forked from KolibriOS/kolibrios
52 lines
1.7 KiB
C
52 lines
1.7 KiB
C
/**
|
|
* 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 && HAVE_6REGS
|
|
#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 low = 1 + (((c->high - 1) * prob) >> 8);
|
|
unsigned int low_shift = low << 16;
|
|
int bit = 0;
|
|
c->code_word = code_word;
|
|
|
|
__asm__(
|
|
"subl %4, %1 \n\t"
|
|
"subl %3, %2 \n\t"
|
|
"setae %b0 \n\t"
|
|
"cmovb %4, %1 \n\t"
|
|
"cmovb %5, %2 \n\t"
|
|
: "+q"(bit), "+&r"(c->high), "+&r"(c->code_word)
|
|
: "r"(low_shift), "r"(low), "r"(code_word)
|
|
);
|
|
|
|
return bit;
|
|
}
|
|
#endif
|
|
|
|
#endif /* AVCODEC_X86_VP56_ARITH_H */
|