vpx_arith.h (1777B)
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_VPX_ARITH_H 25 #define AVCODEC_X86_VPX_ARITH_H 26 27 #include "libavutil/x86/asm.h" 28 29 #if HAVE_INLINE_ASM && HAVE_FAST_CMOV && HAVE_6REGS 30 #include "libavutil/attributes.h" 31 32 #define vpx_rac_get_prob vpx_rac_get_prob 33 static av_always_inline int vpx_rac_get_prob(VPXRangeCoder *c, uint8_t prob) 34 { 35 unsigned int code_word = vpx_rac_renorm(c); 36 unsigned int low = 1 + (((c->high - 1) * prob) >> 8); 37 unsigned int low_shift = low << 16; 38 int bit = 0; 39 c->code_word = code_word; 40 41 __asm__( 42 "subl %4, %1 \n\t" 43 "subl %3, %2 \n\t" 44 "setae %b0 \n\t" 45 "cmovb %4, %1 \n\t" 46 "cmovb %5, %2 \n\t" 47 : "+q"(bit), "+&r"(c->high), "+&r"(c->code_word) 48 : "r"(low_shift), "r"(low), "r"(code_word) 49 ); 50 51 return bit; 52 } 53 #endif 54 55 #endif /* AVCODEC_X86_VPX_ARITH_H */