/*
* 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 "src/codec/SkJpegCodec.h"
#include "include/codec/SkCodec.h"
#include "include/codec/SkJpegDecoder.h"
#include "include/core/SkAlphaType.h"
#include "include/core/SkColorType.h"
#include "include/core/SkData.h"
#include "include/core/SkImageInfo.h"
#include "include/core/SkPixmap.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkStream.h"
#include "include/core/SkTypes.h"
#include "include/core/SkYUVAInfo.h"
#include "include/private/base/SkAlign.h"
#include "include/private/base/SkMalloc.h"
#include "include/private/base/SkTemplates.h"
#include "modules/skcms/skcms.h"
#include "src/codec/SkCodecPriv.h"
#include "src/codec/SkJpegConstants.h"
#include "src/codec/SkJpegDecoderMgr.h"
#include "src/codec/SkJpegMetadataDecoderImpl.h"
#include "src/codec/SkJpegPriv.h"
#include "src/codec/SkParseEncodedOrigin.h"
#include "src/codec/SkSwizzler.h"
#ifdef SK_CODEC_DECODES_JPEG_GAINMAPS
#include "include/private/SkGainmapInfo.h"
#endif // SK_CODEC_DECODES_JPEG_GAINMAPS
#include <array>
#include <csetjmp>
#include <cstring>
#include <utility>
using namespace skia_private;
class SkSampler;
struct SkGainmapInfo;
// This warning triggers false postives way too often in here.
#if defined(__GNUC__) && !
defined(__clang__)
#pragma GCC diagnostic ignored
"-Wclobbered"
#endif
extern "C" {
#include "jpeglib.h" // NO_G3_REWRITE
}
bool SkJpegCodec::IsJpeg(
const void* buffer, size_t bytesRead) {
return bytesRead >=
sizeof(kJpegSig) && !memcmp(buffer, kJpegSig,
sizeof(kJpegSig));
}
SkJpegMarkerList get_sk_marker_list(jpeg_decompress_struct* dinfo) {
SkJpegMarkerList markerList;
for (
auto* marker = dinfo->marker_list; marker; marker = marker->next) {
markerList.emplace_back(marker->marker,
SkData::MakeWithoutCopy(marker->data, marker->data_length));
}
return markerList;
}
static SkEncodedOrigin get_exif_orientation(sk_sp<SkData> exifData) {
SkEncodedOrigin origin = kDefault_SkEncodedOrigin;
if (exifData && SkParseEncodedOrigin(exifData->bytes(), exifData->size(), &origin)) {
return origin;
}
return kDefault_SkEncodedOrigin;
}
SkCodec::Result SkJpegCodec::ReadHeader(
SkStream* stream,
SkCodec** codecOut,
JpegDecoderMgr** decoderMgrOut,
std::unique_ptr<SkEncodedInfo::ICCProfile> defaultColorProfile) {
// Create a JpegDecoderMgr to own all of the decompress information
std::unique_ptr<JpegDecoderMgr> decoderMgr(
new JpegDecoderMgr(stream));
// libjpeg errors will be caught and reported here
skjpeg_error_mgr::AutoPushJmpBuf jmp(decoderMgr->errorMgr());
if (setjmp(jmp)) {
return decoderMgr->returnFailure(
"ReadHeader", kInvalidInput);
}
// Initialize the decompress info and the source manager
decoderMgr->init();
auto* dinfo = decoderMgr->dinfo();
// Instruct jpeg library to save the markers that we care about. Since
// the orientation and color profile will not change, we can skip this
// step on rewinds.
