1 /* ScummVM - Graphic Adventure Engine 2 * 3 * ScummVM is the legal property of its developers, whose names 4 * are too numerous to list here. Please refer to the COPYRIGHT 5 * file distributed with this source distribution. 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 2 10 * of the License, or (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 20 * 21 */ 22 23 #ifndef IMAGE_CODECS_XAN_H 24 #define IMAGE_CODECS_XAN_H 25 26 #include "image/codecs/codec.h" 27 28 namespace Image { 29 30 /** 31 * Xan image decoder. (fourcc Xxan) 32 * 33 * Used by Crusader: No Regret AVI files 34 * 35 * This code was created based on the multimedia wiki: 36 * https://wiki.multimedia.cx/index.php/Origin_Xan_Codec 37 * and ffmpeg's libavcodec/xxan.c. 38 * The ffmpeg code is LGPL2 licensed and Copyright (C) 2011 39 * Konstantin Shishkov based on work by Mike Melanson. 40 * 41 * A similar format is used in Wing Commander III (although not in an AVI 42 * container) and IV. 43 */ 44 class XanDecoder : public Codec { 45 public: 46 XanDecoder (int width, int height, int bitsPerPixel); 47 ~XanDecoder(); 48 49 const Graphics::Surface *decodeFrame(Common::SeekableReadStream &stream) override; 50 Graphics::PixelFormat getPixelFormat() const override; 51 52 private: 53 void decodeFrameType0(Common::SeekableReadStream &stream); 54 void decodeFrameType1(Common::SeekableReadStream &stream); 55 56 /** Decompress the huffman table for base luma data */ 57 void decompressLuma(Common::SeekableReadStream &stream); 58 59 bool decodeChroma(Common::SeekableReadStream &stream, int chroma_off); 60 61 /** convert the internally expanded YUV to the output RGBA surface */ 62 void convertYUVtoRGBSurface(); 63 64 /** A buffer to hold the final frame in RGBA */ 65 Graphics::Surface _surface; 66 67 /** Dest surface width and height */ 68 int _width, _height; 69 70 /** If true, decode chroma vals in Wing Commander 4 style (false = No Regret style) */ 71 bool _wc4Mode; 72 73 /** A buffer to hold scratch data. Either chroma data in progress, or 74 * decompressed delta luma values (5-bit). Interpretation depends on frame type. */ 75 uint8 *_scratchbuf; 76 /** A buffer to hold expanded/interpolated absolute luma values (6-bit) from the values in _scratchbuf. 77 * These still need to be multiplied out to make 8-bit values. */ 78 uint8 *_lumabuf; 79 /** a buffer for uncompressed and multiplied out "y" values (of yuv) */ 80 uint8 *_ybuf; 81 /** a buffer for uncompressed "u" values (of yuv) */ 82 uint8 *_ubuf; 83 /** a buffer for uncompressed "v" values (of yuv) */ 84 uint8 *_vbuf; 85 }; 86 87 } // End of namespace Image 88 89 #endif 90