cvauxutils.cpp.svn-base

来自「非结构化路识别」· SVN-BASE 代码 · 共 93 行

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#include "_cvaux.h"
#include <time.h>

typedef int64 (CV_CDECL * rdtsc_func)(void);

/* helper functions for RNG initialization and accurate time measurement: x86 only */
CV_IMPL  int64  cvGetTickCount( void )
{
#ifndef WIN32
    return clock();
#else
    static const char code[] = "\x0f\x31\xc3";
    rdtsc_func func = (rdtsc_func)(void*)code;
    return func();
#endif
}


CV_IMPL  double  cvGetTickFrequency()
{
#ifndef WIN32
    return CLOCKS_PER_SEC*1e-6;
#else
    int64 clocks1, clocks2;
    volatile int t;
    int dt = 100;
    int frequency = 0, old_frequency;

    do
    {
        old_frequency = frequency;
        t = clock();
        while( t==clock() );
        t = clock();

        clocks1 = cvGetTickCount();
        while( dt+t>clock() );
        clocks2 = cvGetTickCount();

        frequency = (int)(((double)(clocks2 - clocks1))/(1e3*dt)+.5) + 10;
        if( frequency % 50 <= 16 )
            frequency = (frequency/50)*50;
        else
            frequency = (frequency/100)*100 + ((frequency % 100)/33)*33;
    }
    while( frequency != old_frequency );
    return (double)frequency;
#endif
}

/* End of file. */