/*
* 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 "SkBmpCodec.h"
#include "SkCodec.h"
#include "SkCodecPriv.h"
#include "SkColorSpace.h"
#include "SkColorSpaceXform_Base.h"
#include "SkData.h"
#include "SkGifCodec.h"
#include "SkHalf.h"
#include "SkIcoCodec.h"
#include "SkJpegCodec.h"
#ifdef SK_HAS_PNG_LIBRARY
#include "SkPngCodec.h"
#endif
#include "SkRawCodec.h"
#include "SkStream.h"
#include "SkWbmpCodec.h"
#include "SkWebpCodec.h"
struct DecoderProc {
bool (*IsFormat)(const void*, size_t);
SkCodec* (*NewFromStream)(SkStream*);
};
static const DecoderProc gDecoderProcs[] = {
#ifdef SK_HAS_JPEG_LIBRARY
{ SkJpegCodec::IsJpeg, SkJpegCodec::NewFromStream },
#endif
#ifdef SK_HAS_WEBP_LIBRARY
{ SkWebpCodec::IsWebp, SkWebpCodec::NewFromStream },
#endif
{ SkGifCodec::IsGif, SkGifCodec::NewFromStream },
#ifdef SK_HAS_PNG_LIBRARY
{ SkIcoCodec::IsIco, SkIcoCodec::NewFromStream },
#endif
{ SkBmpCodec::IsBmp, SkBmpCodec::NewFromStream },
{ SkWbmpCodec::IsWbmp, SkWbmpCodec::NewFromStream }
};
size_t SkCodec::MinBufferedBytesNeeded() {
return WEBP_VP8_HEADER_SIZE;
}
SkCodec* SkCodec::NewFromStream(SkStream* stream,
SkPngChunkReader* chunkReader) {
if (!stream) {
return nullptr;
}
std::unique_ptr<SkStream> streamDeleter(stream);
// 14 is enough to read all of the supported types.
const size_t bytesToRead = 14;
SkASSERT(bytesToRead <= MinBufferedBytesNeeded());
char buffer[bytesToRead];
size_t bytesRead = stream->peek(buffer, bytesToRead);
// It is also possible to have a complete image less than bytesToRead bytes
// (e.g. a 1 x 1 wbmp), meaning peek() would return less than bytesToRead.
// Assume that if bytesRead < bytesToRead, but > 0, the stream is shorter
// than bytesToRead, so pass that directly to the decoder.
// It also is possible the stream uses too small a buffer for peeking, but
// we trust the caller to use a large enough buffer.
if (0 == bytesRead) {
// TODO: After implementing peek in CreateJavaOutputStreamAdaptor.cpp, this
// printf could be useful to notice failures.
// SkCodecPrintf("Encoded image data failed to peek!\n");
// It is possible the stream does not support peeking, but does support
// rewinding.
// Attempt to read() and pass the actual amount read to the decoder.
bytesRead = stream->read(buffer, bytesToRead);
if (!stream->rewind()) {
SkCodecPrintf("Encoded image data could not peek or rewind to determine format!\n");
return nullptr;
}
}
// PNG is special, since we want to be able to supply an SkPngChunkReader.
// But this code follows the same pattern as the loop.
#ifdef SK_HAS_PNG_LIBRARY
if (SkPngCodec::IsPng(buffer, bytesRead)) {
return SkPngCodec::NewFromStream(streamDeleter.release(), chunkReader);
} else
#endif
{
for (DecoderProc proc : gDecoderProcs) {
if (proc.IsFormat(buffer, bytesRead)) {
return proc.NewFromStream(streamDeleter.release());
}
}
#ifdef SK_CODEC_DECODES_RAW
// Try to treat the input as RAW if all the other checks failed.
