/*
* 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 "SkAndroidCodec.h"
#include "SkCodec.h"
#include "SkCodecPriv.h"
#include "SkMakeUnique.h"
#include "SkPixmap.h"
#include "SkPixmapPriv.h"
#include "SkRawAdapterCodec.h"
#include "SkSampledCodec.h"
#include "SkWebpAdapterCodec.h"
static bool is_valid_sample_size(int sampleSize) {
// FIXME: As Leon has mentioned elsewhere, surely there is also a maximum sampleSize?
return sampleSize > 0;
}
/**
* Loads the gamut as a set of three points (triangle).
*/
static void load_gamut(SkPoint rgb[], const SkMatrix44& xyz) {
// rx = rX / (rX + rY + rZ)
// ry = rY / (rX + rY + rZ)
// gx, gy, bx, and gy are calulcated similarly.
for (int rgbIdx = 0; rgbIdx < 3; rgbIdx++) {
float sum = xyz.get(0, rgbIdx) + xyz.get(1, rgbIdx) + xyz.get(2, rgbIdx);
rgb[rgbIdx].fX = xyz.get(0, rgbIdx) / sum;
rgb[rgbIdx].fY = xyz.get(1, rgbIdx) / sum;
}
}
/**
* Calculates the area of the triangular gamut.
*/
static float calculate_area(SkPoint abc[]) {
SkPoint a = abc[0];
SkPoint b = abc[1];
SkPoint c = abc[2];
return 0.5f * SkTAbs(a.fX*b.fY + b.fX*c.fY - a.fX*c.fY - c.fX*b.fY - b.fX*a.fY);
}
static constexpr float kSRGB_D50_GamutArea = 0.084f;
static bool is_wide_gamut(const SkColorSpace* colorSpace) {
// Determine if the source image has a gamut that is wider than sRGB. If so, we
// will use P3 as the output color space to avoid clipping the gamut.
const SkMatrix44* toXYZD50 = colorSpace->toXYZD50();
if (toXYZD50) {
SkPoint rgb[3];
load_gamut(rgb, *toXYZD50);
return calculate_area(rgb) > kSRGB_D50_GamutArea;
}
return false;
}
static inline SkImageInfo adjust_info(SkCodec* codec,
SkAndroidCodec::ExifOrientationBehavior orientationBehavior) {
auto info = codec->getInfo();
if (orientationBehavior == SkAndroidCodec::ExifOrientationBehavior::kIgnore
|| !SkPixmapPriv::ShouldSwapWidthHeight(codec->getOrigin())) {
return info;
}
return SkPixmapPriv::SwapWidthHeight(info);
}
SkAndroidCodec::SkAndroidCodec(SkCodec* codec, ExifOrientationBehavior orientationBehavior)
: fInfo(adjust_info(codec, orientationBehavior))
, fOrientationBehavior(orientationBehavior)
, fCodec(codec)
{}
SkAndroidCodec::~SkAndroidCodec() {}
std::unique_ptr<SkAndroidCodec> SkAndroidCodec::MakeFromStream(std::unique_ptr<SkStream> stream,
SkPngChunkReader* chunkReader) {
auto codec = SkCodec::MakeFromStream(std::move(stream), nullptr, chunkReader);
return MakeFromCodec(std::move(codec));
}
std::unique_ptr<SkAndroidCodec> SkAndroidCodec::MakeFromCodec(std::unique_ptr<SkCodec> codec,
ExifOrientationBehavior orientationBehavior) {
if (nullptr == codec) {
return nullptr;
}
switch ((SkEncodedImageFormat)codec->getEncodedFormat()) {
#ifdef SK_HAS_PNG_LIBRARY
case SkEncodedImageFormat::kPNG:
case SkEncodedImageFormat::kICO:
#endif
#ifdef SK_HAS_JPEG_LIBRARY
case SkEncodedImageFormat::kJPEG:
#endif
case SkEncodedImageFormat::kGIF:
case SkEncodedImageFormat::kBMP:
case SkEncodedImageFormat::kWBMP:
#ifdef SK_HAS_HEIF_LIBRARY
case SkEncodedImageFormat::kHEIF:
#endif
return skstd::make_unique<SkSampledCodec>(codec.release(), orientationBehavior);
#ifdef SK_HAS_WEBP_LIBRARY
case SkEncodedImageFormat::kWEBP:
return skstd::make_unique<SkWebpAdapterCodec>((SkWebpCodec*) codec.release(),
orientationBehavior);
#endif
#ifdef SK_CODEC_DECODES_RAW
case SkEncodedImageFormat::kDNG:
return skstd::make_unique<SkRawAdapterCodec>((SkRawCodec*)codec.release(),
orientationBehavior);
#endif
default:
return nullptr;
}
}
std::unique_ptr<SkAndroidCodec> SkAndroidCodec::MakeFromData(sk_sp<SkData> data,
SkPngChunkReader* chunkReader) {
if (!data) {
return nullptr;
}
return MakeFromStream(SkMemoryStream::Make(std::move(data)), chunkReader);
}
SkColorType SkAndroidCodec::computeOutputColorType(SkColorType requestedColorType) {
bool highPrecision = fCodec->getEncodedInfo().bitsPerComponent() > 8;
switch (requestedColorType) {
case kARGB_4444_SkColorType:
return kN32_SkColorType;
case kN32_SkColorType:
break;
case kAlpha_8_SkColorType:
// Fall through to kGray_8. Before kGray_8_SkColorType existed,
// we allowed clients to request kAlpha_8 when they wanted a
// grayscale decode.
