SkCodec.cpp | Explore in Territory

/*
 * 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 "include/codec/SkCodec.h"

#include "include/codec/SkCodecAnimation.h"
#include "include/codec/SkPixmapUtils.h"
#include "include/core/SkAlphaType.h"
#include "include/core/SkBitmap.h"
#include "include/core/SkColorPriv.h"
#include "include/core/SkColorSpace.h"
#include "include/core/SkColorType.h"
#include "include/core/SkData.h"
#include "include/core/SkImage.h" // IWYU pragma: keep
#include "include/core/SkImageInfo.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkStream.h"
#include "include/private/base/SkTemplates.h"
#include "modules/skcms/skcms.h"
#include "src/base/SkNoDestructor.h"
#include "src/codec/SkCodecPriv.h"
#include "src/codec/SkFrameHolder.h"
#include "src/codec/SkPixmapUtilsPriv.h"
#include "src/codec/SkSampler.h"

#include <string>
#include <string_view>
#include <utility>

#if !defined(SK_DISABLE_LEGACY_INIT_DECODERS)
#include "include/private/base/SkOnce.h"

#if defined(SK_CODEC_DECODES_AVIF)
#include "include/codec/SkAvifDecoder.h"
#endif

#if defined(SK_CODEC_DECODES_BMP)
#include "include/codec/SkBmpDecoder.h"
#endif

#if defined(SK_CODEC_DECODES_GIF) || defined(SK_HAS_WUFFS_LIBRARY)
#include "include/codec/SkGifDecoder.h"
#endif

#if defined(SK_HAS_HEIF_LIBRARY)
#include "include/android/SkHeifDecoder.h"
#endif

#if defined(SK_CODEC_DECODES_ICO)
#include "include/codec/SkIcoDecoder.h"
#endif

#if defined(SK_CODEC_DECODES_JPEG)
#include "include/codec/SkJpegDecoder.h"
#endif

#if defined(SK_CODEC_DECODES_JPEGXL)
#include "include/codec/SkJpegxlDecoder.h"
#endif

#if defined(SK_CODEC_DECODES_PNG)
#include "include/codec/SkPngDecoder.h"
#endif

#if defined(SK_CODEC_DECODES_RAW)
#include "include/codec/SkRawDecoder.h"
#endif

#if defined(SK_CODEC_DECODES_WBMP)
#include "include/codec/SkWbmpDecoder.h"
#endif

#if defined(SK_CODEC_DECODES_WEBP)
#include "include/codec/SkWebpDecoder.h"
#endif
#endif // !defined(SK_DISABLE_LEGACY_INIT_DECODERS)

namespace SkCodecs {
// A static variable inside a function avoids a static initializer.
// https://chromium.googlesource.com/chromium/src/+/HEAD/docs/static_initializers.md#removing-static-initializers
static std::vector<Decoder>* get_decoders_for_editing() { … }

const std::vector<Decoder>& get_decoders() { … }

void Register(Decoder d) { … }

bool HasDecoder(std::string_view id) { … }

}  // namespace SkCodecs

std::unique_ptr<SkCodec> SkCodec::MakeFromStream(
        std::unique_ptr<SkStream> stream, Result* outResult,
        SkPngChunkReader* chunkReader, SelectionPolicy selectionPolicy) { … }
std::unique_ptr<SkCodec> SkCodec::MakeFromStream(
        std::unique_ptr<SkStream> stream, SkSpan<const SkCodecs::Decoder> decoders,
        Result* outResult, SkPngChunkReader* chunkReader, SelectionPolicy selectionPolicy) { … }

std::unique_ptr<SkCodec> SkCodec::MakeFromData(sk_sp<SkData> data, SkPngChunkReader* reader) { … }
std::unique_ptr<SkCodec> SkCodec::MakeFromData(sk_sp<SkData> data,
                                               SkSpan<const SkCodecs::Decoder> decoders,
                                               SkPngChunkReader* reader) { … }

SkCodec::SkCodec(SkEncodedInfo&& info,
                 XformFormat srcFormat,
                 std::unique_ptr<SkStream> stream,
                 SkEncodedOrigin origin)
        : … { … }

SkCodec::~SkCodec() { … }

void SkCodec::setSrcXformFormat(XformFormat pixelFormat) { … }

bool SkCodec::queryYUVAInfo(const SkYUVAPixmapInfo::SupportedDataTypes& supportedDataTypes,
                            SkYUVAPixmapInfo* yuvaPixmapInfo) const { … }