return SkRawCodec::NewFromStream(streamDeleter.release());
#endif
}
return nullptr;
}
SkCodec* SkCodec::NewFromData(sk_sp<SkData> data, SkPngChunkReader* reader) {
if (!data) {
return nullptr;
}
return NewFromStream(new SkMemoryStream(data), reader);
}
SkCodec::SkCodec(int width, int height, const SkEncodedInfo& info, SkStream* stream,
sk_sp<SkColorSpace> colorSpace, Origin origin)
: fEncodedInfo(info)
, fSrcInfo(info.makeImageInfo(width, height, std::move(colorSpace)))
, fStream(stream)
, fNeedsRewind(false)
, fOrigin(origin)
, fDstInfo()
, fOptions()
, fCurrScanline(-1)
{}
SkCodec::SkCodec(const SkEncodedInfo& info, const SkImageInfo& imageInfo, SkStream* stream,
Origin origin)
: fEncodedInfo(info)
, fSrcInfo(imageInfo)
, fStream(stream)
, fNeedsRewind(false)
, fOrigin(origin)
, fDstInfo()
, fOptions()
, fCurrScanline(-1)
{}
SkCodec::~SkCodec() {}
bool SkCodec::rewindIfNeeded() {
// Store the value of fNeedsRewind so we can update it. Next read will
// require a rewind.
const bool needsRewind = fNeedsRewind;
fNeedsRewind = true;
if (!needsRewind) {
return true;
}
// startScanlineDecode will need to be called before decoding scanlines.
fCurrScanline = -1;
// startIncrementalDecode will need to be called before incrementalDecode.
fStartedIncrementalDecode = false;
// Some codecs do not have a stream. They may hold onto their own data or another codec.
// They must handle rewinding themselves.
if (fStream && !fStream->rewind()) {
return false;
}
return this->onRewind();
}
#define CHECK_COLOR_TABLE \
if (kIndex_8_SkColorType == info.colorType()) { \
if (nullptr == ctable || nullptr == ctableCount) { \
return SkCodec::kInvalidParameters; \
} \
} else { \
if (ctableCount) { \
*ctableCount = 0; \
} \
ctableCount = nullptr; \
ctable = nullptr; \
}
SkCodec::Result SkCodec::getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
const Options* options, SkPMColor ctable[], int* ctableCount) {
if (kUnknown_SkColorType == info.colorType()) {
return kInvalidConversion;
}
if (nullptr == pixels) {
return kInvalidParameters;
}
if (rowBytes < info.minRowBytes()) {
return kInvalidParameters;
}
CHECK_COLOR_TABLE;
if (!this->rewindIfNeeded()) {
return kCouldNotRewind;
}
// Default options.
Options optsStorage;
if (nullptr == options) {
options = &optsStorage;
} else if (options->fSubset) {
SkIRect subset(*options->fSubset);
if (!this->onGetValidSubset(&subset) || subset != *options->fSubset) {
// FIXME: How to differentiate between not supporting subset at all
// and not supporting this particular subset?
return kUnimplemented;
}
}
// FIXME: Support subsets somehow? Note that this works for SkWebpCodec
// because it supports arbitrary scaling/subset combinations.
if (!this->dimensionsSupported(info.dimensions())) {
return kInvalidScale;
}
fDstInfo = info;
fOptions = *options;
// On an incomplete decode, the subclass will specify the number of scanlines that it decoded
// successfully.
int rowsDecoded = 0;
const Result result = this->onGetPixels(info, pixels, rowBytes, *options, ctable, ctableCount,
&rowsDecoded);
if ((kIncompleteInput == result || kSuccess == result) && ctableCount) {
SkASSERT(*ctableCount >= 0 && *ctableCount <= 256);
}
// A return value of kIncompleteInput indicates a truncated image stream.
// In this case, we will fill any uninitialized memory with a default value.
// Some subclasses will take care of filling any uninitialized memory on
// their own. They indicate that all of the memory has been filled by
// setting rowsDecoded equal to the height.
if (kIncompleteInput == result && rowsDecoded != info.height()) {
// FIXME: (skbug.com/5772) fillIncompleteImage will fill using the swizzler's width, unless
// there is a subset. In that case, it will use the width of the subset. From here, the
// subset will only be non-null in the case of SkWebpCodec, but it treats the subset
// differenty from the other codecs, and it needs to use the width specified by the info.
