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/*
* Copyright 2017 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkJpegEncoder_DEFINED
#define SkJpegEncoder_DEFINED
#include "include/codec/SkEncodedOrigin.h"
#include "include/core/SkRefCnt.h"
#include "include/private/base/SkAPI.h"
#include <memory>
#include <optional>
class SkColorSpace;
class SkData;
class SkEncoder;
class SkPixmap;
class SkWStream;
class SkImage;
class GrDirectContext;
class SkYUVAPixmaps;
struct skcms_ICCProfile;
namespace SkJpegEncoder {
enum class AlphaOption {
kIgnore,
kBlendOnBlack,
};
enum class Downsample {
/**
* Reduction by a factor of two in both the horizontal and vertical directions.
*/
k420,
/**
* Reduction by a factor of two in the horizontal direction.
*/
k422,
/**
* No downsampling.
*/
k444,
};
struct Options {
/**
* |fQuality| must be in [0, 100] where 0 corresponds to the lowest quality.
*/
int fQuality = 100;
/**
* Choose the downsampling factor for the U and V components. This is only
* meaningful if the |src| is not kGray, since kGray will not be encoded as YUV.
* This is ignored in favor of |src|'s subsampling when |src| is an SkYUVAPixmaps.
*
* Our default value matches the libjpeg-turbo default.
*/
Downsample fDownsample = Downsample::k420;
/**
* Jpegs must be opaque. This instructs the encoder on how to handle input
* images with alpha.
*
* The default is to ignore the alpha channel and treat the image as opaque.
* Another option is to blend the pixels onto a black background before encoding.
* In the second case, the encoder supports linear or legacy blending.
*/
AlphaOption fAlphaOption = AlphaOption::kIgnore;
/**
* Optional XMP metadata.
*/
const SkData* xmpMetadata = nullptr;
/**
* An optional ICC profile to override the default behavior.
*
* The default behavior is to generate an ICC profile using a primary matrix and
* analytic transfer function. If the color space of |src| cannot be represented
* in this way (e.g, it is HLG or PQ), then no profile will be embedded.
*/
const skcms_ICCProfile* fICCProfile = nullptr;
const char* fICCProfileDescription = nullptr;
std::optional<SkEncodedOrigin> fOrigin;
};
/**
* Encode the |src| pixels to the |dst| stream.
* |options| may be used to control the encoding behavior.
*
* Returns true on success. Returns false on an invalid or unsupported |src|.
*/
SK_API bool Encode(SkWStream* dst, const SkPixmap& src, const Options& options);
SK_API bool Encode(SkWStream* dst,
const SkYUVAPixmaps& src,
const SkColorSpace* srcColorSpace,
const Options& options);
/**
* Encode the provided image and return the resulting bytes. If the image was created as
* a texture-backed image on a GPU context, that |ctx| must be provided so the pixels
* can be read before being encoded. For raster-backed images, |ctx| can be nullptr.
* |options| may be used to control the encoding behavior.
*
* Returns nullptr if the pixels could not be read or encoding otherwise fails.
*/
SK_API sk_sp<SkData> Encode(GrDirectContext* ctx, const SkImage* img, const Options& options);
/**
* Create a jpeg encoder that will encode the |src| pixels to the |dst| stream.
* |options| may be used to control the encoding behavior.
*
* |dst| is unowned but must remain valid for the lifetime of the object.
*
* This returns nullptr on an invalid or unsupported |src|.
*/
SK_API std::unique_ptr<SkEncoder> Make(SkWStream* dst, const SkPixmap& src, const Options& options);
SK_API std::unique_ptr<SkEncoder> Make(SkWStream* dst,
const SkYUVAPixmaps& src,
const SkColorSpace* srcColorSpace,
const Options& options);
} // namespace SkJpegEncoder
#endif
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