if (codecOut) {
jpeg_save_markers(dinfo, kExifMarker, 0xFFFF);
jpeg_save_markers(dinfo, kICCMarker, 0xFFFF);
jpeg_save_markers(dinfo, kMpfMarker, 0xFFFF);
}
// Read the jpeg header
switch (jpeg_read_header(dinfo,
TRUE)) {
case JPEG_HEADER_OK:
break;
case JPEG_SUSPENDED:
return decoderMgr->returnFailure(
"ReadHeader", kIncompleteInput);
default:
return decoderMgr->returnFailure(
"ReadHeader", kInvalidInput);
}
if (codecOut) {
// Get the encoded color type
SkEncodedInfo::Color color;
if (!decoderMgr->getEncodedColor(&color)) {
return kInvalidInput;
}
auto metadataDecoder =
std::make_unique<SkJpegMetadataDecoderImpl>(get_sk_marker_list(dinfo));
SkEncodedOrigin orientation =
get_exif_orientation(metadataDecoder->getExifMetadata(
/*copyData=*/false));
std::unique_ptr<SkEncodedInfo::ICCProfile> profile;
if (
auto iccProfileData = metadataDecoder->getICCProfileData(
/*copyData=*/true)) {
profile = SkEncodedInfo::ICCProfile::Make(std::move(iccProfileData));
}
if (profile) {
auto type = profile->profile()->data_color_space;
switch (decoderMgr->dinfo()->jpeg_color_space) {
case JCS_CMYK:
case JCS_YCCK:
if (type != skcms_Signature_CMYK) {
profile = nullptr;
}
break;
case JCS_GRAYSCALE:
if (type != skcms_Signature_Gray &&
type != skcms_Signature_RGB)
{
profile = nullptr;
}
break;
default:
if (type != skcms_Signature_RGB) {
profile = nullptr;
}
break;
}
}
if (!profile) {
profile = std::move(defaultColorProfile);
}
SkEncodedInfo info = SkEncodedInfo::Make(dinfo->image_width, dinfo->image_height,
color, SkEncodedInfo::kOpaque_Alpha, 8,
std::move(profile));
SkJpegCodec* codec =
new SkJpegCodec(std::move(info),
std::unique_ptr<SkStream>(stream),
decoderMgr.release(),
orientation);
*codecOut = codec;
}
else {
SkASSERT(nullptr != decoderMgrOut);
*decoderMgrOut = decoderMgr.release();
}
return kSuccess;
}
std::unique_ptr<SkCodec> SkJpegCodec::MakeFromStream(std::unique_ptr<SkStream> stream,
Result* result) {
return SkJpegCodec::MakeFromStream(std::move(stream), result, nullptr);
}
std::unique_ptr<SkCodec> SkJpegCodec::MakeFromStream(std::unique_ptr<SkStream> stream,
Result* result, std::unique_ptr<SkEncodedInfo::ICCProfile> defaultColorProfile) {
SkASSERT(result);
if (!stream) {
*result = SkCodec::kInvalidInput;
return nullptr;
}
SkCodec* codec = nullptr;
*result = ReadHeader(stream.get(), &codec, nullptr, std::move(defaultColorProfile));
if (kSuccess == *result) {
// Codec has taken ownership of the stream, we do not need to delete it
SkASSERT(codec);
stream.release();
return std::unique_ptr<SkCodec>(codec);
}
return nullptr;
}
SkJpegCodec::SkJpegCodec(SkEncodedInfo&& info,
std::unique_ptr<SkStream> stream,
JpegDecoderMgr* decoderMgr,
SkEncodedOrigin origin)
: INHERITED(std::move(info), skcms_PixelFormat_RGBA_8888, std::move(stream), origin)
, fDecoderMgr(decoderMgr)
, fReadyState(decoderMgr->dinfo()->global_state) {}
SkJpegCodec::~SkJpegCodec() =
default;
/*
* Return the row bytes of a particular image type and width
*/
static size_t get_row_bytes(
const j_decompress_ptr dinfo) {
const size_t 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->dimensions().width();
dinfo.image_height = this->dimensions().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 (kSuccess != ReadHeader(this->stream(), nullptr, &decoderMgr, nullptr)) {
return fDecoderMgr->returnFalse(
"onRewind");
}
SkASSERT(nullptr != decoderMgr);
fDecoderMgr.reset(decoderMgr);
fSwizzler.reset(nullptr);
fSwizzleSrcRow = nullptr;
fColorXformSrcRow = nullptr;
fStorage.reset();
return true;
}
bool SkJpegCodec::conversionSupported(
const SkImageInfo& dstInfo,
bool srcIsOpaqu
e,
bool needsColorXform) {
SkASSERT(srcIsOpaque);
if (kUnknown_SkAlphaType == dstInfo.alphaType()) {
return false;
}
if (kOpaque_SkAlphaType != dstInfo.alphaType()) {
SkCodecPrintf("Warning: an opaque image should be decoded as opaque "
"- it is being decoded as non-opaque, which will draw slower\n");
}
J_COLOR_SPACE encodedColorType = fDecoderMgr->dinfo()->jpeg_color_space;
// Check for valid color types and set the output color space
switch (dstInfo.colorType()) {
case kRGBA_8888_SkColorType:
fDecoderMgr->dinfo()->out_color_space = JCS_EXT_RGBA;
break;
case kBGRA_8888_SkColorType:
if (needsColorXform) {
// Always using RGBA as the input format for color xforms makes the
// implementation a little simpler.
