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libavcodec
mathops.h
Go to the documentation of this file.
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/*
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* simple math operations
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* Copyright (c) 2001, 2002 Fabrice Bellard
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* Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> et al
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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 AVCODEC_MATHOPS_H
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#define AVCODEC_MATHOPS_H
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#include <stdint.h>
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#include "
libavutil/common.h
"
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#include "config.h"
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extern
const
uint32_t
ff_inverse
[257];
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extern
const
uint8_t
ff_reverse
[256];
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extern
const
uint8_t
ff_sqrt_tab
[256];
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#if ARCH_ARM
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# include "
arm/mathops.h
"
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#elif ARCH_AVR32
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# include "
avr32/mathops.h
"
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#elif ARCH_BFIN
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# include "
bfin/mathops.h
"
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#elif ARCH_MIPS
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# include "
mips/mathops.h
"
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#elif ARCH_PPC
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# include "
ppc/mathops.h
"
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#elif ARCH_X86
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# include "
x86/mathops.h
"
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#endif
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/* generic implementation */
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#ifndef MUL64
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# define MUL64(a,b) ((int64_t)(a) * (int64_t)(b))
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#endif
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#ifndef MULL
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# define MULL(a,b,s) (MUL64(a, b) >> (s))
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#endif
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#ifndef MULH
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static
av_always_inline
int
MULH
(
int
a
,
int
b
){
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return
MUL64
(a, b) >> 32;
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}
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#endif
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#ifndef UMULH
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static
av_always_inline
unsigned
UMULH
(
unsigned
a
,
unsigned
b
){
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return
((uint64_t)(a) * (uint64_t)(b))>>32;
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}
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#endif
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#ifndef MAC64
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# define MAC64(d, a, b) ((d) += MUL64(a, b))
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#endif
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#ifndef MLS64
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# define MLS64(d, a, b) ((d) -= MUL64(a, b))
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#endif
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/* signed 16x16 -> 32 multiply add accumulate */
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#ifndef MAC16
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# define MAC16(rt, ra, rb) rt += (ra) * (rb)
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#endif
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/* signed 16x16 -> 32 multiply */
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#ifndef MUL16
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# define MUL16(ra, rb) ((ra) * (rb))
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#endif
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#ifndef MLS16
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# define MLS16(rt, ra, rb) ((rt) -= (ra) * (rb))
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#endif
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/* median of 3 */
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#ifndef mid_pred
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#define mid_pred mid_pred
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static
inline
av_const
int
mid_pred
(
int
a
,
int
b
,
int
c
)
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{
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#if 0
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int
t
= (a-
b
)&((a-b)>>31);
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a-=
t
;
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b+=
t
;
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b-= (b-
c
)&((b-c)>>31);
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b+= (a-
b
)&((a-b)>>31);
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return
b
;
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#else
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if
(a>b){
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if
(c>b){
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if
(c>a) b=
a
;
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else
b=
c
;
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}
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}
else
{
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if
(b>c){
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if
(c>a) b=
c
;
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else
b=
a
;
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}
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}
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return
b
;
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#endif
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}
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#endif
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#ifndef sign_extend
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static
inline
av_const
int
sign_extend
(
int
val
,
unsigned
bits
)
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{
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unsigned
shift
= 8 *
sizeof
(int) - bits;
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union
{
unsigned
u
;
int
s
; }
v
= { (unsigned) val << shift };
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return
v
.s >>
shift
;
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}
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#endif
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#ifndef zero_extend
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static
inline
av_const
unsigned
zero_extend
(
unsigned
val,
unsigned
bits)
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{
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return
(val << ((8 *
sizeof
(
int
)) - bits)) >> ((8 *
sizeof
(int)) -
bits
);
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}
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#endif
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#ifndef COPY3_IF_LT
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#define COPY3_IF_LT(x, y, a, b, c, d)\
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if ((y) < (x)) {\
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(x) = (y);\
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(a) = (b);\
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(c) = (d);\
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}
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#endif
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#ifndef MASK_ABS
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#define MASK_ABS(mask, level) do { \
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mask = level >> 31; \
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level = (level ^ mask) - mask; \
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} while (0)
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#endif
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#ifndef NEG_SSR32
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# define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
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#endif
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#ifndef NEG_USR32
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# define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
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#endif
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#if HAVE_BIGENDIAN
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# ifndef PACK_2U8
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# define PACK_2U8(a,b) (((a) << 8) | (b))
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# endif
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# ifndef PACK_4U8
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# define PACK_4U8(a,b,c,d) (((a) << 24) | ((b) << 16) | ((c) << 8) | (d))
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# endif
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# ifndef PACK_2U16
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# define PACK_2U16(a,b) (((a) << 16) | (b))
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# endif
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#else
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# ifndef PACK_2U8
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# define PACK_2U8(a,b) (((b) << 8) | (a))
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# endif
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# ifndef PACK_4U2
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# define PACK_4U8(a,b,c,d) (((d) << 24) | ((c) << 16) | ((b) << 8) | (a))
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# endif
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# ifndef PACK_2U16
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# define PACK_2U16(a,b) (((b) << 16) | (a))
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# endif
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#endif
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#ifndef PACK_2S8
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# define PACK_2S8(a,b) PACK_2U8((a)&255, (b)&255)
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#endif
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#ifndef PACK_4S8
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# define PACK_4S8(a,b,c,d) PACK_4U8((a)&255, (b)&255, (c)&255, (d)&255)
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#endif
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#ifndef PACK_2S16
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# define PACK_2S16(a,b) PACK_2U16((a)&0xffff, (b)&0xffff)
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#endif
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#ifndef FASTDIV
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# define FASTDIV(a,b) ((uint32_t)((((uint64_t)a) * ff_inverse[b]) >> 32))
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#endif
/* FASTDIV */
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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
/* AVCODEC_MATHOPS_H */
Generated on Wed Jul 10 2013 23:47:55 for FFmpeg by
1.8.2