mirror of https://git.ffmpeg.org/ffmpeg.git
177 lines
9.5 KiB
C
177 lines
9.5 KiB
C
/*
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* H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
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* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* Context Adaptive Binary Arithmetic Coder.
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*/
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#include <string.h>
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#include "libavutil/common.h"
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#include "get_bits.h"
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#include "cabac.h"
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#include "cabac_functions.h"
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const uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63] = {
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9,8,7,7,6,6,6,6,5,5,5,5,5,5,5,5,
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4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
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3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
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3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
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2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
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2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
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2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
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2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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// LPS range
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-128, -128, -128, -128, -128, -128, 123, 123,
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116, 116, 111, 111, 105, 105, 100, 100,
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95, 95, 90, 90, 85, 85, 81, 81,
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77, 77, 73, 73, 69, 69, 66, 66,
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62, 62, 59, 59, 56, 56, 53, 53,
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51, 51, 48, 48, 46, 46, 43, 43,
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41, 41, 39, 39, 37, 37, 35, 35,
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33, 33, 32, 32, 30, 30, 29, 29,
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27, 27, 26, 26, 24, 24, 23, 23,
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22, 22, 21, 21, 20, 20, 19, 19,
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18, 18, 17, 17, 16, 16, 15, 15,
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14, 14, 14, 14, 13, 13, 12, 12,
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12, 12, 11, 11, 11, 11, 10, 10,
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10, 10, 9, 9, 9, 9, 8, 8,
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8, 8, 7, 7, 7, 7, 7, 7,
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6, 6, 6, 6, 6, 6, 2, 2,
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-80, -80, -89, -89, -98, -98, -106, -106,
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-114, -114, -121, -121, -128, -128, 122, 122,
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116, 116, 110, 110, 104, 104, 99, 99,
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94, 94, 89, 89, 85, 85, 80, 80,
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76, 76, 72, 72, 69, 69, 65, 65,
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62, 62, 59, 59, 56, 56, 53, 53,
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50, 50, 48, 48, 45, 45, 43, 43,
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41, 41, 39, 39, 37, 37, 35, 35,
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33, 33, 31, 31, 30, 30, 28, 28,
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27, 27, 26, 26, 24, 24, 23, 23,
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22, 22, 21, 21, 20, 20, 19, 19,
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18, 18, 17, 17, 16, 16, 15, 15,
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14, 14, 14, 14, 13, 13, 12, 12,
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12, 12, 11, 11, 11, 11, 10, 10,
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9, 9, 9, 9, 9, 9, 8, 8,
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8, 8, 7, 7, 7, 7, 2, 2,
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-48, -48, -59, -59, -69, -69, -78, -78,
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-87, -87, -96, -96, -104, -104, -112, -112,
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-119, -119, -126, -126, 123, 123, 117, 117,
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111, 111, 105, 105, 100, 100, 95, 95,
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90, 90, 86, 86, 81, 81, 77, 77,
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73, 73, 69, 69, 66, 66, 63, 63,
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59, 59, 56, 56, 54, 54, 51, 51,
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48, 48, 46, 46, 43, 43, 41, 41,
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39, 39, 37, 37, 35, 35, 33, 33,
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32, 32, 30, 30, 29, 29, 27, 27,
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26, 26, 25, 25, 23, 23, 22, 22,
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21, 21, 20, 20, 19, 19, 18, 18,
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17, 17, 16, 16, 15, 15, 15, 15,
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14, 14, 13, 13, 12, 12, 12, 12,
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11, 11, 11, 11, 10, 10, 10, 10,
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9, 9, 9, 9, 8, 8, 2, 2,
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-16, -16, -29, -29, -40, -40, -51, -51,
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-61, -61, -71, -71, -81, -81, -90, -90,
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-98, -98, -106, -106, -114, -114, -121, -121,
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-128, -128, 122, 122, 116, 116, 110, 110,
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104, 104, 99, 99, 94, 94, 89, 89,
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85, 85, 80, 80, 76, 76, 72, 72,
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69, 69, 65, 65, 62, 62, 59, 59,
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56, 56, 53, 53, 50, 50, 48, 48,
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45, 45, 43, 43, 41, 41, 39, 39,
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37, 37, 35, 35, 33, 33, 31, 31,
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30, 30, 28, 28, 27, 27, 25, 25,
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24, 24, 23, 23, 22, 22, 21, 21,
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20, 20, 19, 19, 18, 18, 17, 17,
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16, 16, 15, 15, 14, 14, 14, 14,
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13, 13, 12, 12, 12, 12, 11, 11,
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11, 11, 10, 10, 9, 9, 2, 2,
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// mlps state
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127, 126, 77, 76, 77, 76, 75, 74,
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75, 74, 75, 74, 73, 72, 73, 72,
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73, 72, 71, 70, 71, 70, 71, 70,
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69, 68, 69, 68, 67, 66, 67, 66,
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67, 66, 65, 64, 65, 64, 63, 62,
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61, 60, 61, 60, 61, 60, 59, 58,
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59, 58, 57, 56, 55, 54, 55, 54,
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53, 52, 53, 52, 51, 50, 49, 48,
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49, 48, 47, 46, 45, 44, 45, 44,
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43, 42, 43, 42, 39, 38, 39, 38,
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37, 36, 37, 36, 33, 32, 33, 32,
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31, 30, 31, 30, 27, 26, 27, 26,
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25, 24, 23, 22, 23, 22, 19, 18,
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19, 18, 17, 16, 15, 14, 13, 12,
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11, 10, 9, 8, 9, 8, 5, 4,
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5, 4, 3, 2, 1, 0, 0, 1,
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2, 3, 4, 5, 6, 7, 8, 9,
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10, 11, 12, 13, 14, 15, 16, 17,
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18, 19, 20, 21, 22, 23, 24, 25,
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26, 27, 28, 29, 30, 31, 32, 33,
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34, 35, 36, 37, 38, 39, 40, 41,
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42, 43, 44, 45, 46, 47, 48, 49,
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50, 51, 52, 53, 54, 55, 56, 57,
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58, 59, 60, 61, 62, 63, 64, 65,
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66, 67, 68, 69, 70, 71, 72, 73,
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74, 75, 76, 77, 78, 79, 80, 81,
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82, 83, 84, 85, 86, 87, 88, 89,
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90, 91, 92, 93, 94, 95, 96, 97,
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98, 99, 100, 101, 102, 103, 104, 105,
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106, 107, 108, 109, 110, 111, 112, 113,
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114, 115, 116, 117, 118, 119, 120, 121,
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122, 123, 124, 125, 124, 125, 126, 127,
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// last_coeff_flag_offset_8x8
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0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
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3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
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5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8
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};
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/**
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* @param buf_size size of buf in bits
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*/
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void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){
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c->bytestream_start=
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c->bytestream= buf;
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c->bytestream_end= buf + buf_size;
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#if CABAC_BITS == 16
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c->low = (*c->bytestream++)<<18;
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c->low+= (*c->bytestream++)<<10;
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#else
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c->low = (*c->bytestream++)<<10;
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#endif
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c->low+= ((*c->bytestream++)<<2) + 2;
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c->range= 0x1FE;
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}
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