SkCodec::Result SkCodec::getYUVAPlanes(const SkYUVAPixmaps& yuvaPixmaps) { … }

bool SkCodec::conversionSupported(const SkImageInfo& dst, bool srcIsOpaque, bool needsColorXform) { … }

bool SkCodec::rewindIfNeeded() { … }

static SkIRect frame_rect_on_screen(SkIRect frameRect,
                                    const SkIRect& screenRect) { … }

bool zero_rect(const SkImageInfo& dstInfo, void* pixels, size_t rowBytes,
               SkISize srcDimensions, SkIRect prevRect) { … }

SkCodec::Result SkCodec::handleFrameIndex(const SkImageInfo& info, void* pixels, size_t rowBytes,
                                          const Options& options, GetPixelsCallback getPixelsFn) { … }

SkCodec::Result SkCodec::getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes,
                                   const Options* options) { … }

std::tuple<sk_sp<SkImage>, SkCodec::Result> SkCodec::getImage(const SkImageInfo& info,
                                                              const Options* options) { … }

std::tuple<sk_sp<SkImage>, SkCodec::Result> SkCodec::getImage() { … }

SkCodec::Result SkCodec::startIncrementalDecode(const SkImageInfo& info, void* pixels,
        size_t rowBytes, const SkCodec::Options* options) { … }


SkCodec::Result SkCodec::startScanlineDecode(const SkImageInfo& info,
        const SkCodec::Options* options) { … }

int SkCodec::getScanlines(void* dst, int countLines, size_t rowBytes) { … }

bool SkCodec::skipScanlines(int countLines) { … }

int SkCodec::outputScanline(int inputScanline) const { … }

int SkCodec::onOutputScanline(int inputScanline) const { … }

void SkCodec::fillIncompleteImage(const SkImageInfo& info, void* dst, size_t rowBytes,
        ZeroInitialized zeroInit, int linesRequested, int linesDecoded) { … }

bool sk_select_xform_format(SkColorType colorType, bool forColorTable,
                            skcms_PixelFormat* outFormat) { … }

bool SkCodec::initializeColorXform(const SkImageInfo& dstInfo, SkEncodedInfo::Alpha encodedAlpha,
                                   bool srcIsOpaque) { … }

void SkCodec::applyColorXform(void* dst, const void* src, int count) const { … }

std::vector<SkCodec::FrameInfo> SkCodec::getFrameInfo() { … }

const char* SkCodec::ResultToString(Result result) { … }

void SkFrame::fillIn(SkCodec::FrameInfo* frameInfo, bool fullyReceived) const { … }

static bool independent(const SkFrame& frame) { … }

static bool restore_bg(const SkFrame& frame) { … }

// As its name suggests, this method computes a frame's alpha (e.g. completely
// opaque, unpremul, binary) and its required frame (a preceding frame that
// this frame depends on, to draw the complete image at this frame's point in
// the animation stream), and calls this frame's setter methods with that
// computed information.
//
// A required frame of kNoFrame means that this frame is independent: drawing
// the complete image at this frame's point in the animation stream does not
// require first preparing the pixel buffer based on another frame. Instead,
// drawing can start from an uninitialized pixel buffer.
//
// "Uninitialized" is from the SkCodec's caller's point of view. In the SkCodec
// implementation, for independent frames, first party Skia code (in src/codec)
// will typically fill the buffer with a uniform background color (e.g.
// transparent black) before calling into third party codec-specific code (e.g.
// libjpeg or libpng). Pixels outside of the frame's rect will remain this
// background color after drawing this frame. For incomplete decodes, pixels
// inside that rect may be (at least temporarily) set to that background color.
// In an incremental decode, later passes may then overwrite that background
// color.
//
// Determining kNoFrame or otherwise involves testing a number of conditions
// sequentially. The first satisfied condition results in setting the required
// frame to kNoFrame (an "INDx" condition) or to a non-negative frame number (a
// "DEPx" condition), and the function returning early. Those "INDx" and "DEPx"
// labels also map to comments in the function body.
//
//  - IND1: this frame is the first frame.
//  - IND2: this frame fills out the whole image, and it is completely opaque
//          or it overwrites (not blends with) the previous frame.
//  - IND3: all preceding frames' disposals are kRestorePrevious.
//  - IND4: the prevFrame's disposal is kRestoreBGColor, and it fills out the
//          whole image or it is itself otherwise independent.
//  - DEP5: this frame reports alpha (it is not completely opaque) and it
//          blends with (not overwrites) the previous frame.
//  - IND6: this frame's rect covers the rects of all preceding frames back to
//          and including the most recent independent frame before this frame.
//  - DEP7: unconditional.
//
// The "prevFrame" variable initially points to the previous frame (also known
// as the prior frame), but that variable may iterate further backwards over
// the course of this computation.
void SkFrameHolder::setAlphaAndRequiredFrame(SkFrame* frame) { … }

std::unique_ptr<SkStream> SkCodec::getEncodedData() const { … }
chromium/third_party/skia/src/codec/SkCodec.cpp