fDecoderMgr->dinfo()->out_color_space = JCS_EXT_RGBA;
} else {
fDecoderMgr->dinfo()->out_color_space = JCS_EXT_BGRA;
}
break;
case kRGB_565_SkColorType:
if (needsColorXform) {
fDecoderMgr->dinfo()->out_color_space = JCS_EXT_RGBA;
} else {
fDecoderMgr->dinfo()->dither_mode = JDITHER_NONE;
fDecoderMgr->dinfo()->out_color_space = JCS_RGB565;
}
break;
case kGray_8_SkColorType:
if (JCS_GRAYSCALE != encodedColorType) {
return false;
}
if (needsColorXform) {
fDecoderMgr->dinfo()->out_color_space = JCS_EXT_RGBA;
} else {
fDecoderMgr->dinfo()->out_color_space = JCS_GRAYSCALE;
}
break;
case kBGRA_10101010_XR_SkColorType:
case kBGR_101010x_XR_SkColorType:
case kRGBA_F16_SkColorType:
SkASSERT(needsColorXform);
fDecoderMgr->dinfo()->out_color_space = JCS_EXT_RGBA;
break;
default:
return false;
}
// Check if we will decode to CMYK. libjpeg-turbo does not convert CMYK to RGBA, so
// we must do it ourselves.
if (JCS_CMYK == encodedColorType || JCS_YCCK == encodedColorType) {
fDecoderMgr->dinfo()->out_color_space = JCS_CMYK;
}
return true;
}
/*
* Checks if we can natively scale to the requested dimensions and natively scales the
* dimensions if possible
*/
bool SkJpegCodec::onDimensionsSupported(const SkISize& size) {
skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
if (setjmp(jmp)) {
return fDecoderMgr->returnFalse("onDimensionsSupported");
}
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->dimensions().width();
dinfo.image_height = this->dimensions().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;
}
int SkJpegCodec::readRows(const SkImageInfo& dstInfo, void* dst, size_t rowBytes, int count,
const Options& opts) {
// Set the jump location for libjpeg-turbo errors
skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
if (setjmp(jmp)) {
return 0;
}
// When fSwizzleSrcRow is non-null, it means that we need to swizzle. In this case,
// we will always decode into fSwizzlerSrcRow before swizzling into the next buffer.
// We can never swizzle "in place" because the swizzler may perform sampling and/or
// subsetting.
// When fColorXformSrcRow is non-null, it means that we need to color xform and that
// we cannot color xform "in place" (many times we can, but not when the src and dst
// are different sizes).
// In this case, we will color xform from fColorXformSrcRow into the dst.
JSAMPLE* decodeDst = (JSAMPLE*) dst;
uint32_t* swizzleDst = (uint32_t*) dst;
size_t decodeDstRowBytes = rowBytes;
size_t swizzleDstRowBytes = rowBytes;
int dstWidth = opts.fSubset ? opts.fSubset->width() : dstInfo.width();
if (fSwizzleSrcRow && fColorXformSrcRow) {
decodeDst = (JSAMPLE*) fSwizzleSrcRow;
swizzleDst = fColorXformSrcRow;
decodeDstRowBytes = 0;
swizzleDstRowBytes = 0;
dstWidth = fSwizzler->swizzleWidth();
} else if (fColorXformSrcRow) {
decodeDst = (JSAMPLE*) fColorXformSrcRow;
swizzleDst = fColorXformSrcRow;
decodeDstRowBytes = 0;
swizzleDstRowBytes = 0;
} else if (fSwizzleSrcRow) {
decodeDst = (JSAMPLE*) fSwizzleSrcRow;
decodeDstRowBytes = 0;
dstWidth = fSwizzler->swizzleWidth();
}
for (int y = 0; y < count; y++) {
uint32_t lines = jpeg_read_scanlines(fDecoderMgr->dinfo(), &decodeDst, 1);
if (0 == lines) {
return y;
}
if (fSwizzler) {
fSwizzler->swizzle(swizzleDst, decodeDst);
}
if (this->colorXform()) {
this->applyColorXform(dst, swizzleDst, dstWidth);
dst = SkTAddOffset<void>(dst, rowBytes);
}
decodeDst = SkTAddOffset<JSAMPLE>(decodeDst, decodeDstRowBytes);
swizzleDst = SkTAddOffset<uint32_t>(swizzleDst, swizzleDstRowBytes);
}
return count;
}
/*
* This is a bit tricky. We only need the swizzler to do format conversion if the jpeg is
* encoded as CMYK.
