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https://github.com/libretro/scummvm.git
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116 lines
2.6 KiB
C++
116 lines
2.6 KiB
C++
/* ScummVM - Graphic Adventure Engine
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*
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* ScummVM is the legal property of its developers, whose names
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* are too numerous to list here. Please refer to the COPYRIGHT
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* file distributed with this source distribution.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* $URL$
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* $Id$
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*
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*/
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#ifndef GRAPHICS_JPEG_H
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#define GRAPHICS_JPEG_H
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#include "common/stream.h"
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#include "graphics/surface.h"
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namespace Graphics {
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#define JPEG_MAX_QUANT_TABLES 4
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#define JPEG_MAX_HUFF_TABLES 2
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class JPEG {
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public:
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JPEG();
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~JPEG();
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bool read(Common::SeekableReadStream *str);
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Surface *getComponent(uint c);
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private:
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void reset();
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Common::SeekableReadStream *_str;
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uint16 _w, _h;
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// Image components
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uint8 _numComp;
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struct Component {
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// Global values
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uint8 id;
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uint8 factorH;
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uint8 factorV;
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uint8 quantTableSelector;
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// Scan specific values
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uint8 DCentropyTableSelector;
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uint8 ACentropyTableSelector;
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int16 DCpredictor;
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// Result image for this component
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Surface surface;
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} *_components;
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// Scan components
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uint8 _numScanComp;
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Component **_scanComp;
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Component *_currentComp;
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// Maximum sampling factors, used to calculate the interleaving of the MCU
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uint8 _maxFactorV;
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uint8 _maxFactorH;
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// Quantization tables
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uint16 *_quant[JPEG_MAX_QUANT_TABLES];
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// Huffman tables
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struct HuffmanTable {
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uint8 count;
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uint8 *values;
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uint8 *sizes;
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uint16 *codes;
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} _huff[2 * JPEG_MAX_HUFF_TABLES];
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// Marker read functions
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bool readJFIF();
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bool readSOF0();
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bool readDHT();
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bool readSOS();
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bool readDQT();
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// Helper functions
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bool readMCU(uint16 xMCU, uint16 yMCU);
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bool readDataUnit(uint16 x, uint16 y);
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int16 readDC();
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void readAC(int16 *out);
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int16 readSignedBits(uint8 numBits);
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// Huffman decoding
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uint8 readHuff(uint8 table);
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uint8 readBit();
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uint8 _bitsData;
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uint8 _bitsNumber;
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// Discrete Cosine Transformation
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float idct(int x, int y, int weight, int fx, int fy);
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};
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} // End of Graphics namespace
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#endif // GRAPHICS_JPEG_H
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