GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/cabac.c Lines: 19 20 95.0 %
Date: 2020-07-11 02:49:52 Branches: 3 4 75.0 %

Line Branch Exec Source
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/*
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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 FFmpeg.
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 *
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 * FFmpeg 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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 * FFmpeg 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 FFmpeg; 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 "cabac.h"
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#include "cabac_functions.h"
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DECLARE_ASM_ALIGNED(1, 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,
123
    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_encoder(CABACContext *c, uint8_t *buf, int buf_size){
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    init_put_bits(&c->pb, buf, buf_size);
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    c->low= 0;
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    c->range= 0x1FE;
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    c->outstanding_count= 0;
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    c->pb.bit_left++; //avoids firstBitFlag
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}
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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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71223
int ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size){
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71223
    c->bytestream_start=
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71223
    c->bytestream= buf;
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71223
    c->bytestream_end= buf + buf_size;
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#if CABAC_BITS == 16
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71223
    c->low =  (*c->bytestream++)<<18;
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71223
    c->low+=  (*c->bytestream++)<<10;
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    // Keep our fetches on a 2-byte boundary as this should avoid ever having to
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    // do unaligned loads if the compiler (or asm) optimises the double byte
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    // load into a single instruction
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71223
    if(((uintptr_t)c->bytestream & 1) == 0) {
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36289
        c->low += (1 << 9);
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    }
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    else {
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34934
        c->low += ((*c->bytestream++) << 2) + 2;
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    }
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#else
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    c->low =  (*c->bytestream++)<<10;
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    c->low+= ((*c->bytestream++)<<2) + 2;
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#endif
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71223
    c->range= 0x1FE;
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71223
    if ((c->range<<(CABAC_BITS+1)) < c->low)
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        return AVERROR_INVALIDDATA;
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71223
    return 0;
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}