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vp56_arith.h
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1 /**
2  * VP5 and VP6 compatible video decoder (arith decoder)
3  *
4  * Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
5  * Copyright (C) 2010 Eli Friedman
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 #ifndef AVCODEC_X86_VP56_ARITH_H
25 #define AVCODEC_X86_VP56_ARITH_H
26 
27 #if HAVE_INLINE_ASM && HAVE_FAST_CMOV && HAVE_6REGS
28 #define vp56_rac_get_prob vp56_rac_get_prob
30 {
31  unsigned int code_word = vp56_rac_renorm(c);
32  unsigned int low = 1 + (((c->high - 1) * prob) >> 8);
33  unsigned int low_shift = low << 16;
34  int bit = 0;
35  c->code_word = code_word;
36 
37  __asm__(
38  "subl %4, %1 \n\t"
39  "subl %3, %2 \n\t"
40  "setae %b0 \n\t"
41  "cmovb %4, %1 \n\t"
42  "cmovb %5, %2 \n\t"
43  : "+q"(bit), "+&r"(c->high), "+&r"(c->code_word)
44  : "r"(low_shift), "r"(low), "r"(code_word)
45  );
46 
47  return bit;
48 }
49 #endif
50 
51 #endif /* AVCODEC_X86_VP56_ARITH_H */
unsigned int code_word
Definition: vp56.h:91
uint8_t
#define prob(name, subs,...)
Definition: cbs_vp9.c:367
#define vp56_rac_get_prob
Definition: vp56.h:254
static av_always_inline unsigned int vp56_rac_renorm(VP56RangeCoder *c)
Definition: vp56.h:230
static double c[64]
#define av_always_inline
Definition: attributes.h:39
int high
Definition: vp56.h:86