* And even then we still may not need it. If the jpeg has a CMYK color profile and a color
* xform, the color xform will handle the CMYK->RGB conversion.
*/
static inline bool needs_swizzler_to_convert_from_cmyk(J_COLOR_SPACE jpegColorType,
const skcms_ICCProfile* srcProfile,
bool hasColorSpaceXform) {
if (JCS_CMYK != jpegColorType) {
return false;
}
bool hasCMYKColorSpace = srcProfile && srcProfile->data_color_space == skcms_Signature_CMYK;
return !hasCMYKColorSpace || !hasColorSpaceXform;
}
/*
* Performs the jpeg decode
*/
SkCodec::Result SkJpegCodec::onGetPixels(const SkImageInfo& dstInfo,
void* dst, size_t dstRowBytes,
const Options& options,
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
skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
if (setjmp(jmp)) {
return fDecoderMgr->returnFailure("setjmp", kInvalidInput);
}
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 (needs_swizzler_to_convert_from_cmyk(dinfo->out_color_space,
this->getEncodedInfo().profile(), this->colorXform())) {
this->initializeSwizzler(dstInfo, options, true);
}
if (!this->allocateStorage(dstInfo)) {
return kInternalError;
}
int rows = this->readRows(dstInfo, dst, dstRowBytes, dstInfo.height(), options);
if (rows < dstInfo.height()) {
*rowsDecoded = rows;
return fDecoderMgr->returnFailure("Incomplete image data", kIncompleteInput);
}
return kSuccess;
}
bool SkJpegCodec::allocateStorage(const SkImageInfo& dstInfo) {
int dstWidth = dstInfo.width();
size_t swizzleBytes = 0;
if (fSwizzler) {
swizzleBytes = get_row_bytes(fDecoderMgr->dinfo());
dstWidth = fSwizzler->swizzleWidth();
SkASSERT(!this->colorXform() || SkIsAlign4(swizzleBytes));
}
size_t xformBytes = 0;
if (this->colorXform() && sizeof(uint32_t) != dstInfo.bytesPerPixel()) {
xformBytes = dstWidth * sizeof(uint32_t);
}
size_t totalBytes = swizzleBytes + xformBytes;
if (totalBytes > 0) {
if (!fStorage.reset(totalBytes)) {
return false;
}
fSwizzleSrcRow = (swizzleBytes > 0) ? fStorage.get() : nullptr;
fColorXformSrcRow = (xformBytes > 0) ?
SkTAddOffset<uint32_t>(fStorage.get(), swizzleBytes) : nullptr;
}
return true;
}
void SkJpegCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Options& options,
bool needsCMYKToRGB) {
Options swizzlerOptions = options;
if (options.fSubset) {
// Use fSwizzlerSubset if this is a subset decode. This is necessary in the case
// where libjpeg-turbo provides a subset and then we need to subset it further.
// Also, verify that fSwizzlerSubset is initialized and valid.
SkASSERT(!fSwizzlerSubset.isEmpty() && fSwizzlerSubset.x() <= options.fSubset->x() &&
fSwizzlerSubset.width() == options.fSubset->width());
swizzlerOptions.fSubset = &fSwizzlerSubset;
}
SkImageInfo swizzlerDstInfo = dstInfo;
if (this->colorXform()) {
// The color xform will be expecting RGBA 8888 input.
swizzlerDstInfo = swizzlerDstInfo.makeColorType(kRGBA_8888_SkColorType);
}
if (needsCMYKToRGB) {
// The swizzler is used to convert to from CMYK.
