| // Copyright (c) 2011 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef UI_GFX_CODEC_JPEG_CODEC_H_ |
| #define UI_GFX_CODEC_JPEG_CODEC_H_ |
| |
| #include <stddef.h> |
| |
| #include <memory> |
| #include <vector> |
| |
| #include "ui/gfx/gfx_export.h" |
| |
| class SkBitmap; |
| |
| namespace gfx { |
| |
| // Interface for encoding/decoding JPEG data. This is a wrapper around libjpeg, |
| // which has an inconvenient interface for callers. This is only used for UI |
| // elements, WebKit has its own more complicated JPEG decoder which handles, |
| // among other things, partially downloaded data. |
| class GFX_EXPORT JPEGCodec { |
| public: |
| enum ColorFormat { |
| // 3 bytes per pixel (packed), in RGB order regardless of endianness. |
| // This is the native JPEG format. |
| FORMAT_RGB, |
| |
| // 4 bytes per pixel, in RGBA order in mem regardless of endianness. |
| FORMAT_RGBA, |
| |
| // 4 bytes per pixel, in BGRA order in mem regardless of endianness. |
| // This is the default Windows DIB order. |
| FORMAT_BGRA, |
| |
| // 4 bytes per pixel, it can be either RGBA or BGRA. It depends on the bit |
| // order in kARGB_8888_Config skia bitmap. |
| FORMAT_SkBitmap |
| }; |
| |
| enum LibraryVariant { |
| SYSTEM_LIBJPEG = 0, |
| LIBJPEG_TURBO, |
| IJG_LIBJPEG, |
| }; |
| |
| // This method helps identify at run time which library chromium is using. |
| static LibraryVariant JpegLibraryVariant(); |
| |
| // Encodes the given raw 'input' data, with each pixel being represented as |
| // given in 'format'. The encoded JPEG data will be written into the supplied |
| // vector and true will be returned on success. On failure (false), the |
| // contents of the output buffer are undefined. |
| // |
| // w, h: dimensions of the image |
| // row_byte_width: the width in bytes of each row. This may be greater than |
| // w * bytes_per_pixel if there is extra padding at the end of each row |
| // (often, each row is padded to the next machine word). |
| // quality: an integer in the range 0-100, where 100 is the highest quality. |
| static bool Encode(const unsigned char* input, ColorFormat format, |
| int w, int h, int row_byte_width, |
| int quality, std::vector<unsigned char>* output); |
| |
| // Decodes the JPEG data contained in input of length input_size. The |
| // decoded data will be placed in *output with the dimensions in *w and *h |
| // on success (returns true). This data will be written in the'format' |
| // format. On failure, the values of these output variables is undefined. |
| static bool Decode(const unsigned char* input, size_t input_size, |
| ColorFormat format, std::vector<unsigned char>* output, |
| int* w, int* h); |
| |
| // Decodes the JPEG data contained in input of length input_size. If |
| // successful, a SkBitmap is created and returned. |
| static std::unique_ptr<SkBitmap> Decode(const unsigned char* input, |
| size_t input_size); |
| }; |
| |
| } // namespace gfx |
| |
| #endif // UI_GFX_CODEC_JPEG_CODEC_H_ |