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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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef IMAGE_CODECS_XAN_H
#define IMAGE_CODECS_XAN_H
#include "image/codecs/codec.h"
namespace Image {
/**
* Xan image decoder. (fourcc Xxan)
*
* Used by Crusader: No Regret AVI files
*
* This code was created based on the multimedia wiki:
* https://wiki.multimedia.cx/index.php/Origin_Xan_Codec
* and ffmpeg's libavcodec/xxan.c.
* The ffmpeg code is LGPL2 licensed and Copyright (C) 2011
* Konstantin Shishkov based on work by Mike Melanson.
*
* A similar format is used in Wing Commander III (although not in an AVI
* container) and IV.
*/
class XanDecoder : public Codec {
public:
XanDecoder (int width, int height, int bitsPerPixel);
~XanDecoder() override;
const Graphics::Surface *decodeFrame(Common::SeekableReadStream &stream) override;
Graphics::PixelFormat getPixelFormat() const override { return _pixelFormat; }
bool setOutputPixelFormat(const Graphics::PixelFormat &format) override { _pixelFormat = format; return true; }
private:
void decodeFrameType0(Common::SeekableReadStream &stream);
void decodeFrameType1(Common::SeekableReadStream &stream);
/** Decompress the huffman table for base luma data */
void decompressLuma(Common::SeekableReadStream &stream);
bool decodeChroma(Common::SeekableReadStream &stream, int chroma_off);
/** convert the internally expanded YUV to the output RGBA surface */
void convertYUVtoRGBSurface();
/** A buffer to hold the final frame */
Graphics::Surface *_surface;
/** Dest surface width and height */
int _width, _height;
/** Dest surface pixel format */
Graphics::PixelFormat _pixelFormat;
/** If true, decode chroma vals in Wing Commander 4 style (false = No Regret style) */
bool _wc4Mode;
/** A buffer to hold scratch data. Either chroma data in progress, or
* decompressed delta luma values (5-bit). Interpretation depends on frame type. */
uint8 *_scratchbuf;
/** A buffer to hold expanded/interpolated absolute luma values (6-bit) from the values in _scratchbuf.
* These still need to be multiplied out to make 8-bit values. */
uint8 *_lumabuf;
/** a buffer for uncompressed and multiplied out "y" values (of yuv) */
uint8 *_ybuf;
/** a buffer for uncompressed "u" values (of yuv) */
uint8 *_ubuf;
/** a buffer for uncompressed "v" values (of yuv) */
uint8 *_vbuf;
};
} // End of namespace Image
#endif
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