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Diffstat (limited to 'chromium/ui/gfx/codec/jpeg_codec.h')
-rw-r--r-- | chromium/ui/gfx/codec/jpeg_codec.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/chromium/ui/gfx/codec/jpeg_codec.h b/chromium/ui/gfx/codec/jpeg_codec.h new file mode 100644 index 00000000000..e4edeee2236 --- /dev/null +++ b/chromium/ui/gfx/codec/jpeg_codec.h @@ -0,0 +1,79 @@ +// 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 <vector> + +#include "ui/base/ui_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 UI_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. It is up to the caller + // to delete the returned bitmap. + static SkBitmap* Decode(const unsigned char* input, size_t input_size); +}; + +} // namespace gfx + +#endif // UI_GFX_CODEC_JPEG_CODEC_H_ |