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181 lines
3.4 KiB
181 lines
3.4 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 FFmpeg. |
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* |
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* FFmpeg 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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* FFmpeg 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 FFmpeg; 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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#if ARCH_ARM |
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# include "arm/intmath.h" |
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#endif |
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#if ARCH_X86 |
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# include "x86/intmath.h" |
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#endif |
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/** |
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* @addtogroup lavu_internal |
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* @{ |
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*/ |
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#if HAVE_FAST_CLZ |
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#if defined( __INTEL_COMPILER ) |
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#ifndef ff_log2 |
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# define ff_log2(x) (_bit_scan_reverse((x)|1)) |
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# ifndef ff_log2_16bit |
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# define ff_log2_16bit av_log2 |
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# endif |
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#endif /* ff_log2 */ |
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#elif AV_GCC_VERSION_AT_LEAST(3,4) |
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#ifndef ff_log2 |
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# define ff_log2(x) (31 - __builtin_clz((x)|1)) |
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# ifndef ff_log2_16bit |
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# define ff_log2_16bit av_log2 |
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# endif |
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#endif /* ff_log2 */ |
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#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */ |
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#endif |
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extern const uint8_t ff_log2_tab[256]; |
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#ifndef ff_log2 |
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#define ff_log2 ff_log2_c |
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#if !defined( _MSC_VER ) |
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static av_always_inline av_const int ff_log2_c(unsigned int v) |
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{ |
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int n = 0; |
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if (v & 0xffff0000) { |
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v >>= 16; |
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n += 16; |
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} |
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if (v & 0xff00) { |
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v >>= 8; |
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n += 8; |
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} |
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n += ff_log2_tab[v]; |
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return n; |
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} |
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#else |
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static av_always_inline av_const int ff_log2_c(unsigned int v) |
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{ |
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unsigned long n; |
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_BitScanReverse(&n, v|1); |
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return n; |
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} |
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#define ff_log2_16bit av_log2 |
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#endif |
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#endif |
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#ifndef ff_log2_16bit |
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#define ff_log2_16bit ff_log2_16bit_c |
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static av_always_inline av_const int ff_log2_16bit_c(unsigned int v) |
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{ |
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int n = 0; |
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if (v & 0xff00) { |
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v >>= 8; |
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n += 8; |
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} |
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n += ff_log2_tab[v]; |
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return n; |
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} |
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#endif |
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#define av_log2 ff_log2 |
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#define av_log2_16bit ff_log2_16bit |
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/** |
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* @} |
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*/ |
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/** |
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* @addtogroup lavu_math |
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* @{ |
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*/ |
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#if HAVE_FAST_CLZ |
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#if defined( __INTEL_COMPILER ) |
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#ifndef ff_ctz |
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#define ff_ctz(v) _bit_scan_forward(v) |
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#endif |
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#elif AV_GCC_VERSION_AT_LEAST(3,4) |
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#ifndef ff_ctz |
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#define ff_ctz(v) __builtin_ctz(v) |
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#endif |
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#endif |
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#endif |
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#ifndef ff_ctz |
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#define ff_ctz ff_ctz_c |
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#if !defined( _MSC_VER ) |
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static av_always_inline av_const int ff_ctz_c(int v) |
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{ |
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int c; |
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if (v & 0x1) |
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return 0; |
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c = 1; |
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if (!(v & 0xffff)) { |
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v >>= 16; |
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c += 16; |
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} |
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if (!(v & 0xff)) { |
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v >>= 8; |
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c += 8; |
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} |
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if (!(v & 0xf)) { |
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v >>= 4; |
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c += 4; |
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} |
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if (!(v & 0x3)) { |
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v >>= 2; |
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c += 2; |
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} |
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c -= v & 0x1; |
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return c; |
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} |
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#else |
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static av_always_inline av_const int ff_ctz_c( int v ) |
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{ |
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unsigned long c; |
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_BitScanForward(&c, v); |
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return c; |
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} |
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#endif |
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#endif |
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/** |
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* Trailing zero bit count. |
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* |
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* @param v input value. If v is 0, the result is undefined. |
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* @return the number of trailing 0-bits |
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*/ |
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int av_ctz(int v); |
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/** |
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* @} |
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*/ |
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#endif /* AVUTIL_INTMATH_H */
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