/* * Copyright (c) 2010 Mans Rullgard <mans@mansr.com> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVUTIL_INTMATH_H #define AVUTIL_INTMATH_H #include <stdint.h> #include "config.h" #include "attributes.h" extern const uint32_t ff_inverse[257]; #if ARCH_ARM # include "arm/intmath.h" #elif ARCH_X86 # include "x86/intmath.h" #endif #if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4) #ifndef av_log2 #define av_log2(x) (31 - __builtin_clz((x)|1)) #ifndef av_log2_16bit #define av_log2_16bit av_log2 #endif #endif /* av_log2 */ #endif /* AV_GCC_VERSION_AT_LEAST(3,4) */ #ifndef FASTDIV #if CONFIG_FASTDIV # define FASTDIV(a,b) ((uint32_t)((((uint64_t)a) * ff_inverse[b]) >> 32)) #else # define FASTDIV(a,b) ((a) / (b)) #endif #endif /* FASTDIV */ /* * Get definition of av_log2_c from common.h. In the event we got * here through common.h including this file, including it again will * be a no-op due to multi-inclusion guards, so we must duplicate the * fallback defines here. */ #include "common.h" #ifndef av_log2 # define av_log2 av_log2_c #endif #ifndef av_log2_16bit # define av_log2_16bit av_log2_16bit_c #endif extern const uint8_t ff_sqrt_tab[256]; 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); } #endif /* AVUTIL_INTMATH_H */