// The swizzler does not use the width or height on SkEncodedInfo.
auto swizzlerInfo = SkEncodedInfo::Make(0, 0, SkEncodedInfo::kInvertedCMYK_Color,
SkEncodedInfo::kOpaque_Alpha, 8);
fSwizzler = SkSwizzler::Make(swizzlerInfo, nullptr, swizzlerDstInfo, swizzlerOptions);
} else {
int srcBPP = 0;
switch (fDecoderMgr->dinfo()->out_color_space) {
case JCS_EXT_RGBA:
case JCS_EXT_BGRA:
case JCS_CMYK:
srcBPP = 4;
break;
case JCS_RGB565:
srcBPP = 2;
break;
case JCS_GRAYSCALE:
srcBPP = 1;
break;
default:
SkASSERT(false);
break;
}
fSwizzler = SkSwizzler::MakeSimple(srcBPP, swizzlerDstInfo, swizzlerOptions);
}
SkASSERT(fSwizzler);
}
SkSampler* SkJpegCodec::getSampler(bool createIfNecessary) {
if (!createIfNecessary || fSwizzler) {
SkASSERT(!fSwizzler || (fSwizzleSrcRow && fStorage.get() == fSwizzleSrcRow));
return fSwizzler.get();
}
bool needsCMYKToRGB = needs_swizzler_to_convert_from_cmyk(
fDecoderMgr->dinfo()->out_color_space, this->getEncodedInfo().profile(),
this->colorXform());
this->initializeSwizzler(this->dstInfo(), this->options(), needsCMYKToRGB);
if (!this->allocateStorage(this->dstInfo())) {
return nullptr;
}
return fSwizzler.get();
}
SkCodec::Result SkJpegCodec::onStartScanlineDecode(const SkImageInfo& dstInfo,
const Options& options) {
// Set the jump location for libjpeg errors
skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
if (setjmp(jmp)) {
SkCodecPrintf("setjmp: Error from libjpeg\n");
return kInvalidInput;
}
if (!jpeg_start_decompress(fDecoderMgr->dinfo())) {
SkCodecPrintf("start decompress failed\n");
return kInvalidInput;
}
bool needsCMYKToRGB = needs_swizzler_to_convert_from_cmyk(
fDecoderMgr->dinfo()->out_color_space, this->getEncodedInfo().profile(),
this->colorXform());
if (options.fSubset) {
uint32_t startX = options.fSubset->x();
uint32_t width = options.fSubset->width();
// libjpeg-turbo may need to align startX to a multiple of the IDCT
// block size. If this is the case, it will decrease the value of
// startX to the appropriate alignment and also increase the value
// of width so that the right edge of the requested subset remains
// the same.
jpeg_crop_scanline(fDecoderMgr->dinfo(), &startX, &width);
SkASSERT(startX <= (uint32_t) options.fSubset->x());
SkASSERT(width >= (uint32_t) options.fSubset->width());
SkASSERT(startX + width >= (uint32_t) options.fSubset->right());
// Instruct the swizzler (if it is necessary) to further subset the
// output provided by libjpeg-turbo.
//
// We set this here (rather than in the if statement below), so that
// if (1) we don't need a swizzler for the subset, and (2) we need a
// swizzler for CMYK, the swizzler will still use the proper subset
// dimensions.
//
// Note that the swizzler will ignore the y and height parameters of
// the subset. Since the scanline decoder (and the swizzler) handle
// one row at a time, only the subsetting in the x-dimension matters.
fSwizzlerSubset.setXYWH(options.fSubset->x() - startX, 0,
options.fSubset->width(), options.fSubset->height());
// We will need a swizzler if libjpeg-turbo cannot provide the exact
// subset that we request.
if (startX != (uint32_t) options.fSubset->x() ||
width != (uint32_t) options.fSubset->width()) {
this->initializeSwizzler(dstInfo, options, needsCMYKToRGB);
}
}
// Make sure we have a swizzler if we are converting from CMYK.
if (!fSwizzler && needsCMYKToRGB) {
this->initializeSwizzler(dstInfo, options, true);
}
if (!this->allocateStorage(dstInfo)) {
return kInternalError;
}
return kSuccess;
}
int SkJpegCodec::onGetScanlines(void* dst, int count, size_t dstRowBytes) {
int rows = this->readRows(this->dstInfo(), dst, dstRowBytes, count, this->options());
if (rows < count) {
// This allows us to skip calling jpeg_finish_decompress().
fDecoderMgr->dinfo()->output_scanline = this->dstInfo().height();
}
return rows;
}
bool SkJpegCodec::onSkipScanlines(int count) {
// Set the jump location for libjpeg errors
skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
if (setjmp(jmp)) {
return fDecoderMgr->returnFalse("onSkipScanlines");
}
return (uint32_t) count == jpeg_skip_scanlines(fDecoderMgr->dinfo(), count);
}
static bool is_yuv_supported(const jpeg_decompress_struct* dinfo,
const SkJpegCodec& codec,
const SkYUVAPixmapInfo::SupportedDataTypes* supportedDataTypes,
SkYUVAPixmapInfo* yuvaPixmapInfo) {
// Scaling is not supported in raw data mode.
