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79 lines
2.1 KiB
79 lines
2.1 KiB
/* |
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* Copyright (c) 2010 Mans Rullgard <mans@mansr.com> |
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* |
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* This file is part of Libav. |
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* |
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* Libav is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* Libav is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with Libav; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#ifndef AVUTIL_INTMATH_H |
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#define AVUTIL_INTMATH_H |
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#include <stdint.h> |
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#include "config.h" |
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#include "attributes.h" |
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extern const uint32_t ff_inverse[257]; |
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#if ARCH_ARM |
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# include "arm/intmath.h" |
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#elif ARCH_X86 |
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# include "x86/intmath.h" |
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#endif |
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#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4) |
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#ifndef av_log2 |
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# define av_log2(x) (31 - __builtin_clz((x)|1)) |
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# ifndef av_log2_16bit |
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# define av_log2_16bit av_log2 |
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# endif |
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#endif /* av_log2 */ |
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#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */ |
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#ifndef FASTDIV |
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# if CONFIG_FASTDIV |
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# define FASTDIV(a,b) ((uint32_t)((((uint64_t)a) * ff_inverse[b]) >> 32)) |
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# else |
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# define FASTDIV(a,b) ((a) / (b)) |
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# endif |
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#endif /* FASTDIV */ |
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#include "common.h" |
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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 */
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