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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#ifndef IMAGE_CODECS_CODEC_H
#define IMAGE_CODECS_CODEC_H
#include "graphics/surface.h"
#include "graphics/pixelformat.h"
namespace Common {
class SeekableReadStream;
}
namespace Image {
/**
* An abstract representation of a image codec.
*
* Unlike ImageDecoder, the entire info for a frame may not be present
* within the stream. The codec may rely on the supporting container
* for parameters and can also rely on a previous (or future) frame.
* When decoding, the previous frame may not destroyed and could be
* maintained for use in the next one.
*
* An ImageDecoder can always be a Codec, but a Codec may not necessarily
* be able to be an ImageDecoder.
*
* Used in image:
* - BitmapDecoder
* - PICTDecoder
*
* Used in video:
* - AVIDecoder
* - QuickTimeDecoder
* - VMDDecoder
*/
class Codec {
public:
Codec() {}
virtual ~Codec() {}
/**
* A type of dithering.
*/
enum DitherType {
/** Unknown */
kDitherTypeUnknown,
/** Video for Windows dithering */
kDitherTypeVFW,
/** QuickTime dithering */
kDitherTypeQT
};
/**
* Decode the frame for the given data and return a pointer to a surface
* containing the decoded frame.
*
* @return a pointer to the decoded frame
*/
virtual const Graphics::Surface *decodeFrame(Common::SeekableReadStream &stream) = 0;
/**
* Get the format that the surface returned from decodeImage() will
* be in.
*/
virtual Graphics::PixelFormat getPixelFormat() const = 0;
/**
* Can this codec's frames contain a palette?
*/
virtual bool containsPalette() const { return false; }
/**
* Get the palette last decoded from decodeImage
*/
virtual const byte *getPalette() { return 0; }
/**
* Does the codec have a dirty palette?
*/
virtual bool hasDirtyPalette() const { return false; }
/**
* Can the codec dither down to 8bpp?
*/
virtual bool canDither(DitherType type) const { return false; }
/**
* Activate dithering mode with a palette
*/
virtual void setDither(DitherType type, const byte *palette) {}
/**
* Create a dither table, as used by QuickTime codecs.
*/
static byte *createQuickTimeDitherTable(const byte *palette, uint colorCount);
};
/**
* Create a codec given a bitmap/AVI compression tag.
*/
Codec *createBitmapCodec(uint32 tag, int width, int height, int bitsPerPixel);
/**
* Create a codec given a QuickTime compression tag.
*/
Codec *createQuickTimeCodec(uint32 tag, int width, int height, int bitsPerPixel);
} // End of namespace Image
#endif
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