mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
66 lines
1.8 KiB
66 lines
1.8 KiB
/* |
|
* Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org> |
|
* |
|
* 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 |
|
*/ |
|
|
|
/** |
|
* @file |
|
* Range decoder functions common to VP8 and VP9 |
|
*/ |
|
|
|
#ifndef AVCODEC_VP89_RAC_H |
|
#define AVCODEC_VP89_RAC_H |
|
|
|
#include <stdint.h> |
|
|
|
#include "libavutil/attributes.h" |
|
|
|
#include "vpx_rac.h" |
|
|
|
// rounding is different than vpx_rac_get, is vpx_rac_get wrong? |
|
static av_always_inline int vp89_rac_get(VPXRangeCoder *c) |
|
{ |
|
return vpx_rac_get_prob(c, 128); |
|
} |
|
|
|
static av_unused int vp89_rac_get_uint(VPXRangeCoder *c, int bits) |
|
{ |
|
int value = 0; |
|
|
|
while (bits--) { |
|
value = (value << 1) | vp89_rac_get(c); |
|
} |
|
|
|
return value; |
|
} |
|
|
|
// how probabilities are associated with decisions is different I think |
|
// well, the new scheme fits in the old but this way has one fewer branches per decision |
|
static av_always_inline int vp89_rac_get_tree(VPXRangeCoder *c, const int8_t (*tree)[2], |
|
const uint8_t *probs) |
|
{ |
|
int i = 0; |
|
|
|
do { |
|
i = tree[i][vpx_rac_get_prob(c, probs[i])]; |
|
} while (i > 0); |
|
|
|
return -i; |
|
} |
|
|
|
#endif /* AVCODEC_VP89_RAC_H */
|
|
|