SkASSERT(dinfo->scale_num == dinfo->scale_denom);
// I can't imagine that this would ever change, but we do depend on it.
static_assert(8 == DCTSIZE, "DCTSIZE (defined in jpeg library) should always be 8.");
if (JCS_YCbCr != dinfo->jpeg_color_space) {
return false;
}
SkASSERT(3 == dinfo->num_components);
SkASSERT(dinfo->comp_info);
// It is possible to perform a YUV decode for any combination of
// horizontal and vertical sampling that is supported by
// libjpeg/libjpeg-turbo. However, we will start by supporting only the
// common cases (where U and V have samp_factors of one).
//
// The definition of samp_factor is kind of the opposite of what SkCodec
// thinks of as a sampling factor. samp_factor is essentially a
// multiplier, and the larger the samp_factor is, the more samples that
// there will be. Ex:
// U_plane_width = image_width * (U_h_samp_factor / max_h_samp_factor)
//
// Supporting cases where the samp_factors for U or V were larger than
// that of Y would be an extremely difficult change, given that clients
// allocate memory as if the size of the Y plane is always the size of the
// image. However, this case is very, very rare.
if ((1 != dinfo->comp_info[1].h_samp_factor) ||
(1 != dinfo->comp_info[1].v_samp_factor) ||
(1 != dinfo->comp_info[2].h_samp_factor) ||
(1 != dinfo->comp_info[2].v_samp_factor))
{
return false;
}
// Support all common cases of Y samp_factors.
// TODO (msarett): As mentioned above, it would be possible to support
// more combinations of samp_factors. The issues are:
// (1) Are there actually any images that are not covered
// by these cases?
// (2) How much complexity would be added to the
// implementation in order to support these rare
// cases?
int hSampY = dinfo->comp_info[0].h_samp_factor;
int vSampY = dinfo->comp_info[0].v_samp_factor;
SkASSERT(hSampY == dinfo->max_h_samp_factor);
SkASSERT(vSampY == dinfo->max_v_samp_factor);
SkYUVAInfo::Subsampling tempSubsampling;
if (1 == hSampY && 1 == vSampY) {
tempSubsampling = SkYUVAInfo::Subsampling::k444;
} else if (2 == hSampY && 1 == vSampY) {
tempSubsampling = SkYUVAInfo::Subsampling::k422;
} else if (2 == hSampY && 2 == vSampY) {
tempSubsampling = SkYUVAInfo::Subsampling::k420;
} else if (1 == hSampY && 2 == vSampY) {
tempSubsampling = SkYUVAInfo::Subsampling::k440;
} else if (4 == hSampY && 1 == vSampY) {
tempSubsampling = SkYUVAInfo::Subsampling::k411;
} else if (4 == hSampY && 2 == vSampY) {
tempSubsampling = SkYUVAInfo::Subsampling::k410;
} else {
return false;
}
if (supportedDataTypes &&
!supportedDataTypes->supported(SkYUVAInfo::PlaneConfig::kY_U_V,
SkYUVAPixmapInfo::DataType::kUnorm8)) {
return false;
}
if (yuvaPixmapInfo) {
SkColorType colorTypes[SkYUVAPixmapInfo::kMaxPlanes];
size_t rowBytes[SkYUVAPixmapInfo::kMaxPlanes];
for (int i = 0; i < 3; ++i) {
colorTypes[i] = kAlpha_8_SkColorType;
rowBytes[i] = dinfo->comp_info[i].width_in_blocks * DCTSIZE;
}
SkYUVAInfo yuvaInfo(codec.dimensions(),
SkYUVAInfo::PlaneConfig::kY_U_V,
tempSubsampling,
kJPEG_Full_SkYUVColorSpace,
codec.getOrigin(),
SkYUVAInfo::Siting::kCentered,
SkYUVAInfo::Siting::kCentered);
*yuvaPixmapInfo = SkYUVAPixmapInfo(yuvaInfo, colorTypes, rowBytes);
