| 1 | /*
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| 2 | * bit_allocate.c
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| 3 | * Copyright (C) 2000-2003 Michel Lespinasse <[email protected]>
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| 4 | * Copyright (C) 1999-2000 Aaron Holtzman <[email protected]>
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| 5 | *
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| 6 | * This file is part of a52dec, a free ATSC A-52 stream decoder.
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| 7 | * See http://liba52.sourceforge.net/ for updates.
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| 8 | *
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| 9 | * a52dec is free software; you can redistribute it and/or modify
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| 10 | * it under the terms of the GNU General Public License as published by
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| 11 | * the Free Software Foundation; either version 2 of the License, or
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| 12 | * (at your option) any later version.
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| 13 | *
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| 14 | * a52dec is distributed in the hope that it will be useful,
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| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 17 | * GNU General Public License for more details.
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| 18 | *
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| 19 | * You should have received a copy of the GNU General Public License
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| 20 | * along with this program; if not, write to the Free Software
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| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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| 22 | */
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| 23 | #include "a52.h"
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| 24 | #include "a52_internal.h"
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| 25 |
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| 26 | static int hthtab[3][50] = {
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| 27 | {0x730, 0x730, 0x7c0, 0x800, 0x820, 0x840, 0x850, 0x850, 0x860, 0x860,
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| 28 | 0x860, 0x860, 0x860, 0x870, 0x870, 0x870, 0x880, 0x880, 0x890, 0x890,
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| 29 | 0x8a0, 0x8a0, 0x8b0, 0x8b0, 0x8c0, 0x8c0, 0x8d0, 0x8e0, 0x8f0, 0x900,
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| 30 | 0x910, 0x910, 0x910, 0x910, 0x900, 0x8f0, 0x8c0, 0x870, 0x820, 0x7e0,
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| 31 | 0x7a0, 0x770, 0x760, 0x7a0, 0x7c0, 0x7c0, 0x6e0, 0x400, 0x3c0, 0x3c0},
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| 32 | {0x710, 0x710, 0x7a0, 0x7f0, 0x820, 0x830, 0x840, 0x850, 0x850, 0x860,
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| 33 | 0x860, 0x860, 0x860, 0x860, 0x870, 0x870, 0x870, 0x880, 0x880, 0x880,
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| 34 | 0x890, 0x890, 0x8a0, 0x8a0, 0x8b0, 0x8b0, 0x8c0, 0x8c0, 0x8e0, 0x8f0,
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| 35 | 0x900, 0x910, 0x910, 0x910, 0x910, 0x900, 0x8e0, 0x8b0, 0x870, 0x820,
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| 36 | 0x7e0, 0x7b0, 0x760, 0x770, 0x7a0, 0x7c0, 0x780, 0x5d0, 0x3c0, 0x3c0},
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| 37 | {0x680, 0x680, 0x750, 0x7b0, 0x7e0, 0x810, 0x820, 0x830, 0x840, 0x850,
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| 38 | 0x850, 0x850, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860,
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| 39 | 0x870, 0x870, 0x870, 0x870, 0x880, 0x880, 0x880, 0x890, 0x8a0, 0x8b0,
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| 40 | 0x8c0, 0x8d0, 0x8e0, 0x8f0, 0x900, 0x910, 0x910, 0x910, 0x900, 0x8f0,
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| 41 | 0x8d0, 0x8b0, 0x840, 0x7f0, 0x790, 0x760, 0x7a0, 0x7c0, 0x7b0, 0x720}
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| 42 | };
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| 43 |
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| 44 | static int8_t baptab[305] = {
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| 45 | 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
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| 46 | 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
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| 47 | 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
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| 48 | 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
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| 49 | 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
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| 50 | 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, /* 93 padding elems */
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| 51 |
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| 52 | 16, 16, 16, 16, 16, 16, 16, 16, 16, 14, 14, 14, 14, 14, 14, 14,
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| 53 | 14, 12, 12, 12, 12, 11, 11, 11, 11, 10, 10, 10, 10, 9, 9, 9,
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| 54 | 9, 8, 8, 8, 8, 7, 7, 7, 7, 6, 6, 6, 6, 5, 5, 5,
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| 55 | 5, 4, 4, -3, -3, 3, 3, 3, -2, -2, -1, -1, -1, -1, -1, 0,
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| 56 |
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| 57 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 58 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 59 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 60 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 61 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 62 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 63 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 64 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 65 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 66 | 0, 0, 0, 0 /* 148 padding elems */
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| 67 | };
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| 68 |
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| 69 | static int bndtab[30] = {21, 22, 23, 24, 25, 26, 27, 28, 31, 34,
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| 70 | 37, 40, 43, 46, 49, 55, 61, 67, 73, 79,
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| 71 | 85, 97, 109, 121, 133, 157, 181, 205, 229, 253};
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| 72 |
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| 73 | static int8_t latab[256] = {