case kGray_8_SkColorType:
if (kGray_8_SkColorType == this->getInfo().colorType()) {
return kGray_8_SkColorType;
}
break;
case kRGB_565_SkColorType:
if (kOpaque_SkAlphaType == this->getInfo().alphaType()) {
return kRGB_565_SkColorType;
}
break;
case kRGBA_F16_SkColorType:
return kRGBA_F16_SkColorType;
default:
break;
}
// F16 is the Android default for high precision images.
return highPrecision ? kRGBA_F16_SkColorType : kN32_SkColorType;
}
SkAlphaType SkAndroidCodec::computeOutputAlphaType(bool requestedUnpremul) {
if (kOpaque_SkAlphaType == this->getInfo().alphaType()) {
return kOpaque_SkAlphaType;
}
return requestedUnpremul ? kUnpremul_SkAlphaType : kPremul_SkAlphaType;
}
sk_sp<SkColorSpace> SkAndroidCodec::computeOutputColorSpace(SkColorType outputColorType,
sk_sp<SkColorSpace> prefColorSpace) {
switch (outputColorType) {
case kRGBA_8888_SkColorType:
case kBGRA_8888_SkColorType: {
// If |prefColorSpace| is supported, choose it.
SkColorSpaceTransferFn fn;
if (prefColorSpace && prefColorSpace->isNumericalTransferFn(&fn)) {
return prefColorSpace;
}
SkColorSpace* encodedSpace = fCodec->getInfo().colorSpace();
if (encodedSpace->isNumericalTransferFn(&fn)) {
// Leave the pixels in the encoded color space. Color space conversion
// will be handled after decode time.
return sk_ref_sp(encodedSpace);
}
if (is_wide_gamut(encodedSpace)) {
return SkColorSpace::MakeRGB(SkColorSpace::kSRGB_RenderTargetGamma,
SkColorSpace::kDCIP3_D65_Gamut);
}
return SkColorSpace::MakeSRGB();
}
case kRGBA_F16_SkColorType:
// Note that |prefColorSpace| is ignored, F16 is always linear sRGB.
return SkColorSpace::MakeSRGBLinear();
case kRGB_565_SkColorType:
// Note that |prefColorSpace| is ignored, 565 is always sRGB.
return SkColorSpace::MakeSRGB();
default:
// Color correction not supported for kGray.
return nullptr;
}
}
static bool supports_any_down_scale(const SkCodec* codec) {
return codec->getEncodedFormat() == SkEncodedImageFormat::kWEBP;
}
// There are a variety of ways two SkISizes could be compared. This method
// returns true if either dimensions of a is < that of b.
// computeSampleSize also uses the opposite, which means that both
// dimensions of a >= b.
static inline bool smaller_than(const SkISize& a, const SkISize& b) {
return a.width() < b.width() || a.height() < b.height();
}
// Both dimensions of a > that of b.
static inline bool strictly_bigger_than(const SkISize& a, const SkISize& b) {
return a.width() > b.width() && a.height() > b.height();
}
int SkAndroidCodec::computeSampleSize(SkISize* desiredSize) const {
SkASSERT(desiredSize);
if (!desiredSize || *desiredSize == fInfo.dimensions()) {
return 1;
}
if (smaller_than(fInfo.dimensions(), *desiredSize)) {
*desiredSize = fInfo.dimensions();
return 1;
}
// Handle bad input:
if (desiredSize->width() < 1 || desiredSize->height() < 1) {
*desiredSize = SkISize::Make(std::max(1, desiredSize->width()),
std::max(1, desiredSize->height()));
}
if (supports_any_down_scale(fCodec.get())) {
return 1;
}
int sampleX = fInfo.width() / desiredSize->width();
int sampleY = fInfo.height() / desiredSize->height();
int sampleSize = std::min(sampleX, sampleY);
auto computedSize = this->getSampledDimensions(sampleSize);
if (computedSize == *desiredSize) {
return sampleSize;
}
if (computedSize == fInfo.dimensions() || sampleSize == 1) {
// Cannot downscale
*desiredSize = computedSize;
return 1;
}
if (strictly_bigger_than(computedSize, *desiredSize)) {
// See if there is a tighter fit.
while (true) {
auto smaller = this->getSampledDimensions(sampleSize + 1);
if (smaller == *desiredSize) {
return sampleSize + 1;
}
if (smaller == computedSize || smaller_than(smaller, *desiredSize)) {
// Cannot get any smaller without being smaller than desired.
