/* * bit_allocate.c * Copyright (C) 2000-2002 Michel Lespinasse * Copyright (C) 1999-2000 Aaron Holtzman * * This file is part of a52dec, a free ATSC A-52 stream decoder. * See http://liba52.sourceforge.net/ for updates. * * a52dec is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * a52dec 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "config.h" #include #include "a52.h" #include "a52_internal.h" static int hthtab[3][50] = { {0x730, 0x730, 0x7c0, 0x800, 0x820, 0x840, 0x850, 0x850, 0x860, 0x860, 0x860, 0x860, 0x860, 0x870, 0x870, 0x870, 0x880, 0x880, 0x890, 0x890, 0x8a0, 0x8a0, 0x8b0, 0x8b0, 0x8c0, 0x8c0, 0x8d0, 0x8e0, 0x8f0, 0x900, 0x910, 0x910, 0x910, 0x910, 0x900, 0x8f0, 0x8c0, 0x870, 0x820, 0x7e0, 0x7a0, 0x770, 0x760, 0x7a0, 0x7c0, 0x7c0, 0x6e0, 0x400, 0x3c0, 0x3c0}, {0x710, 0x710, 0x7a0, 0x7f0, 0x820, 0x830, 0x840, 0x850, 0x850, 0x860, 0x860, 0x860, 0x860, 0x860, 0x870, 0x870, 0x870, 0x880, 0x880, 0x880, 0x890, 0x890, 0x8a0, 0x8a0, 0x8b0, 0x8b0, 0x8c0, 0x8c0, 0x8e0, 0x8f0, 0x900, 0x910, 0x910, 0x910, 0x910, 0x900, 0x8e0, 0x8b0, 0x870, 0x820, 0x7e0, 0x7b0, 0x760, 0x770, 0x7a0, 0x7c0, 0x780, 0x5d0, 0x3c0, 0x3c0}, {0x680, 0x680, 0x750, 0x7b0, 0x7e0, 0x810, 0x820, 0x830, 0x840, 0x850, 0x850, 0x850, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860, 0x860, 0x870, 0x870, 0x870, 0x870, 0x880, 0x880, 0x880, 0x890, 0x8a0, 0x8b0, 0x8c0, 0x8d0, 0x8e0, 0x8f0, 0x900, 0x910, 0x910, 0x910, 0x900, 0x8f0, 0x8d0, 0x8b0, 0x840, 0x7f0, 0x790, 0x760, 0x7a0, 0x7c0, 0x7b0, 0x720} }; static int8_t baptab[305] = { 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, /* 93 padding elems */ 16, 16, 16, 16, 16, 16, 16, 16, 16, 14, 14, 14, 14, 14, 14, 14, 14, 12, 12, 12, 12, 11, 11, 11, 11, 10, 10, 10, 10, 9, 9, 9, 9, 8, 8, 8, 8, 7, 7, 7, 7, 6, 6, 6, 6, 5, 5, 5, 5, 4, 4, -3, -3, 3, 3, 3, -2, -2, -1, -1, -1, -1, -1, 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, 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, 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, 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, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 /* 148 padding elems */ }; static int bndtab[30] = {21, 22, 23, 24, 25, 26, 27, 28, 31, 34, 37, 40, 43, 46, 49, 55, 61, 67, 73, 79, 85, 97, 109, 121, 133, 157, 181, 205, 229, 253}; static int8_t latab[256] = { -64, -63, -62, -61, -60, -59, -58, -57, -56, -55, -54, -53, -52, -52, -51, -50, -49, -48, -47, -47, -46, -45, -44, -44, -43, -42, -41, -41, -40, -39, -38, -38, -37, -36, -36, -35, -35, -34, -33, -33, -32, -32, -31, -30, -30, -29, -29, -28, -28, -27, -27, -26, -26, -25, -25, -24, -24, -23, -23, -22, -22, -21, -21, -21, -20, -20, -19, -19, -19, -18, -18, -18, -17, -17, -17, -16, -16, -16, -15, -15, -15, -14, -14, -14, -13, -13, -13, -13, -12, -12, -12, -12, -11, -11, -11, -11, -10, -10, -10, -10, -10, -9, -9, -9, -9, -9, -8, -8, -8, -8, -8, -8, -7, -7, -7, -7, -7, -7, -6, -6, -6, -6, -6, -6, -6, -6, -5, -5, -5, -5, -5, -5, -5, -5, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -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, 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, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; #define UPDATE_LEAK() \ do { \ fastleak += fdecay; \ if (fastleak > psd + fgain) \ fastleak = psd + fgain; \ slowleak += sdecay; \ if (slowleak > psd + sgain) \ slowleak = psd + sgain; \ } while (0) #define COMPUTE_MASK() \ do { \ if (psd > dbknee) \ mask -= (psd - dbknee) >> 2; \ if (mask > hth [i >> halfrate]) \ mask = hth [i >> halfrate]; \ mask -= snroffset + 128 * deltba[i]; \ mask = (mask > 0) ? 