| /* |
| * 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 "SkScaledCodec.h" |
| #include "SkScanlineDecoder.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" |
| } |
| |
| /* |
| * Convert a row of CMYK samples to RGBA in place. |
| * Note that this method moves the row pointer. |
| * @param width the number of pixels in the row that is being converted |
| * CMYK is stored as four bytes per pixel |
| */ |
| static void convert_CMYK_to_RGBA(uint8_t* row, uint32_t width) { |
| // We will implement a crude conversion from CMYK -> RGB using formulas |
| // from easyrgb.com. |
| // |
| // CMYK -> CMY |
| // C = C * (1 - K) + K |
| // M = M * (1 - K) + K |
| // Y = Y * (1 - K) + K |
| // |
| // libjpeg actually gives us inverted CMYK, so we must subtract the |
| // original terms from 1. |
| // CMYK -> CMY |
| // C = (1 - C) * (1 - (1 - K)) + (1 - K) |
| // M = (1 - M) * (1 - (1 - K)) + (1 - K) |
| // Y = (1 - Y) * (1 - (1 - K)) + (1 - K) |
| // |
| // Simplifying the above expression. |
| // CMYK -> CMY |
| // C = 1 - CK |
| // M = 1 - MK |
| // Y = 1 - YK |
| // |
| // CMY -> RGB |
| // R = (1 - C) * 255 |
| // G = (1 - M) * 255 |
| // B = (1 - Y) * 255 |
| // |
| // Therefore the full conversion is below. This can be verified at |
| // www.rapidtables.com (assuming inverted CMYK). |
| // CMYK -> RGB |
| // R = C * K * 255 |
| // G = M * K * 255 |
| // B = Y * K * 255 |
| // |
| // As a final note, we have treated the CMYK values as if they were on |
| // a scale from 0-1, when in fact they are 8-bit ints scaling from 0-255. |
| // We must divide each CMYK component by 255 to obtain the true conversion |
| // we should perform. |
| // CMYK -> RGB |
| // R = C * K / 255 |
| // G = M * K / 255 |
| // B = Y * K / 255 |
| for (uint32_t x = 0; x < width; x++, row += 4) { |
| #if defined(SK_PMCOLOR_IS_RGBA) |
| row[0] = SkMulDiv255Round(row[0], row[3]); |
| row[1] = SkMulDiv255Round(row[1], row[3]); |
| row[2] = SkMulDiv255Round(row[2], row[3]); |
| #else |
| uint8_t tmp = row[0]; |
| row[0] = SkMulDiv255Round(row[2], row[3]); |
| row[1] = SkMulDiv255Round(row[1], row[3]); |
| row[2] = SkMulDiv255Round(tmp, row[3]); |
| #endif |
| row[3] = 0xFF; |
| } |
| } |
| |
| bool SkJpegCodec::IsJpeg(SkStream* stream) { |
| static const uint8_t jpegSig[] = { 0xFF, 0xD8, 0xFF }; |
| char buffer[sizeof(jpegSig)]; |
| return stream->read(buffer, sizeof(jpegSig)) == sizeof(jpegSig) && |
| !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; |
| |
| } |
| /* |
| * 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 |
| long num; |
| long denom = 8; |
| if (desiredScale > 0.875f) { |
| num = 8; |
| } else if (desiredScale > 0.75f) { |
| num = 7; |
| } else if (desiredScale > 0.625f) { |
| num = 6; |
| } else if (desiredScale > 0.5f) { |
| num = 5; |
| } else if (desiredScale > 0.375f) { |
| num = 4; |
| } else if (desiredScale > 0.25f) { |
| num = 3; |
| } else if (desiredScale > 0.125f) { |
| 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; |
| dinfo.num_components = 0; |
| dinfo.scale_num = num; |
| dinfo.scale_denom = denom; |
| jpeg_calc_output_dimensions(&dinfo); |
| |
| // 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) { |