*desiredSize = computedSize;
return sampleSize;
}
sampleSize++;
computedSize = smaller;
}
SkASSERT(false);
}
if (!smaller_than(computedSize, *desiredSize)) {
// This means one of the computed dimensions is equal to desired, and
// the other is bigger. This is as close as we can get.
*desiredSize = computedSize;
return sampleSize;
}
// computedSize is too small. Make it larger.
while (sampleSize > 2) {
auto bigger = this->getSampledDimensions(sampleSize - 1);
if (bigger == *desiredSize || !smaller_than(bigger, *desiredSize)) {
*desiredSize = bigger;
return sampleSize - 1;
}
sampleSize--;
}
*desiredSize = fInfo.dimensions();
return 1;
}
SkISize SkAndroidCodec::getSampledDimensions(int sampleSize) const {
if (!is_valid_sample_size(sampleSize)) {
return {0, 0};
}
// Fast path for when we are not scaling.
if (1 == sampleSize) {
return fInfo.dimensions();
}
return this->onGetSampledDimensions(sampleSize);
}
bool SkAndroidCodec::getSupportedSubset(SkIRect* desiredSubset) const {
if (!desiredSubset || !is_valid_subset(*desiredSubset, fInfo.dimensions())) {
return false;
}
return this->onGetSupportedSubset(desiredSubset);
}
SkISize SkAndroidCodec::getSampledSubsetDimensions(int sampleSize, const SkIRect& subset) const {
if (!is_valid_sample_size(sampleSize)) {
return {0, 0};
}
// We require that the input subset is a subset that is supported by SkAndroidCodec.
// We test this by calling getSupportedSubset() and verifying that no modifications
// are made to the subset.
SkIRect copySubset = subset;
if (!this->getSupportedSubset(©Subset) || copySubset != subset) {
return {0, 0};
}
// If the subset is the entire image, for consistency, use getSampledDimensions().
if (fInfo.dimensions() == subset.size()) {
return this->getSampledDimensions(sampleSize);
}
// This should perhaps call a virtual function, but currently both of our subclasses
// want the same implementation.
return {get_scaled_dimension(subset.width(), sampleSize),
get_scaled_dimension(subset.height(), sampleSize)};
}
static bool acceptable_result(SkCodec::Result result) {
switch (result) {
// These results mean a partial or complete image. They should be considered
// a success by SkPixmapPriv.
case SkCodec::kSuccess:
case SkCodec::kIncompleteInput:
case SkCodec::kErrorInInput:
return true;
default:
return false;
}
}
SkCodec::Result SkAndroidCodec::getAndroidPixels(const SkImageInfo& requestInfo,
void* requestPixels, size_t requestRowBytes, const AndroidOptions* options) {
if (!requestPixels) {
return SkCodec::kInvalidParameters;
}
if (requestRowBytes < requestInfo.minRowBytes()) {
return SkCodec::kInvalidParameters;
}
SkImageInfo adjustedInfo = fInfo;
if (ExifOrientationBehavior::kRespect == fOrientationBehavior
&& SkPixmapPriv::ShouldSwapWidthHeight(fCodec->getOrigin())) {
adjustedInfo = SkPixmapPriv::SwapWidthHeight(adjustedInfo);
}
AndroidOptions defaultOptions;
if (!options) {
options = &defaultOptions;
} else if (options->fSubset) {
if (!is_valid_subset(*options->fSubset, adjustedInfo.dimensions())) {
return SkCodec::kInvalidParameters;
}
if (SkIRect::MakeSize(adjustedInfo.dimensions()) == *options->fSubset) {
// The caller wants the whole thing, rather than a subset. Modify
// the AndroidOptions passed to onGetAndroidPixels to not specify
// a subset.
defaultOptions = *options;
defaultOptions.fSubset = nullptr;
options = &defaultOptions;
}
}
if (ExifOrientationBehavior::kIgnore == fOrientationBehavior) {
return this->onGetAndroidPixels(requestInfo, requestPixels, requestRowBytes, *options);
}
SkCodec::Result result;
auto decode = [this, options, &result](const SkPixmap& pm) {
result = this->onGetAndroidPixels(pm.info(), pm.writable_addr(), pm.rowBytes(), *options);
return acceptable_result(result);
};
SkPixmap dst(requestInfo, requestPixels, requestRowBytes);
if (SkPixmapPriv::Orient(dst, fCodec->getOrigin(), decode)) {
return result;
}
// Orient returned false. If onGetAndroidPixels succeeded, then Orient failed internally.
if (acceptable_result(result)) {
return SkCodec::kInternalError;
}
return result;
}
SkCodec::Result SkAndroidCodec::getAndroidPixels(const SkImageInfo& info, void* pixels,
size_t rowBytes) {
return this->getAndroidPixels(info, pixels, rowBytes, nullptr);
}