0,0 → 1,54 |
/** |
* VP5 and VP6 compatible video decoder (arith decoder) |
* |
* Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org> |
* Copyright (C) 2010 Eli Friedman |
* |
* 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 AVCODEC_X86_VP56_ARITH_H |
#define AVCODEC_X86_VP56_ARITH_H |
|
#if HAVE_INLINE_ASM && HAVE_FAST_CMOV |
#define vp56_rac_get_prob vp56_rac_get_prob |
static av_always_inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t prob) |
{ |
unsigned int code_word = vp56_rac_renorm(c); |
unsigned int high = c->high; |
unsigned int low = 1 + (((high - 1) * prob) >> 8); |
unsigned int low_shift = low << 16; |
int bit = 0; |
|
__asm__( |
"subl %4, %1 \n\t" |
"subl %3, %2 \n\t" |
"leal (%2, %3), %3 \n\t" |
"setae %b0 \n\t" |
"cmovb %4, %1 \n\t" |
"cmovb %3, %2 \n\t" |
: "+q"(bit), "+r"(high), "+r"(code_word), "+r"(low_shift) |
: "r"(low) |
); |
|
c->high = high; |
c->code_word = code_word; |
return bit; |
} |
#endif |
|
#endif /* AVCODEC_X86_VP56_ARITH_H */ |