| 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 |
| 29 | static av_always_inline int vp56_rac_get_prob(VP56RangeCoder *c, uint8_t 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 */ |