timer.h

Linux下比较早的基于命令行的DVD播放器

// Copyright (c) 2004 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_OUTPUT_TIMER_H
#define DXR3PLAYER_OUTPUT_TIMER_H
//------------------------------------------------------------------------------

#include "types.h"

#include <cassert>

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

namespace sched {

class WaitCondition;

} /* namespace sched */

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

namespace output {

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

/**
 * Base class for timers used by the output handlers.
 */
class Timer
{
private:

    /**
     * The current PTS compensation. This value is added to any PTS
     * arriving on the input.
     */
    ptsdiff_t ptsCompensation;

protected:
    /**
     * Construct the timer.
     */
    Timer();

public:
    /**
     * Virtual destructor.
     */
    virtual ~Timer() {}

    /**
     * Reset the timer.
     */
    virtual void reset();

    /**
     * Get the current PTS compensation.
     */
    ptsdiff_t getPTSCompensation() const;

    /**
     * Advance the PTS compensation. 
     *
     * @param diff the advancement. It most not be negative.
     */
    void advancePTSCompensation(ptsdiff_t diff);

    /**
     * Adjust the frequency if the given PTS is the correct value.
     * This default implementation does nothing but display a warning message.
     */
    virtual void adjustFrequency(pts_t shouldBeSCR);
    
    /**
     * Get the current SCR.
     */
    virtual pts_t getCurrentSCR() const = 0;

    /**
     * Get the time in milliseconds for the given PTS.
     */
    virtual millis_t getMillis(pts_t scr) const = 0;

    /**
     * Sleep until the given condition is fulfilled or the given PTS 
     * is reached.
     *
     * @return if the condition is fulfilled
     */
    bool waitInterruptible(sched::WaitCondition& cond, pts_t scr) const;

    /**
     * Sleep until the given PTS is reached. The sleep can be 
     * interrupted
     */
    void sleep(pts_t scr) const;

    /**
     * Sleep until the given PTS is reached. The sleep can be 
     * interrupted
     */
    void sleepInterruptible(pts_t scr) const;
};

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

inline Timer::Timer() : 
    ptsCompensation(0)
{
}

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

inline ptsdiff_t Timer::getPTSCompensation() const
{
    return ptsCompensation;
}

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

inline void Timer::advancePTSCompensation(ptsdiff_t diff)
{
    assert(diff>=0);
    ptsCompensation += diff;
}

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

} /* namespace output */

//------------------------------------------------------------------------------
#endif // DXR3PLAYER_OUTPUT_TIMER_H

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