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Diffstat (limited to 'media/ffvpx/libavutil/intmath.h')
| -rw-r--r-- | media/ffvpx/libavutil/intmath.h | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/media/ffvpx/libavutil/intmath.h b/media/ffvpx/libavutil/intmath.h new file mode 100644 index 000000000..9573109e9 --- /dev/null +++ b/media/ffvpx/libavutil/intmath.h @@ -0,0 +1,165 @@ +/* + * 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" + +#if ARCH_ARM +# include "arm/intmath.h" +#endif +#if ARCH_X86 +# include "x86/intmath.h" +#endif + +#if HAVE_FAST_CLZ +#if AV_GCC_VERSION_AT_LEAST(3,4) +#ifndef ff_log2 +# define ff_log2(x) (31 - __builtin_clz((x)|1)) +# ifndef ff_log2_16bit +# define ff_log2_16bit av_log2 +# endif +#endif /* ff_log2 */ +#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */ +#endif + +extern const uint8_t ff_log2_tab[256]; + +#ifndef ff_log2 +#define ff_log2 ff_log2_c +static av_always_inline av_const int ff_log2_c(unsigned int v) +{ + int n = 0; + if (v & 0xffff0000) { + v >>= 16; + n += 16; + } + if (v & 0xff00) { + v >>= 8; + n += 8; + } + n += ff_log2_tab[v]; + + return n; +} +#endif + +#ifndef ff_log2_16bit +#define ff_log2_16bit ff_log2_16bit_c +static av_always_inline av_const int ff_log2_16bit_c(unsigned int v) +{ + int n = 0; + if (v & 0xff00) { + v >>= 8; + n += 8; + } + n += ff_log2_tab[v]; + + return n; +} +#endif + +#define av_log2 ff_log2 +#define av_log2_16bit ff_log2_16bit + +/** + * @addtogroup lavu_math + * @{ + */ + +#if HAVE_FAST_CLZ +#if AV_GCC_VERSION_AT_LEAST(3,4) +#ifndef ff_ctz +#define ff_ctz(v) __builtin_ctz(v) +#endif +#ifndef ff_ctzll +#define ff_ctzll(v) __builtin_ctzll(v) +#endif +#ifndef ff_clz +#define ff_clz(v) __builtin_clz(v) +#endif +#endif +#endif + +#ifndef ff_ctz +#define ff_ctz ff_ctz_c +/** + * Trailing zero bit count. + * + * @param v input value. If v is 0, the result is undefined. + * @return the number of trailing 0-bits + */ +/* We use the De-Bruijn method outlined in: + * http://supertech.csail.mit.edu/papers/debruijn.pdf. */ +static av_always_inline av_const int ff_ctz_c(int v) +{ + static const uint8_t debruijn_ctz32[32] = { + 0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8, + 31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9 + }; + return debruijn_ctz32[(uint32_t)((v & -v) * 0x077CB531U) >> 27]; +} +#endif + +#ifndef ff_ctzll +#define ff_ctzll ff_ctzll_c +/* We use the De-Bruijn method outlined in: + * http://supertech.csail.mit.edu/papers/debruijn.pdf. */ +static av_always_inline av_const int ff_ctzll_c(long long v) +{ + static const uint8_t debruijn_ctz64[64] = { + 0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28, + 62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11, + 63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10, + 51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12 + }; + return debruijn_ctz64[(uint64_t)((v & -v) * 0x022FDD63CC95386DU) >> 58]; +} +#endif + +#ifndef ff_clz +#define ff_clz ff_clz_c +static av_always_inline av_const unsigned ff_clz_c(unsigned x) +{ + unsigned i = sizeof(x) * 8; + + while (x) { + x >>= 1; + i--; + } + + return i; +} +#endif + +#if AV_GCC_VERSION_AT_LEAST(3,4) +#ifndef av_parity +#define av_parity __builtin_parity +#endif +#endif + +/** + * @} + */ +#endif /* AVUTIL_INTMATH_H */ |