blob: 067a76f4e7c16b5cb8a39518ea251f4654279f11 [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 "client_utils/android/BitmapRegionDecoder.h"
#include "client_utils/android/BitmapRegionDecoderPriv.h"
#include "include/codec/SkAndroidCodec.h"
#include "include/core/SkEncodedImageFormat.h"
#include "src/codec/SkCodecPriv.h"
namespace android {
namespace skia {
std::unique_ptr<BitmapRegionDecoder> BitmapRegionDecoder::Make(sk_sp<SkData> data) {
auto codec = SkAndroidCodec::MakeFromData(std::move(data));
if (nullptr == codec) {
SkCodecPrintf("Error: Failed to create codec.\n");
return nullptr;
switch (codec->getEncodedFormat()) {
case SkEncodedImageFormat::kJPEG:
case SkEncodedImageFormat::kJPEGR:
case SkEncodedImageFormat::kPNG:
case SkEncodedImageFormat::kWEBP:
case SkEncodedImageFormat::kHEIF:
return nullptr;
return std::unique_ptr<BitmapRegionDecoder>(new BitmapRegionDecoder(std::move(codec)));
BitmapRegionDecoder::BitmapRegionDecoder(std::unique_ptr<SkAndroidCodec> codec)
: fCodec(std::move(codec))
int BitmapRegionDecoder::width() const {
return fCodec->getInfo().width();
int BitmapRegionDecoder::height() const {
return fCodec->getInfo().height();
bool BitmapRegionDecoder::decodeRegion(SkBitmap* bitmap, BRDAllocator* allocator,
const SkIRect& desiredSubset, int sampleSize, SkColorType dstColorType,
bool requireUnpremul, sk_sp<SkColorSpace> dstColorSpace) {
// Fix the input sampleSize if necessary.
if (sampleSize < 1) {
sampleSize = 1;
// The size of the output bitmap is determined by the size of the
// requested subset, not by the size of the intersection of the subset
// and the image dimensions.
// If inputX is negative, we will need to place decoded pixels into the
// output bitmap starting at a left offset. Call this outX.
// If outX is non-zero, subsetX must be zero.
// If inputY is negative, we will need to place decoded pixels into the
// output bitmap starting at a top offset. Call this outY.
// If outY is non-zero, subsetY must be zero.
int outX;
int outY;
SkIRect subset = desiredSubset;
SubsetType type = adjust_subset_rect(fCodec->getInfo().dimensions(), &subset, &outX, &outY);
if (SubsetType::kOutside_SubsetType == type) {
return false;
// Ask the codec for a scaled subset
if (!fCodec->getSupportedSubset(&subset)) {
SkCodecPrintf("Error: Could not get subset.\n");
return false;
SkISize scaledSize = fCodec->getSampledSubsetDimensions(sampleSize, subset);
// Create the image info for the decode
SkAlphaType dstAlphaType = fCodec->computeOutputAlphaType(requireUnpremul);
SkImageInfo decodeInfo =
SkImageInfo::Make(scaledSize, dstColorType, dstAlphaType, dstColorSpace);
// Initialize the destination bitmap
int scaledOutX = 0;
int scaledOutY = 0;
int scaledOutWidth = scaledSize.width();
int scaledOutHeight = scaledSize.height();
if (SubsetType::kPartiallyInside_SubsetType == type) {
scaledOutX = outX / sampleSize;
scaledOutY = outY / sampleSize;
// We need to be safe here because getSupportedSubset() may have modified the subset.
const int extraX = std::max(0, desiredSubset.width() - outX - subset.width());
const int extraY = std::max(0, desiredSubset.height() - outY - subset.height());
const int scaledExtraX = extraX / sampleSize;
const int scaledExtraY = extraY / sampleSize;
scaledOutWidth += scaledOutX + scaledExtraX;
scaledOutHeight += scaledOutY + scaledExtraY;
SkImageInfo outInfo = decodeInfo.makeWH(scaledOutWidth, scaledOutHeight);
if (kGray_8_SkColorType == dstColorType) {
// The legacy implementations of BitmapFactory and BitmapRegionDecoder
// used kAlpha8 for grayscale images (before kGray8 existed). While
// the codec recognizes kGray8, we need to decode into a kAlpha8
// bitmap in order to avoid a behavior change.
outInfo = outInfo.makeColorType(kAlpha_8_SkColorType).makeAlphaType(kPremul_SkAlphaType);
if (!bitmap->tryAllocPixels(allocator)) {
SkCodecPrintf("Error: Could not allocate pixels.\n");
return false;
// Zero the bitmap if the region is not completely within the image.
// TODO (msarett): Can we make this faster by implementing it to only
// zero parts of the image that we won't overwrite with
// pixels?
SkCodec::ZeroInitialized zeroInit = allocator ? allocator->zeroInit() :
if (SubsetType::kPartiallyInside_SubsetType == type &&
SkCodec::kNo_ZeroInitialized == zeroInit) {
void* pixels = bitmap->getPixels();
size_t bytes = outInfo.computeByteSize(bitmap->rowBytes());
memset(pixels, 0, bytes);
// Decode into the destination bitmap
SkAndroidCodec::AndroidOptions options;
options.fSampleSize = sampleSize;
options.fSubset = &subset;
options.fZeroInitialized = zeroInit;
void* dst = bitmap->getAddr(scaledOutX, scaledOutY);
SkCodec::Result result = fCodec->getAndroidPixels(decodeInfo, dst, bitmap->rowBytes(),
switch (result) {
case SkCodec::kSuccess:
case SkCodec::kIncompleteInput:
case SkCodec::kErrorInInput:
return true;
SkCodecPrintf("Error: Could not get pixels with message \"%s\".\n",
return false;
} // namespace skia
} // namespace android