}
return true;
}
bool SkJpegCodec::onQueryYUVAInfo(const SkYUVAPixmapInfo::SupportedDataTypes& supportedDataTypes,
SkYUVAPixmapInfo* yuvaPixmapInfo) const {
jpeg_decompress_struct* dinfo = fDecoderMgr->dinfo();
return is_yuv_supported(dinfo, *this, &supportedDataTypes, yuvaPixmapInfo);
}
SkCodec::Result SkJpegCodec::onGetYUVAPlanes(const SkYUVAPixmaps& yuvaPixmaps) {
// Get a pointer to the decompress info since we will use it quite frequently
jpeg_decompress_struct* dinfo = fDecoderMgr->dinfo();
if (!is_yuv_supported(dinfo, *this, nullptr, nullptr)) {
return fDecoderMgr->returnFailure("onGetYUVAPlanes", kInvalidInput);
}
// Set the jump location for libjpeg errors
skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
if (setjmp(jmp)) {
return fDecoderMgr->returnFailure("setjmp", kInvalidInput);
}
dinfo->raw_data_out = TRUE;
if (!jpeg_start_decompress(dinfo)) {
return fDecoderMgr->returnFailure("startDecompress", kInvalidInput);
}
const std::array<SkPixmap, SkYUVAPixmaps::kMaxPlanes>& planes = yuvaPixmaps.planes();
#ifdef SK_DEBUG
{
// A previous implementation claims that the return value of is_yuv_supported()
// may change after calling jpeg_start_decompress(). It looks to me like this
// was caused by a bug in the old code, but we'll be safe and check here.
// Also check that pixmap properties agree with expectations.
SkYUVAPixmapInfo info;
SkASSERT(is_yuv_supported(dinfo, *this, nullptr, &info));
SkASSERT(info.yuvaInfo() == yuvaPixmaps.yuvaInfo());
for (int i = 0; i < info.numPlanes(); ++i) {
SkASSERT(planes[i].colorType() == kAlpha_8_SkColorType);
SkASSERT(info.planeInfo(i) == planes[i].info());
}
}
#endif
// Build a JSAMPIMAGE to handle output from libjpeg-turbo. A JSAMPIMAGE has
// a 2-D array of pixels for each of the components (Y, U, V) in the image.
// Cheat Sheet:
// JSAMPIMAGE == JSAMPLEARRAY* == JSAMPROW** == JSAMPLE***
JSAMPARRAY yuv[3];
// Set aside enough space for pointers to rows of Y, U, and V.
JSAMPROW rowptrs[2 * DCTSIZE + DCTSIZE + DCTSIZE];
yuv[0] = &rowptrs[0]; // Y rows (DCTSIZE or 2 * DCTSIZE)
yuv[1] = &rowptrs[2 * DCTSIZE]; // U rows (DCTSIZE)
yuv[2] = &rowptrs[3 * DCTSIZE]; // V rows (DCTSIZE)
// Initialize rowptrs.
int numYRowsPerBlock = DCTSIZE * dinfo->comp_info[0].v_samp_factor;
static_assert(sizeof(JSAMPLE) == 1);
for (int i = 0; i < numYRowsPerBlock; i++) {
rowptrs[i] = static_cast<JSAMPLE*>(planes[0].writable_addr()) + i* planes[0].rowBytes();
}
for (int i = 0; i < DCTSIZE; i++) {
rowptrs[i + 2 * DCTSIZE] =
static_cast<JSAMPLE*>(planes[1].writable_addr()) + i* planes[1].rowBytes();
rowptrs[i + 3 * DCTSIZE] =
static_cast<JSAMPLE*>(planes[2].writable_addr()) + i* planes[2].rowBytes();
}
// After each loop iteration, we will increment pointers to Y, U, and V.
size_t blockIncrementY = numYRowsPerBlock * planes[0].rowBytes();
size_t blockIncrementU = DCTSIZE * planes[1].rowBytes();
size_t blockIncrementV = DCTSIZE * planes[2].rowBytes();
uint32_t numRowsPerBlock = numYRowsPerBlock;
// We intentionally round down here, as this first loop will only handle
// full block rows. As a special case at the end, we will handle any
// remaining rows that do not make up a full block.
