Function ff_sqrt

libavcodec/mathops.h:221–236

#ifndef ff_sqrt
#define ff_sqrt ff_sqrt
static inline av_const unsigned int ff_sqrt(unsigned int a)
{
    unsigned int b;

    if (a < 255) return (ff_sqrt_tab[a + 1] - 1) >> 4;
    else if (a < (1 << 12)) b = ff_sqrt_tab[a >> 4] >> 2;
#if !CONFIG_SMALL
    else if (a < (1 << 14)) b = ff_sqrt_tab[a >> 6] >> 1;
    else if (a < (1 << 16)) b = ff_sqrt_tab[a >> 8]   ;
#endif
    else {
        int s = av_log2_16bit(a >> 16) >> 1;
        unsigned int c = a >> (s + 2);
        b = ff_sqrt_tab[c >> (s + 8)];
        b = FASTDIV(c,b) + (b << s);
    }

    return b - (a < b * b);
}