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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.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#ifndef GRAPHICS_JPEG_H
+#define GRAPHICS_JPEG_H
+
+#include "common/stream.h"
+#include "graphics/surface.h"
+
+namespace Graphics {
+
+#define JPEG_MAX_QUANT_TABLES 4
+#define JPEG_MAX_HUFF_TABLES 2
+
+class JPEG {
+public:
+ JPEG();
+ ~JPEG();
+
+ bool read(Common::SeekableReadStream *str);
+ Surface *getComponent(uint c);
+
+private:
+ void reset();
+
+ Common::SeekableReadStream *_str;
+ uint16 _w, _h;
+
+ // Image components
+ uint8 _numComp;
+ struct Component {
+ // Global values
+ uint8 id;
+ uint8 factorH;
+ uint8 factorV;
+ uint8 quantTableSelector;
+
+ // Scan specific values
+ uint8 DCentropyTableSelector;
+ uint8 ACentropyTableSelector;
+ int16 DCpredictor;
+
+ // Result image for this component
+ Surface surface;
+ } *_components;
+
+ // Scan components
+ uint8 _numScanComp;
+ Component **_scanComp;
+ Component *_currentComp;
+
+ // Maximum sampling factors, used to calculate the interleaving of the MCU
+ uint8 _maxFactorV;
+ uint8 _maxFactorH;
+
+ // Zig-Zag order
+ static uint8 _zigZagOrder[64];
+
+ // Quantization tables
+ uint16 *_quant[JPEG_MAX_QUANT_TABLES];
+
+ // Huffman tables
+ struct HuffmanTable {
+ uint8 count;
+ uint8 *values;
+ uint8 *sizes;
+ uint16 *codes;
+ } _huff[2 * JPEG_MAX_HUFF_TABLES];
+
+ // Marker read functions
+ bool readJFIF();
+ bool readSOF0();
+ bool readDHT();
+ bool readSOS();
+ bool readDQT();
+
+ // Helper functions
+ bool readMCU(uint16 xMCU, uint16 yMCU);
+ bool readDataUnit(uint16 x, uint16 y);
+ int16 readDC();
+ void readAC(int16 *out);
+ int16 readSignedBits(uint8 numBits);
+
+ // Huffman decoding
+ uint8 readHuff(uint8 table);
+ uint8 readBit();
+ uint8 _bitsData;
+ uint8 _bitsNumber;
+
+ // Discrete Cosine Transformation
+ float idct(int x, int y, int weight, int fx, int fy);
+};
+
+} // End of Graphics namespace
+
+#endif // GRAPHICS_JPEG_H