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@@ -56,4 +56,26 @@ extern const uint32_t ff_inverse[257]; |
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#endif /* FASTDIV */ |
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extern const uint8_t ff_sqrt_tab[256]; |
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static inline av_const unsigned int ff_sqrt(unsigned int a) |
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{ |
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unsigned int b; |
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if (a < 255) return (ff_sqrt_tab[a + 1] - 1) >> 4; |
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else if (a < (1 << 12)) b = ff_sqrt_tab[a >> 4] >> 2; |
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#if !CONFIG_SMALL |
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else if (a < (1 << 14)) b = ff_sqrt_tab[a >> 6] >> 1; |
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else if (a < (1 << 16)) b = ff_sqrt_tab[a >> 8] ; |
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#endif |
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else { |
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int s = av_log2_16bit(a >> 16) >> 1; |
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unsigned int c = a >> (s + 2); |
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b = ff_sqrt_tab[c >> (s + 8)]; |
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b = FASTDIV(c,b) + (b << s); |
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} |
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return b - (a < b * b); |
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} |
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#endif /* AVUTIL_INTMATH_H */ |