const int numIters = dinfo->output_height / numRowsPerBlock;
for (int i = 0; i < numIters; i++) {
JDIMENSION linesRead = jpeg_read_raw_data(dinfo, yuv, numRowsPerBlock);
if (linesRead < numRowsPerBlock) {
// FIXME: Handle incomplete YUV decodes without signalling an error.
return kInvalidInput;
}
// Update rowptrs.
for (int j = 0; j < numYRowsPerBlock; j++) {
rowptrs[j] += blockIncrementY;
}
for (int j = 0; j < DCTSIZE; j++) {
rowptrs[j + 2 * DCTSIZE] += blockIncrementU;
rowptrs[j + 3 * DCTSIZE] += blockIncrementV;
}
}
uint32_t remainingRows = dinfo->output_height - dinfo->output_scanline;
SkASSERT(remainingRows == dinfo->output_height % numRowsPerBlock);
SkASSERT(dinfo->output_scanline == numIters * numRowsPerBlock);
if (remainingRows > 0) {
// libjpeg-turbo needs memory to be padded by the block sizes. We will fulfill
// this requirement using an extra row buffer.
// FIXME: Should SkCodec have an extra memory buffer that can be shared among
// all of the implementations that use temporary/garbage memory?
AutoTMalloc<JSAMPLE> extraRow(planes[0].rowBytes());
for (int i = remainingRows; i < numYRowsPerBlock; i++) {
rowptrs[i] = extraRow.get();
}
int remainingUVRows = dinfo->comp_info[1].downsampled_height - DCTSIZE * numIters;
for (int i = remainingUVRows; i < DCTSIZE; i++) {
rowptrs[i + 2 * DCTSIZE] = extraRow.get();
rowptrs[i + 3 * DCTSIZE] = extraRow.get();
}
JDIMENSION linesRead = jpeg_read_raw_data(dinfo, yuv, numRowsPerBlock);
if (linesRead < remainingRows) {
// FIXME: Handle incomplete YUV decodes without signalling an error.
return kInvalidInput;
}
}
return kSuccess;
}
bool SkJpegCodec::onGetGainmapCodec(SkGainmapInfo* info, std::unique_ptr<SkCodec>* gainmapCodec) {
std::unique_ptr<SkStream> stream;
if (!this->onGetGainmapInfo(info, &stream)) {
return false;
}
if (gainmapCodec) {
Result result;
*gainmapCodec = MakeFromStream(std::move(stream), &result);
if (!*gainmapCodec) {
return false;
}
}
return true;
}
bool SkJpegCodec::onGetGainmapInfo(SkGainmapInfo* info,
std::unique_ptr<SkStream>* gainmapImageStream) {
#ifdef SK_CODEC_DECODES_JPEG_GAINMAPS
sk_sp<SkData> gainmap_data;
SkGainmapInfo gainmap_info;
auto metadataDecoder =
std::make_unique<SkJpegMetadataDecoderImpl>(get_sk_marker_list(fDecoderMgr->dinfo()));
if (!metadataDecoder->findGainmapImage(
fDecoderMgr->getSourceMgr(), gainmap_data, gainmap_info)) {
return false;
}
*info = gainmap_info;
*gainmapImageStream = SkMemoryStream::Make(gainmap_data);
return true;
#else
return false;
#endif // SK_CODEC_DECODES_JPEG_GAINMAPS
}
namespace SkJpegDecoder {
bool IsJpeg(const void* data, size_t len) {
return SkJpegCodec::IsJpeg(data, len);
}
std::unique_ptr<SkCodec> Decode(std::unique_ptr<SkStream> stream,
SkCodec::Result* outResult,
SkCodecs::DecodeContext) {
SkCodec::Result resultStorage;
if (!outResult) {
outResult = &resultStorage;
}
return SkJpegCodec::MakeFromStream(std::move(stream), outResult);
}
std::unique_ptr<SkCodec> Decode(sk_sp<SkData> data,
SkCodec::Result* outResult,
SkCodecs::DecodeContext) {
if (!data) {
if (outResult) {
*outResult = SkCodec::kInvalidInput;
}
return nullptr;
}
return Decode(SkMemoryStream::Make(std::move(data)), outResult, nullptr);
}
} // namespace SkJpegDecoder