| return false; |
| } else { |
| 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::nativelyScaleToDimensions(uint32_t dstWidth, uint32_t dstHeight) { |
| // libjpeg-turbo can scale to 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 7/8, and 1/1 |
| fDecoderMgr->dinfo()->scale_denom = 8; |
| fDecoderMgr->dinfo()->scale_num = 8; |
| jpeg_calc_output_dimensions(fDecoderMgr->dinfo()); |
| while (fDecoderMgr->dinfo()->output_width != dstWidth || |
| fDecoderMgr->dinfo()->output_height != dstHeight) { |
| |
| // Return a failure if we have tried all of the possible scales |
| if (1 == fDecoderMgr->dinfo()->scale_num || |
| dstWidth > fDecoderMgr->dinfo()->output_width || |
| dstHeight > fDecoderMgr->dinfo()->output_height) { |
| // reset native scale settings on failure because this may be supported by the swizzler |
| this->fDecoderMgr->dinfo()->scale_num = 8; |
| jpeg_calc_output_dimensions(this->fDecoderMgr->dinfo()); |
| return false; |
| } |
| |
| // Try the next scale |
| fDecoderMgr->dinfo()->scale_num -= 1; |
| jpeg_calc_output_dimensions(fDecoderMgr->dinfo()); |
| } |
| return true; |
| } |
| |
| /* |
| * Performs the jpeg decode |
| */ |
| SkCodec::Result SkJpegCodec::onGetPixels(const SkImageInfo& dstInfo, |
| void* dst, size_t dstRowBytes, |
| const Options& options, SkPMColor*, int*) { |
| // Rewind the stream if needed |
| if (!this->rewindIfNeeded()) { |
| return fDecoderMgr->returnFailure("could not rewind stream", kCouldNotRewind); |
| } |
| |
| 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); |
| } |
| |
| // Perform the necessary scaling |
| if (!this->nativelyScaleToDimensions(dstInfo.width(), dstInfo.height())) { |
| return fDecoderMgr->returnFailure("cannot scale to requested dims", kInvalidScale); |
| } |
| |
| // 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); |
| |
| // Perform the decode a single row at a time |
| uint32_t dstHeight = dstInfo.height(); |
| JSAMPLE* dstRow = (JSAMPLE*) dst; |
| for (uint32_t y = 0; y < dstHeight; y++) { |
| // Read rows of the image |
| uint32_t rowsDecoded = jpeg_read_scanlines(dinfo, &dstRow, 1); |
| |
| // If we cannot read enough rows, assume the input is incomplete |
| if (rowsDecoded != 1) { |
| // Fill the remainder of the image with black. This error handling |
| // behavior is unspecified but SkCodec consistently uses black as |
| // the fill color for opaque images. If the destination is kGray, |
| // the low 8 bits of SK_ColorBLACK will be used. Conveniently, |
| // these are zeros, which is the representation for black in kGray. |
| // If the destination is kRGB_565, the low 16 bits of SK_ColorBLACK |
| // will be used. Conveniently, these are zeros, which is the |
| // representation for black in kRGB_565. |
| SkSwizzler::Fill(dstRow, dstInfo, dstRowBytes, dstHeight - y, |
| SK_ColorBLACK, nullptr, options.fZeroInitialized); |
| |
| // Prevent libjpeg from failing on incomplete decode |
| dinfo->output_scanline = dstHeight; |
| |
| // Finish the decode and indicate that the input was incomplete. |
| jpeg_finish_decompress(dinfo); |
| return fDecoderMgr->returnFailure("Incomplete image data", kIncompleteInput); |
