GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/dirac_arith.c Lines: 24 24 100.0 %
Date: 2019-11-22 03:34:36 Branches: 9 10 90.0 %

Line Branch Exec Source
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/*
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 * Copyright (C) 2007 Marco Gerards <marco@gnu.org>
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 * Copyright (C) 2009 David Conrad
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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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 * Arithmetic decoder for Dirac
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 * @author Marco Gerards <marco@gnu.org>
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 */
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#include "dirac_arith.h"
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const uint16_t ff_dirac_prob[256] = {
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    0,    2,    5,    8,    11,   15,   20,   24,
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    29,   35,   41,   47,   53,   60,   67,   74,
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    82,   89,   97,   106,  114,  123,  132,  141,
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    150,  160,  170,  180,  190,  201,  211,  222,
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    233,  244,  256,  267,  279,  291,  303,  315,
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    327,  340,  353,  366,  379,  392,  405,  419,
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    433,  447,  461,  475,  489,  504,  518,  533,
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    548,  563,  578,  593,  609,  624,  640,  656,
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    672,  688,  705,  721,  738,  754,  771,  788,
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    805,  822,  840,  857,  875,  892,  910,  928,
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    946,  964,  983,  1001, 1020, 1038, 1057, 1076,
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    1095, 1114, 1133, 1153, 1172, 1192, 1211, 1231,
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    1251, 1271, 1291, 1311, 1332, 1352, 1373, 1393,
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    1414, 1435, 1456, 1477, 1498, 1520, 1541, 1562,
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    1584, 1606, 1628, 1649, 1671, 1694, 1716, 1738,
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    1760, 1783, 1806, 1828, 1851, 1874, 1897, 1920,
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    1935, 1942, 1949, 1955, 1961, 1968, 1974, 1980,
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    1985, 1991, 1996, 2001, 2006, 2011, 2016, 2021,
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    2025, 2029, 2033, 2037, 2040, 2044, 2047, 2050,
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    2053, 2056, 2058, 2061, 2063, 2065, 2066, 2068,
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    2069, 2070, 2071, 2072, 2072, 2072, 2072, 2072,
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    2072, 2071, 2070, 2069, 2068, 2066, 2065, 2063,
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    2060, 2058, 2055, 2052, 2049, 2045, 2042, 2038,
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    2033, 2029, 2024, 2019, 2013, 2008, 2002, 1996,
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    1989, 1982, 1975, 1968, 1960, 1952, 1943, 1934,
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    1925, 1916, 1906, 1896, 1885, 1874, 1863, 1851,
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    1839, 1827, 1814, 1800, 1786, 1772, 1757, 1742,
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    1727, 1710, 1694, 1676, 1659, 1640, 1622, 1602,
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    1582, 1561, 1540, 1518, 1495, 1471, 1447, 1422,
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    1396, 1369, 1341, 1312, 1282, 1251, 1219, 1186,
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    1151, 1114, 1077, 1037, 995,  952,  906,  857,
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    805,  750,  690,  625,  553,  471,  376,  255
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};
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const uint8_t ff_dirac_next_ctx[DIRAC_CTX_COUNT] = {
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    [CTX_ZPZN_F1]   = CTX_ZP_F2,
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    [CTX_ZPNN_F1]   = CTX_ZP_F2,
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    [CTX_ZP_F2]     = CTX_ZP_F3,
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    [CTX_ZP_F3]     = CTX_ZP_F4,
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    [CTX_ZP_F4]     = CTX_ZP_F5,
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    [CTX_ZP_F5]     = CTX_ZP_F6,
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    [CTX_ZP_F6]     = CTX_ZP_F6,
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    [CTX_NPZN_F1]   = CTX_NP_F2,
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    [CTX_NPNN_F1]   = CTX_NP_F2,
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    [CTX_NP_F2]     = CTX_NP_F3,
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    [CTX_NP_F3]     = CTX_NP_F4,
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    [CTX_NP_F4]     = CTX_NP_F5,
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    [CTX_NP_F5]     = CTX_NP_F6,
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    [CTX_NP_F6]     = CTX_NP_F6,
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    [CTX_DELTA_Q_F] = CTX_DELTA_Q_F,
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};
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int16_t ff_dirac_prob_branchless[256][2];
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av_cold void ff_dirac_init_arith_tables(void)
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{
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    int i;
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    for (i = 0; i < 256; i++) {
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        ff_dirac_prob_branchless[i][0] =  ff_dirac_prob[255-i];
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        ff_dirac_prob_branchless[i][1] = -ff_dirac_prob[i];
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    }
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}
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void ff_dirac_init_arith_decoder(DiracArith *c, GetBitContext *gb, int length)
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{
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    int i;
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    align_get_bits(gb);
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    length = FFMIN(length, get_bits_left(gb)/8);
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    c->bytestream     = gb->buffer + get_bits_count(gb)/8;
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    c->bytestream_end = c->bytestream + length;
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    skip_bits_long(gb, length*8);
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    c->low = 0;
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    for (i = 0; i < 4; i++) {
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        c->low <<= 8;
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        if (c->bytestream < c->bytestream_end)
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            c->low |= *c->bytestream++;
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        else
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            c->low |= 0xff;
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    }
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    c->counter = -16;
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    c->range   = 0xffff;
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    c->error   = 0;
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    c->overread= 0;
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    for (i = 0; i < DIRAC_CTX_COUNT; i++)
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        c->contexts[i] = 0x8000;
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}