truemotion1.h

/* 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/>.
 *
 */

// Based on the TrueMotion 1 decoder by Alex Beregszaszi & Mike Melanson in FFmpeg

#ifndef IMAGE_CODECS_TRUEMOTION1_H
#define IMAGE_CODECS_TRUEMOTION1_H

#include "image/codecs/codec.h"

namespace Image {

class TrueMotion1Decoder : public Codec {
public:
    TrueMotion1Decoder();
    ~TrueMotion1Decoder() override;

    const Graphics::Surface *decodeFrame(Common::SeekableReadStream &stream) override;

    // Always return RGB565
    Graphics::PixelFormat getPixelFormat() const override { return Graphics::PixelFormat(2, 5, 6, 5, 0, 11, 5, 0, 0); }

private:
    Graphics::Surface *_surface;

    int _mbChangeBitsRowSize;
    byte *_buf, *_mbChangeBits, *_indexStream;
    int _indexStreamSize;

    int _flags;

    struct PredictorTableEntry {
        uint32 color;
        bool getNextIndex;
    };

    PredictorTableEntry _yPredictorTable[1024];
    PredictorTableEntry _cPredictorTable[1024];

    int _blockType;
    int _blockWidth;
    int _blockHeight;

    int16 _ydt[8];
    int16 _cdt[8];

    int _lastDeltaset, _lastVectable;

    uint32 *_vertPred;

    struct {
        byte headerSize;
        byte compression;
        byte deltaset;
        byte vectable;
        uint16 ysize;
        uint16 xsize;
        uint16 checksum;
        byte version;
        byte headerType;
        byte flags;
        byte control;
        uint16 xoffset;
        uint16 yoffset;
        uint16 width;
        uint16 height;
    } _header;

    void selectDeltaTables(int deltaTableIndex);
    void decodeHeader(Common::SeekableReadStream &stream);
    void decode16();
    int makeYdt16Entry(int p1, int p2);
    int makeCdt16Entry(int p1, int p2);
    void genVectorTable16(const byte *selVectorTable);
};

} // End of namespace Image

#endif // IMAGE_CODECS_TRUEMOTION1_H