| } |
| |
| // Convert to RGBA if necessary |
| if (JCS_CMYK == dinfo->out_color_space) { |
| convert_CMYK_to_RGBA(dstRow, dstInfo.width()); |
| } |
| |
| // Move to the next row |
| dstRow = SkTAddOffset<JSAMPLE>(dstRow, dstRowBytes); |
| } |
| jpeg_finish_decompress(dinfo); |
| |
| return kSuccess; |
| } |
| |
| /* |
| * Enable scanline decoding for jpegs |
| */ |
| class SkJpegScanlineDecoder : public SkScanlineDecoder { |
| public: |
| SkJpegScanlineDecoder(const SkImageInfo& srcInfo, SkJpegCodec* codec) |
| : INHERITED(srcInfo) |
| , fCodec(codec) |
| , fOpts() |
| {} |
| |
| /* |
| * Return a valid set of output dimensions for this decoder, given an input scale |
| */ |
| SkISize onGetScaledDimensions(float desiredScale) override { |
| return fCodec->onGetScaledDimensions(desiredScale); |
| } |
| |
| /* |
| * Create the swizzler based on the encoded format. |
| * The swizzler is only used for sampling in the x direction. |
| */ |
| |
| SkCodec::Result initializeSwizzler(const SkImageInfo& info, const SkCodec::Options& options) { |
| SkSwizzler::SrcConfig srcConfig; |
| switch (info.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: |
| //would have exited before now if the colorType was supported by jpeg |
| SkASSERT(false); |
| } |
| |
| fSwizzler.reset(SkSwizzler::CreateSwizzler(srcConfig, nullptr, info, options.fZeroInitialized, |
| this->getInfo())); |
| if (!fSwizzler) { |
| // FIXME: CreateSwizzler could fail for another reason. |
| return SkCodec::kUnimplemented; |
| } |
| return SkCodec::kSuccess; |
| } |
| |
| SkCodec::Result onStart(const SkImageInfo& dstInfo, const SkCodec::Options& options, |
| SkPMColor ctable[], int* ctableCount) override { |
| |
| // Rewind the stream if needed |
| if (!fCodec->rewindIfNeeded()) { |
| return SkCodec::kCouldNotRewind; |
| } |
| |
| // Set the jump location for libjpeg errors |
| if (setjmp(fCodec->fDecoderMgr->getJmpBuf())) { |
| SkCodecPrintf("setjmp: Error from libjpeg\n"); |
| return SkCodec::kInvalidInput; |
| } |
| |
| // Check if we can decode to the requested destination and set the output color space |
| if (!fCodec->setOutputColorSpace(dstInfo)) { |
| return SkCodec::kInvalidConversion; |
| } |
| |
| // Perform the necessary scaling |
| if (!fCodec->nativelyScaleToDimensions(dstInfo.width(), dstInfo.height())) { |
| // full native scaling to dstInfo dimensions not supported |
| |
| if (!SkScaledCodec::DimensionsSupportedForSampling(this->getInfo(), dstInfo)) { |
| return SkCodec::kInvalidScale; |
| } |
| // create swizzler for sampling |
| SkCodec::Result result = this->initializeSwizzler(dstInfo, options); |
| if (SkCodec::kSuccess != result) { |
| SkCodecPrintf("failed to initialize the swizzler.\n"); |
| return result; |
| } |
| fStorage.reset(get_row_bytes(fCodec->fDecoderMgr->dinfo())); |
| fSrcRow = static_cast<uint8_t*>(fStorage.get()); |
| } else { |
| fSrcRow = nullptr; |
| fSwizzler.reset(nullptr); |
| } |
| |
| // Now, given valid output dimensions, we can start the decompress |
| if (!jpeg_start_decompress(fCodec->fDecoderMgr->dinfo())) { |
| SkCodecPrintf("start decompress failed\n"); |
| return SkCodec::kInvalidInput; |
