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Diffstat (limited to 'libavcodec/x86/vp56_arith.h')
-rw-r--r-- | libavcodec/x86/vp56_arith.h | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/libavcodec/x86/vp56_arith.h b/libavcodec/x86/vp56_arith.h new file mode 100644 index 0000000000..d05dcb6ed5 --- /dev/null +++ b/libavcodec/x86/vp56_arith.h @@ -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_FAST_CMOV +#define vp56_rac_get_prob vp56_rac_get_prob +static 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 << 8; + 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 */ |