// Set the subset to null so SkWebpCodec uses the correct width.
fOptions.fSubset = nullptr;
this->fillIncompleteImage(info, pixels, rowBytes, options->fZeroInitialized, info.height(),
rowsDecoded);
}
return result;
}
SkCodec::Result SkCodec::getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes) {
return this->getPixels(info, pixels, rowBytes, nullptr, nullptr, nullptr);
}
SkCodec::Result SkCodec::startIncrementalDecode(const SkImageInfo& info, void* pixels,
size_t rowBytes, const SkCodec::Options* options, SkPMColor* ctable, int* ctableCount) {
fStartedIncrementalDecode = false;
if (kUnknown_SkColorType == info.colorType()) {
return kInvalidConversion;
}
if (nullptr == pixels) {
return kInvalidParameters;
}
// Ensure that valid color ptrs are passed in for kIndex8 color type
CHECK_COLOR_TABLE;
// FIXME: If the rows come after the rows of a previous incremental decode,
// we might be able to skip the rewind, but only the implementation knows
// that. (e.g. PNG will always need to rewind, since we called longjmp, but
// a bottom-up BMP could skip rewinding if the new rows are above the old
// rows.)
if (!this->rewindIfNeeded()) {
return kCouldNotRewind;
}
// Set options.
Options optsStorage;
if (nullptr == options) {
options = &optsStorage;
} else if (options->fSubset) {
SkIRect size = SkIRect::MakeSize(info.dimensions());
if (!size.contains(*options->fSubset)) {
return kInvalidParameters;
}
const int top = options->fSubset->top();
const int bottom = options->fSubset->bottom();
if (top < 0 || top >= info.height() || top >= bottom || bottom > info.height()) {
return kInvalidParameters;
}
}
if (!this->dimensionsSupported(info.dimensions())) {
return kInvalidScale;
}
fDstInfo = info;
fOptions = *options;
const Result result = this->onStartIncrementalDecode(info, pixels, rowBytes,
fOptions, ctable, ctableCount);
if (kSuccess == result) {
fStartedIncrementalDecode = true;
} else if (kUnimplemented == result) {
// FIXME: This is temporarily necessary, until we transition SkCodec
// implementations from scanline decoding to incremental decoding.
// SkAndroidCodec will first attempt to use incremental decoding, but
// will fall back to scanline decoding if incremental returns
// kUnimplemented. rewindIfNeeded(), above, set fNeedsRewind to true
// (after potentially rewinding), but we do not want the next call to
// startScanlineDecode() to do a rewind.
fNeedsRewind = false;
}
return result;
}
SkCodec::Result SkCodec::startScanlineDecode(const SkImageInfo& info,
const SkCodec::Options* options, SkPMColor ctable[], int* ctableCount) {
// Reset fCurrScanline in case of failure.
fCurrScanline = -1;
// Ensure that valid color ptrs are passed in for kIndex8 color type
CHECK_COLOR_TABLE;
if (!this->rewindIfNeeded()) {
return kCouldNotRewind;
}
// Set options.
Options optsStorage;
if (nullptr == options) {
options = &optsStorage;
} else if (options->fSubset) {
SkIRect size = SkIRect::MakeSize(info.dimensions());
if (!size.contains(*options->fSubset)) {
return kInvalidInput;
}
// We only support subsetting in the x-dimension for scanline decoder.
// Subsetting in the y-dimension can be accomplished using skipScanlines().
if (options->fSubset->top() != 0 || options->fSubset->height() != info.height()) {
return kInvalidInput;
}
}
// FIXME: Support subsets somehow?
if (!this->dimensionsSupported(info.dimensions())) {
return kInvalidScale;
}
const Result result = this->onStartScanlineDecode(info, *options, ctable, ctableCount);
if (result != SkCodec::kSuccess) {
return result;
}
fCurrScanline = 0;
fDstInfo = info;
fOptions = *options;
return kSuccess;
}
#undef CHECK_COLOR_TABLE
SkCodec::Result SkCodec::startScanlineDecode(const SkImageInfo& info) {
return this->startScanlineDecode(info, nullptr, nullptr, nullptr);
}
int SkCodec::getScanlines(void* dst, int countLines, size_t rowBytes) {
if (fCurrScanline < 0) {
return 0;
}
SkASSERT(!fDstInfo.isEmpty());
if (countLines <= 0 || fCurrScanline + countLines > fDstInfo.height()) {
return 0;
}
const int linesDecoded = this->onGetScanlines(dst, countLines, rowBytes);
if (linesDecoded < countLines) {
this->fillIncompleteImage(this->dstInfo(), dst, rowBytes, this->options().fZeroInitialized,
countLines, linesDecoded);
}
fCurrScanline += countLines;
return linesDecoded;
}
bool SkCodec::skipScanlines(int countLines) {
if (fCurrScanline < 0) {
return false;
}
SkASSERT(!fDstInfo.isEmpty());
if (countLines < 0 || fCurrScanline + countLines > fDstInfo.height()) {
// Arguably, we could just skip the scanlines which are remaining,
// and return true. We choose to return false so the client
// can catch their bug.