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| 74 | -64, -63, -62, -61, -60, -59, -58, -57, -56, -55, -54, -53,
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| 75 | -52, -52, -51, -50, -49, -48, -47, -47, -46, -45, -44, -44,
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| 76 | -43, -42, -41, -41, -40, -39, -38, -38, -37, -36, -36, -35,
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| 77 | -35, -34, -33, -33, -32, -32, -31, -30, -30, -29, -29, -28,
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| 78 | -28, -27, -27, -26, -26, -25, -25, -24, -24, -23, -23, -22,
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| 79 | -22, -21, -21, -21, -20, -20, -19, -19, -19, -18, -18, -18,
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| 80 | -17, -17, -17, -16, -16, -16, -15, -15, -15, -14, -14, -14,
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| 81 | -13, -13, -13, -13, -12, -12, -12, -12, -11, -11, -11, -11,
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| 82 | -10, -10, -10, -10, -10, -9, -9, -9, -9, -9, -8, -8,
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| 83 | -8, -8, -8, -8, -7, -7, -7, -7, -7, -7, -6, -6,
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| 84 | -6, -6, -6, -6, -6, -6, -5, -5, -5, -5, -5, -5,
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| 85 | -5, -5, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4,
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| 86 | -4, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3,
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| 87 | -3, -3, -3, -2, -2, -2, -2, -2, -2, -2, -2, -2,
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| 88 | -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -1,
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| 89 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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| 90 | -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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| 91 | -1, -1, -1, -1, -1, -1, 0, 0, 0, 0, 0, 0,
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| 92 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 93 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 94 | 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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| 95 | 0, 0, 0, 0
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| 96 | };
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| 97 |
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| 98 | #define UPDATE_LEAK() \
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| 99 | do { \
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| 100 | fastleak += fdecay; \
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| 101 | if (fastleak > psd + fgain) \
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| 102 | fastleak = psd + fgain; \
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| 103 | slowleak += sdecay; \
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| 104 | if (slowleak > psd + sgain) \
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| 105 | slowleak = psd + sgain; \
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| 106 | } while (0)
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| 107 |
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| 108 | #define COMPUTE_MASK() \
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| 109 | do { \
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| 110 | if (psd > dbknee) \
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| 111 | mask -= (psd - dbknee) >> 2; \
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| 112 | if (mask > hth [i >> halfrate]) \
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| 113 | mask = hth [i >> halfrate]; \
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| 114 | mask -= snroffset + 128 * deltba[i]; \
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| 115 | mask = (mask > 0) ? 0 : ((-mask) >> 5); \
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| 116 | mask -= floor; \
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| 117 | } while (0)
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| 118 |
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| 119 | void a52_bit_allocate (a52_state_t * state, ba_t * ba, int bndstart,
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| 120 | int start, int end, int fastleak, int slowleak,
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| 121 | expbap_t * expbap)
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| 122 | {
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| 123 | static int slowgain[4] = {0x540, 0x4d8, 0x478, 0x410};
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| 124 | static int dbpbtab[4] = {0xc00, 0x500, 0x300, 0x100};
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| 125 | static int floortab[8] = {0x910, 0x950, 0x990, 0x9d0,
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| 126 | 0xa10, 0xa90, 0xb10, 0x1400};
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| 127 |
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| 128 | int i, j;
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| 129 | uint8_t * exp;
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| 130 | int8_t * bap;
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| 131 | int fdecay, fgain, sdecay, sgain, dbknee, floor, snroffset;
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| 132 | int psd, mask;
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| 133 | int8_t * deltba;
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| 134 | int * hth;
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| 135 | int halfrate;
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| 136 |
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| 137 | halfrate = state->halfrate;
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| 138 | fdecay = (63 + 20 * ((state->bai >> 7) & 3)) >> halfrate; /* fdcycod */
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| 139 | fgain = 128 + 128 * (ba->bai & 7); /* fgaincod */
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| 140 | sdecay = (15 + 2 * (state->bai >> 9)) >> halfrate; /* sdcycod */
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| 141 | sgain = slowgain[(state->bai >> 5) & 3]; /* sgaincod */
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| 142 | dbknee = dbpbtab[(state->bai >> 3) & 3]; /* dbpbcod */
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| 143 | hth = hthtab[state->fscod];
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| 144 | /*
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| 145 | * if there is no delta bit allocation, make deltba point to an area
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| 146 | * known to contain zeroes. baptab+156 here.