| } |
| |
| fOpts = options; |
| |
| return SkCodec::kSuccess; |
| } |
| |
| virtual ~SkJpegScanlineDecoder() { |
| if (setjmp(fCodec->fDecoderMgr->getJmpBuf())) { |
| SkCodecPrintf("setjmp: Error in libjpeg finish_decompress\n"); |
| return; |
| } |
| |
| // We may not have decoded the entire image. Prevent libjpeg-turbo from failing on a |
| // partial decode. |
| fCodec->fDecoderMgr->dinfo()->output_scanline = fCodec->getInfo().height(); |
| jpeg_finish_decompress(fCodec->fDecoderMgr->dinfo()); |
| } |
| |
| SkCodec::Result onGetScanlines(void* dst, int count, size_t rowBytes) override { |
| // Set the jump location for libjpeg errors |
| if (setjmp(fCodec->fDecoderMgr->getJmpBuf())) { |
| return fCodec->fDecoderMgr->returnFailure("setjmp", SkCodec::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(fCodec->fDecoderMgr->dinfo(), &dstRow, 1); |
| if (rowsDecoded != 1) { |
| SkSwizzler::Fill(dstRow, this->dstInfo(), rowBytes, count - y, |
| SK_ColorBLACK, nullptr, fOpts.fZeroInitialized); |
| fCodec->fDecoderMgr->dinfo()->output_scanline = this->dstInfo().height(); |
| return SkCodec::kIncompleteInput; |
| } |
| |
| // Convert to RGBA if necessary |
| if (JCS_CMYK == fCodec->fDecoderMgr->dinfo()->out_color_space) { |
| convert_CMYK_to_RGBA(dstRow, fCodec->fDecoderMgr->dinfo()->output_width); |
| } |
| |
| if(fSwizzler) { |
| // use swizzler to sample row |
| fSwizzler->swizzle(dst, dstRow); |
| dst = SkTAddOffset<JSAMPLE>(dst, rowBytes); |
| } else { |
| dstRow = SkTAddOffset<JSAMPLE>(dstRow, rowBytes); |
| } |
| } |
| return SkCodec::kSuccess; |
| } |
| |
| #ifndef TURBO_HAS_SKIP |
| // TODO (msarett): Make this a member function and avoid reallocating the |
| // memory buffer on each call to skip. |
| #define jpeg_skip_scanlines(dinfo, count) \ |
| SkAutoMalloc storage(get_row_bytes(dinfo)); \ |
| uint8_t* storagePtr = static_cast<uint8_t*>(storage.get()); \ |
| for (int y = 0; y < count; y++) { \ |
| jpeg_read_scanlines(dinfo, &storagePtr, 1); \ |
| } |
| #endif |
| |
| SkCodec::Result onSkipScanlines(int count) override { |
| // Set the jump location for libjpeg errors |
| if (setjmp(fCodec->fDecoderMgr->getJmpBuf())) { |
| return fCodec->fDecoderMgr->returnFailure("setjmp", SkCodec::kInvalidInput); |
| } |
| |
| jpeg_skip_scanlines(fCodec->fDecoderMgr->dinfo(), count); |
| |
| return SkCodec::kSuccess; |
| } |
| |
| SkEncodedFormat onGetEncodedFormat() const override { |
| return kJPEG_SkEncodedFormat; |
| } |
| |
| private: |
| SkAutoTDelete<SkJpegCodec> fCodec; |
| SkAutoMalloc fStorage; // Only used if sampling is needed |
| uint8_t* fSrcRow; // Only used if sampling is needed |
| SkCodec::Options fOpts; |
| SkAutoTDelete<SkSwizzler> fSwizzler; |
| |
| typedef SkScanlineDecoder INHERITED; |
| }; |
| |
| SkScanlineDecoder* SkJpegCodec::NewSDFromStream(SkStream* stream) { |
| SkAutoTDelete<SkJpegCodec> codec(static_cast<SkJpegCodec*>(SkJpegCodec::NewFromStream(stream))); |
| if (!codec) { |
| return nullptr; |
| } |
| |
| const SkImageInfo& srcInfo = codec->getInfo(); |
| |
| // Return the new scanline decoder |
| return new SkJpegScanlineDecoder(srcInfo, codec.detach()); |
| } |