return false;
}
bool result = this->onSkipScanlines(countLines);
fCurrScanline += countLines;
return result;
}
int SkCodec::outputScanline(int inputScanline) const {
SkASSERT(0 <= inputScanline && inputScanline < this->getInfo().height());
return this->onOutputScanline(inputScanline);
}
int SkCodec::onOutputScanline(int inputScanline) const {
switch (this->getScanlineOrder()) {
case kTopDown_SkScanlineOrder:
return inputScanline;
case kBottomUp_SkScanlineOrder:
return this->getInfo().height() - inputScanline - 1;
default:
// This case indicates an interlaced gif and is implemented by SkGifCodec.
SkASSERT(false);
return 0;
}
}
uint64_t SkCodec::onGetFillValue(const SkImageInfo& dstInfo) const {
switch (dstInfo.colorType()) {
case kRGBA_F16_SkColorType: {
static constexpr uint64_t transparentColor = 0;
static constexpr uint64_t opaqueColor = ((uint64_t) SK_Half1) << 48;
return (kOpaque_SkAlphaType == fSrcInfo.alphaType()) ? opaqueColor : transparentColor;
}
default: {
// This not only handles the kN32 case, but also k565, kGray8, kIndex8, since
// the low bits are zeros.
return (kOpaque_SkAlphaType == fSrcInfo.alphaType()) ?
SK_ColorBLACK : SK_ColorTRANSPARENT;
}
}
}
static void fill_proc(const SkImageInfo& info, void* dst, size_t rowBytes,
uint64_t colorOrIndex, SkCodec::ZeroInitialized zeroInit, SkSampler* sampler) {
if (sampler) {
sampler->fill(info, dst, rowBytes, colorOrIndex, zeroInit);
} else {
SkSampler::Fill(info, dst, rowBytes, colorOrIndex, zeroInit);
}
}
void SkCodec::fillIncompleteImage(const SkImageInfo& info, void* dst, size_t rowBytes,
ZeroInitialized zeroInit, int linesRequested, int linesDecoded) {
void* fillDst;
const uint64_t fillValue = this->getFillValue(info);
const int linesRemaining = linesRequested - linesDecoded;
SkSampler* sampler = this->getSampler(false);
int fillWidth = info.width();
if (fOptions.fSubset) {
fillWidth = fOptions.fSubset->width();
}
switch (this->getScanlineOrder()) {
case kTopDown_SkScanlineOrder: {
const SkImageInfo fillInfo = info.makeWH(fillWidth, linesRemaining);
fillDst = SkTAddOffset<void>(dst, linesDecoded * rowBytes);
fill_proc(fillInfo, fillDst, rowBytes, fillValue, zeroInit, sampler);
break;
}
case kBottomUp_SkScanlineOrder: {
fillDst = dst;
const SkImageInfo fillInfo = info.makeWH(fillWidth, linesRemaining);
fill_proc(fillInfo, fillDst, rowBytes, fillValue, zeroInit, sampler);
break;
}
}
}
bool SkCodec::initializeColorXform(const SkImageInfo& dstInfo,
SkTransferFunctionBehavior premulBehavior) {
fColorXform = nullptr;
bool needsColorCorrectPremul = needs_premul(dstInfo, fEncodedInfo) &&
SkTransferFunctionBehavior::kRespect == premulBehavior;
if (needs_color_xform(dstInfo, fSrcInfo, needsColorCorrectPremul)) {
fColorXform = SkColorSpaceXform_Base::New(fSrcInfo.colorSpace(), dstInfo.colorSpace(),
premulBehavior);
if (!fColorXform) {
return false;
}
}
return true;
}