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// Copyright 2008, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef CHROME_COMMON_JPEG_CODEC_H__
#define CHROME_COMMON_JPEG_CODEC_H__
#include <vector>
class SkBitmap;
// 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 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
};
// 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);
};
#endif // CHROME_COMMON_JPEG_CODEC_H__
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