sector.h

Linux下比较早的基于命令行的DVD播放器

//
// Copyright (c) 2003 by Istv醤 V醨adi
//
// This file is part of dxr3Player, a DVD player written specifically 
// for the DXR3 (aka Hollywood+) decoder card.

// 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

#ifndef DXR3PLAYER_DVD_DEMUX_SECTOR_H
#define DXR3PLAYER_DVD_DEMUX_SECTOR_H
//------------------------------------------------------------------------------

#include "buffer/StaticBuffer.h"
#include "buffer/WrapperBuffer.h"

//------------------------------------------------------------------------------

namespace dvd { namespace demux {

//------------------------------------------------------------------------------

const size_t SECTOR_SIZE = 2048;

//------------------------------------------------------------------------------

/**
 * The sector class (a wrapper around a sector buffer)
 */
class Sector
{
private:
    /**
     * The buffer.
     */
    StaticBuffer<SECTOR_SIZE> buffer;

public:
    /**
     * Get the pointer to the data.
     */
    const unsigned char* getData() const;

    /**
     * Get the data for writing.
     */
    unsigned char* getData();

    /**
     * Get the length of the data.
     */
    size_t getLength() const;

    /**
     * Look for the given PES header of the given length in the
     * sector. It is assumed that the first three bytes are: 0x00,
     * 0x00, 0x01.
     *
     * @param offset the offset to start the search at. Defaults to 0.
     *
     * @return the index of the first character after the header, or
     * 0, if the header is not found (since the header should have 
     * a positive length, any correct value should be positive too).
     */
    template <size_t headerLength>
    size_t findPESHeader(const unsigned char* header, size_t offset = 0) const;
};

//------------------------------------------------------------------------------

/**
 * Sector reader. It is mainly a convenience class to hide
 * WrapperBufferReader.
 */
class SectorReader : public WrapperBufferReader
{
public:
    /**
     * Construct a sector reader from the given sector.
     */
    explicit SectorReader(const Sector& sector);

    /**
     * Consturct a sector reader from the given data block. It is
     * assumed to have a length of SECTOR_SIZE.
     */
    explicit SectorReader(const unsigned char* data);
};

//------------------------------------------------------------------------------

/**
 * Sector bit reader. It is mainly a convenience class to hide
 * WrapperBufferReader.
 */
class SectorBitReader : public WrapperBufferBitReader
{
public:
    /**
     * Construct a sector bit reader from the given sector.
     */
    explicit SectorBitReader(const Sector& sector);

    /**
     * Consturct a sector bot reader from the given data block. It is
     * assumed to have a length of SECTOR_SIZE.
     */
    explicit SectorBitReader(const unsigned char* data);
};

//------------------------------------------------------------------------------
// Inline definitions
//------------------------------------------------------------------------------

inline const unsigned char* Sector::getData() const
{
    return buffer.getData();
}

//------------------------------------------------------------------------------

inline unsigned char* Sector::getData()
{
    return buffer.getData();
}

//------------------------------------------------------------------------------

inline size_t Sector::getLength() const
{
    return buffer.getLength();
}

//------------------------------------------------------------------------------

template <size_t headerLength>
inline size_t Sector::findPESHeader(const unsigned char* header, size_t offset) const
{
    const unsigned char* data = getData();

    size_t headerIndex = 0;
    size_t index = offset;

    for(; index<SECTOR_SIZE && headerIndex<headerLength; ++index) {
        if (data[index] == header[headerIndex]) {
            ++headerIndex;
        } else if (headerIndex!=2 || data[index]!=0) {
            headerIndex = 0;
        }
    }

    return (index<SECTOR_SIZE) ? index : 0;
    
}

//------------------------------------------------------------------------------
//------------------------------------------------------------------------------

inline SectorReader::SectorReader(const Sector& sector) 
{
    setData(sector.getData(), SECTOR_SIZE);
}

//------------------------------------------------------------------------------

inline SectorReader::SectorReader(const unsigned char* data)
{
    setData(data, SECTOR_SIZE);
}

//------------------------------------------------------------------------------
//------------------------------------------------------------------------------

inline SectorBitReader::SectorBitReader(const Sector& sector) 
{
    setData(sector.getData(), SECTOR_SIZE);
}

//------------------------------------------------------------------------------

inline SectorBitReader::SectorBitReader(const unsigned char* data)
{
    setData(data, SECTOR_SIZE);
}

//------------------------------------------------------------------------------

} /* namespace dvd::demux */ } /* namespace dvd */

//------------------------------------------------------------------------------
#endif // DXR3PLAYER_DVD_DEMUX_SECTOR_H

// Local variables:
// mode: c++
// End: