rlf_decoder.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/>.
 *
 */

#ifndef ZVISION_RLF_DECODER_H
#define ZVISION_RLF_DECODER_H

#include "common/file.h"
#include "video/video_decoder.h"

#include "graphics/surface.h"

namespace ZVision {

class RLFDecoder : public Video::VideoDecoder {
public:
    RLFDecoder() {}
    ~RLFDecoder() override;

    bool loadStream(Common::SeekableReadStream *stream) override;

private:
    class RLFVideoTrack : public FixedRateVideoTrack {
    public:
        RLFVideoTrack(Common::SeekableReadStream *stream);
        ~RLFVideoTrack() override;

        uint16 getWidth() const override { return _width; }
        uint16 getHeight() const override { return _height; }
        Graphics::PixelFormat getPixelFormat() const override { return Graphics::PixelFormat(2, 5, 5, 5, 0, 10, 5, 0, 0); /* RGB 555 */ }
        int getCurFrame() const override { return _displayedFrame; }
        int getFrameCount() const override { return _frameCount; }
        const Graphics::Surface *decodeNextFrame() override;
        bool isSeekable() const override { return true; }
        bool seek(const Audio::Timestamp &time) override;

    protected:
        Common::Rational getFrameRate() const override { return Common::Rational(1000, _frameTime); }

    private:
        enum EncodingType {
            Masked,
            Simple
        };

        struct Frame {
            EncodingType type;
            int8 *encodedData;
            uint32 encodedSize;
        };

        bool readHeader();

        Frame readNextFrame();

        void applyFrameToCurrent(uint frameNumber);

        void decodeMaskedRunLengthEncoding(int8 *source, int8 *dest, uint32 sourceSize, uint32 destSize) const;
        void decodeSimpleRunLengthEncoding(int8 *source, int8 *dest, uint32 sourceSize, uint32 destSize) const;

        uint _lastFrameRead;

        uint _frameCount;
        uint _width;
        uint _height;
        uint32 _frameTime; // In milliseconds
        Frame *_frames;
        Common::Array<uint> _completeFrames;

        int _displayedFrame;
        Graphics::Surface _currentFrameBuffer;
        uint32 _frameBufferByteSize;

        Common::SeekableReadStream *_readStream;
    };  // RLFVideoTrack
};

} // End of namespace ZVision

#endif