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/*
* 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 "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.
float rSum = xyz.get(0, 0) + xyz.get(1, 0) + xyz.get(2, 0);
float gSum = xyz.get(0, 1) + xyz.get(1, 1) + xyz.get(2, 1);
float bSum = xyz.get(0, 2) + xyz.get(1, 2) + xyz.get(2, 2);
rgb[0].fX = xyz.get(0, 0) / rSum;
rgb[0].fY = xyz.get(1, 0) / rSum;
rgb[1].fX = xyz.get(0, 1) / gSum;
rgb[1].fY = xyz.get(1, 1) / gSum;
rgb[2].fX = xyz.get(0, 2) / bSum;
rgb[2].fY = xyz.get(1, 2) / bSum;
}
/**
* 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 const 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 = as_CSB(colorSpace)->toXYZD50();
if (toXYZD50) {
SkPoint rgb[3];
load_gamut(rgb, *toXYZD50);
return calculate_area(rgb) > kSRGB_D50_GamutArea;
}
return false;
}
SkAndroidCodec::SkAndroidCodec(SkCodec* codec)
: fInfo(codec->getInfo())
, fCodec(codec)
{}
SkAndroidCodec* SkAndroidCodec::NewFromStream(SkStream* stream, SkPngChunkReader* chunkReader) {
std::unique_ptr<SkCodec> codec(SkCodec::NewFromStream(stream, chunkReader));
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:
return new SkSampledCodec(codec.release());
#ifdef SK_HAS_WEBP_LIBRARY
case SkEncodedImageFormat::kWEBP:
return new SkWebpAdapterCodec((SkWebpCodec*) codec.release());
#endif
#ifdef SK_CODEC_DECODES_RAW
case SkEncodedImageFormat::kDNG:
return new SkRawAdapterCodec((SkRawCodec*)codec.release());
#endif
default:
return nullptr;
}
}
SkAndroidCodec* SkAndroidCodec::NewFromData(sk_sp<SkData> data, SkPngChunkReader* chunkReader) {
if (!data) {
return nullptr;
}
return NewFromStream(new SkMemoryStream(data), chunkReader);
}
SkColorType SkAndroidCodec::computeOutputColorType(SkColorType requestedColorType) {
// The legacy GIF and WBMP decoders always decode to kIndex_8_SkColorType.
// We will maintain this behavior when we can.
const SkColorType suggestedColorType = this->getInfo().colorType();
switch ((SkEncodedImageFormat) this->getEncodedFormat()) {
case SkEncodedImageFormat::kGIF:
if (suggestedColorType == kIndex_8_SkColorType) {
return kIndex_8_SkColorType;
}
break;
case SkEncodedImageFormat::kWBMP:
return kIndex_8_SkColorType;
default:
break;
}
bool highPrecision = fCodec->getEncodedInfo().bitsPerComponent() > 8;
switch (requestedColorType) {
case kARGB_4444_SkColorType:
return kN32_SkColorType;
case kN32_SkColorType:
// F16 is the Android default for high precision images.
return highPrecision ? kRGBA_F16_SkColorType : kN32_SkColorType;
case kIndex_8_SkColorType:
if (kIndex_8_SkColorType == suggestedColorType) {
return kIndex_8_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 == suggestedColorType) {
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;
}
// Android has limited support for kGray_8 (using kAlpha_8). We will not
// use kGray_8 for Android unless they specifically ask for it.
if (kGray_8_SkColorType == suggestedColorType) {
return kN32_SkColorType;
}
// |suggestedColorType| may be kN32_SkColorType or kIndex_8_SkColorType.
return highPrecision ? kRGBA_F16_SkColorType : suggestedColorType;
}
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) {
switch (outputColorType) {
case kRGBA_8888_SkColorType:
case kBGRA_8888_SkColorType:
case kIndex_8_SkColorType: {
SkColorSpace* encodedSpace = fCodec->getInfo().colorSpace();
SkColorSpaceTransferFn fn;
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:
return SkColorSpace::MakeSRGBLinear();
case kRGB_565_SkColorType:
return SkColorSpace::MakeSRGB();
default:
// Color correction not supported for kGray.
return nullptr;
}
}
SkISize SkAndroidCodec::getSampledDimensions(int sampleSize) const {
if (!is_valid_sample_size(sampleSize)) {
return SkISize::Make(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 SkISize::Make(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(&copySubset) || copySubset != subset) {
return SkISize::Make(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 SkISize::Make(get_scaled_dimension(subset.width(), sampleSize),
get_scaled_dimension(subset.height(), sampleSize));
}
SkCodec::Result SkAndroidCodec::getAndroidPixels(const SkImageInfo& info, void* pixels,
size_t rowBytes, const AndroidOptions* options) {
if (!pixels) {
return SkCodec::kInvalidParameters;
}
if (rowBytes < info.minRowBytes()) {
return SkCodec::kInvalidParameters;
}
AndroidOptions defaultOptions;
if (!options) {
options = &defaultOptions;
} else if (options->fSubset) {
if (!is_valid_subset(*options->fSubset, fInfo.dimensions())) {
return SkCodec::kInvalidParameters;
}
if (SkIRect::MakeSize(fInfo.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;
}
}
return this->onGetAndroidPixels(info, pixels, rowBytes, *options);
}
SkCodec::Result SkAndroidCodec::getAndroidPixels(const SkImageInfo& info, void* pixels,
size_t rowBytes) {
return this->getAndroidPixels(info, pixels, rowBytes, nullptr);
}