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| 147 | */
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| 148 | deltba = (ba->deltbae == DELTA_BIT_NONE) ? baptab + 156 : ba->deltba;
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| 149 | floor = floortab[state->bai & 7]; /* floorcod */
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| 150 | snroffset = 960 - 64 * state->csnroffst - 4 * (ba->bai >> 3) + floor;
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| 151 | floor >>= 5;
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| 152 |
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| 153 | exp = expbap->exp;
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| 154 | bap = expbap->bap;
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| 155 |
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| 156 | i = bndstart;
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| 157 | j = start;
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| 158 | if (start == 0) { /* not the coupling channel */
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| 159 | int lowcomp;
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| 160 |
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| 161 | lowcomp = 0;
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| 162 | j = end - 1;
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| 163 | do {
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| 164 | if (i < j) {
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| 165 | if (exp[i+1] == exp[i] - 2)
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| 166 | lowcomp = 384;
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| 167 | else if (lowcomp && (exp[i+1] > exp[i]))
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| 168 | lowcomp -= 64;
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| 169 | }
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| 170 | psd = 128 * exp[i];
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| 171 | mask = psd + fgain + lowcomp;
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| 172 | COMPUTE_MASK ();
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| 173 | bap[i] = (baptab+156)[mask + 4 * exp[i]];
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| 174 | i++;
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| 175 | } while ((i < 3) || ((i < 7) && (exp[i] > exp[i-1])));
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| 176 | fastleak = psd + fgain;
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| 177 | slowleak = psd + sgain;
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| 178 |
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| 179 | while (i < 7) {
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| 180 | if (i < j) {
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| 181 | if (exp[i+1] == exp[i] - 2)
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| 182 | lowcomp = 384;
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| 183 | else if (lowcomp && (exp[i+1] > exp[i]))
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| 184 | lowcomp -= 64;
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| 185 | }
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| 186 | psd = 128 * exp[i];
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| 187 | UPDATE_LEAK ();
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| 188 | mask = ((fastleak + lowcomp < slowleak) ?
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| 189 | fastleak + lowcomp : slowleak);
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| 190 | COMPUTE_MASK ();
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| 191 | bap[i] = (baptab+156)[mask + 4 * exp[i]];
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| 192 | i++;
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| 193 | }
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| 194 |
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| 195 | if (end == 7) /* lfe channel */
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| 196 | return;
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| 197 |
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| 198 | do {
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| 199 | if (exp[i+1] == exp[i] - 2)
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| 200 | lowcomp = 320;
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| 201 | else if (lowcomp && (exp[i+1] > exp[i]))
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| 202 | lowcomp -= 64;
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| 203 | psd = 128 * exp[i];
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| 204 | UPDATE_LEAK ();
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| 205 | mask = ((fastleak + lowcomp < slowleak) ?
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| 206 | fastleak + lowcomp : slowleak);
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| 207 | COMPUTE_MASK ();
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| 208 | bap[i] = (baptab+156)[mask + 4 * exp[i]];
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| 209 | i++;
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| 210 | } while (i < 20);
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| 211 |
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| 212 | while (lowcomp > 128) { /* two iterations maximum */
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| 213 | lowcomp -= 128;
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| 214 | psd = 128 * exp[i];
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| 215 | UPDATE_LEAK ();
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| 216 | mask = ((fastleak + lowcomp < slowleak) ?
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| 217 | fastleak + lowcomp : slowleak);
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| 218 | COMPUTE_MASK ();
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| 219 | bap[i] = (baptab+156)[mask + 4 * exp[i]];
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| 220 | i++;
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| 221 | }
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| 222 | j = i;
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| 223 | }
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| 224 |
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| 225 | do {
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| 226 | int startband, endband;
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| 227 |
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| 228 | startband = j;
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| 229 | endband = (bndtab[i-20] < end) ? bndtab[i-20] : end;
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| 230 | psd = 128 * exp[j++];
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| 231 | while (j < endband) {
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| 232 | int next, delta;
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| 233 |
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| 234 | next = 128 * exp[j++];
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| 235 | delta = next - psd;
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| 236 | switch (delta >> 9) {
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| 237 | case -6: case -5: case -4: case -3: case -2:
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| 238 | psd = next;
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| 239 | break;
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| 240 | case -1:
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| 241 | psd = next + latab[(-delta) >> 1];
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| 242 | break;
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| 243 | case 0:
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| 244 | psd += latab[delta >> 1];
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| 245 | break;
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| 246 | }
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| 247 | }
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| 248 | /* minpsd = -289 */
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| 249 | UPDATE_LEAK ();
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| 250 | mask = (fastleak < slowleak) ? fastleak : slowleak;
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| 251 | COMPUTE_MASK ();
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| 252 | i++;
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| 253 | j = startband;
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| 254 | do {
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| 255 | /* max(mask+4*exp)=147=-(minpsd+fgain-deltba-snroffset)>>5+4*exp */
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| 256 | /* min(mask+4*exp)=-156=-(sgain-deltba-snroffset)>>5 */
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| 257 | bap[j] = (baptab+156)[mask + 4 * exp[j]];
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| 258 | } while (++j < endband);
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| 259 | } while (j < end);
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| 260 | }
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