| /* |
| * 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/encode/SkEncoder.h" |
| |
| class SkJpegEncoderMgr; |
| class SkWStream; |
| |
| class SK_API SkJpegEncoder : public SkEncoder { |
| public: |
| |
| 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. |
| * |
| * 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; |
| }; |
| |
| /** |
| * 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|. |
| */ |
| static bool Encode(SkWStream* dst, const SkPixmap& src, 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|. |
| */ |
| static std::unique_ptr<SkEncoder> Make(SkWStream* dst, const SkPixmap& src, |
| const Options& options); |
| |
| ~SkJpegEncoder() override; |
| |
| protected: |
| bool onEncodeRows(int numRows) override; |
| |
| private: |
| SkJpegEncoder(std::unique_ptr<SkJpegEncoderMgr>, const SkPixmap& src); |
| |
| std::unique_ptr<SkJpegEncoderMgr> fEncoderMgr; |
| using INHERITED = SkEncoder; |
| }; |
| |
| #endif |