0 : ((-mask) >> 5); \ mask -= floor; \ } while (0) void a52_bit_allocate (a52_state_t * state, ba_t * ba, int bndstart, int start, int end, int fastleak, int slowleak, expbap_t * expbap) { static int slowgain[4] = {0x540, 0x4d8, 0x478, 0x410}; static int dbpbtab[4] = {0xc00, 0x500, 0x300, 0x100}; static int floortab[8] = {0x910, 0x950, 0x990, 0x9d0, 0xa10, 0xa90, 0xb10, 0x1400}; int i, j; uint8_t * exp; int8_t * bap; int fdecay, fgain, sdecay, sgain, dbknee, floor, snroffset; int psd, mask; int8_t * deltba; int * hth; int halfrate; halfrate = state->halfrate; fdecay = (63 + 20 * ((state->bai >> 7) & 3)) >> halfrate; /* fdcycod */ fgain = 128 + 128 * (ba->bai & 7); /* fgaincod */ sdecay = (15 + 2 * (state->bai >> 9)) >> halfrate; /* sdcycod */ sgain = slowgain[(state->bai >> 5) & 3]; /* sgaincod */ dbknee = dbpbtab[(state->bai >> 3) & 3]; /* dbpbcod */ hth = hthtab[state->fscod]; /* * if there is no delta bit allocation, make deltba point to an area * known to contain zeroes. baptab+156 here. */ deltba = (ba->deltbae == DELTA_BIT_NONE) ? baptab + 156 : ba->deltba; floor = floortab[state->bai & 7]; /* floorcod */ snroffset = 960 - 64 * state->csnroffst - 4 * (ba->bai >> 3) + floor; floor >>= 5; exp = expbap->exp; bap = expbap->bap; i = bndstart; j = start; if (start == 0) { /* not the coupling channel */ int lowcomp; lowcomp = 0; j = end - 1; do { if (i < j) { if (exp[i+1] == exp[i] - 2) lowcomp = 384; else if (lowcomp && (exp[i+1] > exp[i])) lowcomp -= 64; } psd = 128 * exp[i]; mask = psd + fgain + lowcomp; COMPUTE_MASK (); bap[i] = (baptab+156)[mask + 4 * exp[i]]; i++; } while ((i < 3) || ((i < 7) && (exp[i] > exp[i-1]))); fastleak = psd + fgain; slowleak = psd + sgain; while (i < 7) { if (i < j) { if (exp[i+1] == exp[i] - 2) lowcomp = 384; else if (lowcomp && (exp[i+1] > exp[i])) lowcomp -= 64; } psd = 128 * exp[i]; UPDATE_LEAK (); mask = ((fastleak + lowcomp < slowleak) ? fastleak + lowcomp : slowleak); COMPUTE_MASK (); bap[i] = (baptab+156)[mask + 4 * exp[i]]; i++; } if (end == 7) /* lfe channel */ return; do { if (exp[i+1] == exp[i] - 2) lowcomp = 320; else if (lowcomp && (exp[i+1] > exp[i])) lowcomp -= 64; psd = 128 * exp[i]; UPDATE_LEAK (); mask = ((fastleak + lowcomp < slowleak) ? fastleak + lowcomp : slowleak); COMPUTE_MASK (); bap[i] = (baptab+156)[mask + 4 * exp[i]]; i++; } while (i < 20); while (lowcomp > 128) { /* two iterations maximum */ lowcomp -= 128; psd = 128 * exp[i]; UPDATE_LEAK (); mask = ((fastleak + lowcomp < slowleak) ? fastleak + lowcomp : slowleak); COMPUTE_MASK (); bap[i] = (baptab+156)[mask + 4 * exp[i]]; i++; } j = i; } do { int startband, endband; startband = j; endband = ((bndtab-20)[i] < end) ? (bndtab-20)[i] : end; psd = 128 * exp[j++]; while (j < endband) { int next, delta; next = 128 * exp[j++]; delta = next - psd; switch (delta >> 9) { case -6: case -5: case -4: case -3: case -2: psd = next; break; case -1: psd = next + latab[(-delta) >> 1]; break; case 0: psd += latab[delta >> 1]; break; } } /* minpsd = -289 */ UPDATE_LEAK (); mask = (fastleak < slowleak) ? fastleak : slowleak; COMPUTE_MASK (); i++; j = startband; do { /* max(mask+4*exp)=147=-(minpsd+fgain-deltba-snroffset)>>5+4*exp */ /* min(mask+4*exp)=-156=-(sgain-deltba-snroffset)>>5 */ bap[j] = (baptab+156)[mask + 4 * exp[j]]; } while (++j < endband); } while (j < end); }