blob: 83656da42dc8d110f106ffc3693b621ccdad388c [file] [log] [blame]
/*
* 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 "SkScanlineDecoder.h"
#include "SkStream.h"
#include "SkTemplates.h"
#include "SkTypes.h"
// stdio is needed for libjpeg-turbo
#include <stdio.h>
extern "C" {
#include "jpeglibmangler.h"
#include "jerror.h"
#include "jpegint.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(SkNEW_ARGS(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 != chromium_jpeg_read_header(decoderMgr->dinfo(), true)) {
return decoderMgr->returnFalse("read_header");
}
if (NULL != 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 = SkNEW_ARGS(SkJpegCodec, (imageInfo, stream, decoderMgr.detach()));
} else {
SkASSERT(NULL != decoderMgrOut);
*decoderMgrOut = decoderMgr.detach();
}
return true;
}
SkCodec* SkJpegCodec::NewFromStream(SkStream* stream) {
SkAutoTDelete<SkStream> streamDeleter(stream);
SkCodec* codec = NULL;
if (ReadHeader(stream, &codec, NULL)) {
// Codec has taken ownership of the stream, we do not need to delete it
SkASSERT(codec);
streamDeleter.detach();
return codec;
}
return NULL;
}
SkJpegCodec::SkJpegCodec(const SkImageInfo& srcInfo, SkStream* stream,
JpegDecoderMgr* decoderMgr)
: INHERITED(srcInfo, stream)
, fDecoderMgr(decoderMgr)
{}
/*
* 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 = DSTATE_READY;
dinfo.num_components = 0;
dinfo.scale_num = num;
dinfo.scale_denom = denom;
chromium_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 = NULL;
if (!ReadHeader(this->stream(), NULL, &decoderMgr)) {
return fDecoderMgr->returnFalse("could not rewind");
}
SkASSERT(NULL != 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 scale to the requested dimensions and scales the dimensions
* if possible
*/
bool SkJpegCodec::scaleToDimensions(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;
chromium_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) {
return fDecoderMgr->returnFalse("could not scale to requested dimensions");
}
// Try the next scale
fDecoderMgr->dinfo()->scale_num -= 1;
chromium_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->scaleToDimensions(dstInfo.width(), dstInfo.height())) {
return fDecoderMgr->returnFailure("cannot scale to requested dims", kInvalidScale);
}
// Now, given valid output dimensions, we can start the decompress
if (!chromium_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 = chromium_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.
if (kNo_ZeroInitialized == options.fZeroInitialized ||
kN32_SkColorType == dstInfo.colorType()) {
SkSwizzler::Fill(dstRow, dstInfo, dstRowBytes, dstHeight - y,
SK_ColorBLACK, NULL);
}
// Prevent libjpeg from failing on incomplete decode
dinfo->output_scanline = dstHeight;
// Finish the decode and indicate that the input was incomplete.
chromium_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);
}
chromium_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()
{}
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->scaleToDimensions(dstInfo.width(), dstInfo.height())) {
return SkCodec::kInvalidScale;
}
// Now, given valid output dimensions, we can start the decompress
if (!chromium_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();
chromium_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 = (JSAMPLE*) dst;
for (int y = 0; y < count; y++) {
// Read row of the image
uint32_t rowsDecoded =
chromium_jpeg_read_scanlines(fCodec->fDecoderMgr->dinfo(), &dstRow, 1);
if (rowsDecoded != 1) {
if (SkCodec::kNo_ZeroInitialized == fOpts.fZeroInitialized ||
kN32_SkColorType == this->dstInfo().colorType()) {
SkSwizzler::Fill(dstRow, this->dstInfo(), rowBytes,
count - y, SK_ColorBLACK, NULL);
}
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, this->dstInfo().width());
}
// Move to the next row
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 chromium_jpeg_skip_scanlines(dinfo, count) \
SkAutoMalloc storage(dinfo->output_width * dinfo->out_color_components); \
uint8_t* storagePtr = static_cast<uint8_t*>(storage.get()); \
for (int y = 0; y < count; y++) { \
chromium_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);
}
chromium_jpeg_skip_scanlines(fCodec->fDecoderMgr->dinfo(), count);
return SkCodec::kSuccess;
}
#ifndef TURBO_HAS_SKIP
#undef chromium_jpeg_skip_scanlines
#endif
private:
SkAutoTDelete<SkJpegCodec> fCodec;
SkCodec::Options fOpts;
typedef SkScanlineDecoder INHERITED;
};
SkScanlineDecoder* SkJpegCodec::NewSDFromStream(SkStream* stream) {
SkAutoTDelete<SkJpegCodec> codec(static_cast<SkJpegCodec*>(SkJpegCodec::NewFromStream(stream)));
if (!codec) {
return NULL;
}
const SkImageInfo& srcInfo = codec->getInfo();
// Return the new scanline decoder
return SkNEW_ARGS(SkJpegScanlineDecoder, (srcInfo, codec.detach()));
}