { |
| return fDecoderMgr->returnFailure("setjmp", kInvalidInput); |
| } |
| |
| // Check if we can decode to the requested destination and set the output color space |
| if (!this->setOutputColorSpace(dstInfo)) { |
| return fDecoderMgr->returnFailure("conversion_possible", kInvalidConversion); |
| } |
| |
| // Now, given valid output dimensions, we can start the decompress |
| if (!jpeg_start_decompress(dinfo)) { |
| return fDecoderMgr->returnFailure("startDecompress", kInvalidInput); |
| } |
| |
| // The recommended output buffer height should always be 1 in high quality modes. |
| // If it's not, we want to know because it means our strategy is not optimal. |
| SkASSERT(1 == dinfo->rec_outbuf_height); |
| |
| if (JCS_CMYK == dinfo->out_color_space) { |
| this->initializeSwizzler(dstInfo, options); |
| } |
| |
| // Perform the decode a single row at a time |
| uint32_t dstHeight = dstInfo.height(); |
| |
| JSAMPLE* dstRow; |
| if (fSwizzler) { |
| // write data to storage row, then sample using swizzler |
| dstRow = fSrcRow; |
| } else { |
| // write data directly to dst |
| dstRow = (JSAMPLE*) dst; |
| } |
| |
| for (uint32_t y = 0; y < dstHeight; y++) { |
| // Read rows of the image |
| uint32_t lines = jpeg_read_scanlines(dinfo, &dstRow, 1); |
| |
| // If we cannot read enough rows, assume the input is incomplete |
| if (lines != 1) { |
| *rowsDecoded = y; |
| |
| return fDecoderMgr->returnFailure("Incomplete image data", kIncompleteInput); |
| } |
| |
| if (fSwizzler) { |
| // use swizzler to sample row |
| fSwizzler->swizzle(dst, dstRow); |
| dst = SkTAddOffset<JSAMPLE>(dst, dstRowBytes); |
| } else { |
| dstRow = SkTAddOffset<JSAMPLE>(dstRow, dstRowBytes); |
| } |
| } |
| |
| return kSuccess; |
| } |
| |
| void SkJpegCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Options& options) { |
| SkSwizzler::SrcConfig srcConfig = SkSwizzler::kUnknown; |
| if (JCS_CMYK == fDecoderMgr->dinfo()->out_color_space) { |
| srcConfig = SkSwizzler::kCMYK; |
| } else { |
| switch (dstInfo.colorType()) { |
| case kGray_8_SkColorType: |
| srcConfig = SkSwizzler::kGray; |
| break; |
| case kRGBA_8888_SkColorType: |
| srcConfig = SkSwizzler::kRGBX; |
| break; |
| case kBGRA_8888_SkColorType: |
| srcConfig = SkSwizzler::kBGRX; |
| break; |
| case kRGB_565_SkColorType: |
| srcConfig = SkSwizzler::kRGB_565; |
| break; |
| default: |
| // This function should only be called if the colorType is supported by jpeg |
| SkASSERT(false); |
| } |
| } |
| |
| fSwizzler.reset(SkSwizzler::CreateSwizzler(srcConfig, nullptr, dstInfo, options)); |
| fStorage.reset(get_row_bytes(fDecoderMgr->dinfo())); |
| fSrcRow = fStorage.get(); |
| } |
| |
| SkSampler* SkJpegCodec::getSampler(bool createIfNecessary) { |
| if (!createIfNecessary || fSwizzler) { |
| SkASSERT(!fSwizzler || (fSrcRow && fStorage.get() == fSrcRow)); |
| return fSwizzler; |
| } |
| |
| this->initializeSwizzler(this->dstInfo(), this->options()); |
| return fSwizzler; |
| } |
| |
| SkCodec::Result SkJpegCodec::onStartScanlineDecode(const SkImageInfo& dstInfo, |
| const Options& options, SkPMColor ctable[], int* ctableCount) { |
| // Set the jump location for libjpeg errors |
| if (setjmp(fDecoderMgr->getJmpBuf())) { |
| SkCodecPrintf("setjmp: Error from libjpeg\n"); |
| return kInvalidInput; |
| } |
| |
| // Check if we can decode to the requested destination and set the output color space |
| if (!this->setOutputColorSpace(dstInfo)) { |
| return kInvalidConversion; |
| } |
| |
| // Remove objects used for sampling. |
| fSwizzler.reset(nullptr); |
| fSrcRow = nullptr; |
| fStorage.free(); |
| |
| // Now, given valid output dimensions, we can start the decompress |
| if (!jpeg_start_decompress(fDecoderMgr->dinfo())) { |
| SkCodecPrintf("start decompress failed\n"); |
| return kInvalidInput; |
| } |
| |
| // We will need a swizzler if we are performing a subset decode or |
| // converting from CMYK. |
| if (options.fSubset || JCS_CMYK == fDecoderMgr->dinfo()->out_color_space) { |
| this->initializeSwizzler(dstInfo, options); |
| } |
| |
| return kSuccess; |
| } |
| |
| int SkJpegCodec::onGetScanlines(void* dst, int count, size_t rowBytes) { |
| // Set the jump location for libjpeg errors |
| if (setjmp(fDecoderMgr->getJmpBuf())) { |
| return fDecoderMgr->returnFailure("setjmp", kInvalidInput); |
| } |
| // Read rows one at a time |
| JSAMPLE* dstRow; |
| if (fSwizzler) { |
| // write data to storage row, then sample using swizzler |
| dstRow = fSrcRow; |
| } else { |
| // write data directly to dst |
| dstRow = (JSAMPLE*) dst; |
| } |
| |
| for (int y = 0; y < count; y++) { |
| // Read row of the image |
| uint32_t rowsDecoded = jpeg_read_scanlines(fDecoderMgr->dinfo(), &dstRow, 1); |
| if (rowsDecoded != 1) { |
| fDecoderMgr->dinfo()->output_scanline = this->dstInfo().height(); |
| return y; |
| } |
| |
| if (fSwizzler) { |
| // use swizzler to sample row |
| fSwizzler->swizzle(dst, dstRow); |
| dst = SkTAddOffset<JSAMPLE>(dst, rowBytes); |
| } else { |
| dstRow = SkTAddOffset<JSAMPLE>(dstRow, rowBytes); |
| } |
| } |
| return count; |
| } |
| |
| #ifndef TURBO_HAS_SKIP |
| // TODO (msarett): Avoid reallocating the memory buffer on each call to skip. |
| static uint32_t jpeg_skip_scanlines(jpeg_decompress_struct* dinfo, int count) { |
| SkAutoTMalloc<uint8_t> storage(get_row_bytes(dinfo)); |
| uint8_t* storagePtr = storage.get(); |
| for (int y = 0; y < count; y++) { |
| if (1 != jpeg_read_scanlines(dinfo, &storagePtr, 1)) { |
| return y; |
| } |
| } |
| return count; |
| } |
| #endif |
| |
| bool SkJpegCodec::onSkipScanlines(int count) { |
| // Set the jump location for libjpeg errors |
| if (setjmp(fDecoderMgr->getJmpBuf())) { |
| return fDecoderMgr->returnFalse("setjmp"); |
| } |
| |
| return (uint32_t) count == jpeg_skip_scanlines(fDecoderMgr->dinfo(), count); |
| } |
