ref: b85c7449be81f0f707dca329c2fc67733d4c6856
dir: /libfaad/huffman.c/
/* ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding ** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com ** ** This program 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. ** ** This program 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. ** ** Any non-GPL usage of this software or parts of this software is strictly ** forbidden. ** ** The "appropriate copyright message" mentioned in section 2c of the GPLv2 ** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com" ** ** Commercial non-GPL licensing of this software is possible. ** For more info contact Nero AG through Mpeg4AAClicense@nero.com. ** ** $Id: huffman.c,v 1.26 2007/11/01 12:33:30 menno Exp $ **/ #include "common.h" #include "structs.h" #include <stdlib.h> #ifdef ANALYSIS #include <stdio.h> #endif #include "bits.h" #include "huffman.h" #include "codebook/hcb.h" /* static function declarations */ static INLINE void huffman_sign_bits(bitfile *ld, int16_t *sp, uint8_t len); static INLINE int16_t huffman_getescape(bitfile *ld, int16_t sp); static uint8_t huffman_2step_quad(uint8_t cb, bitfile *ld, int16_t *sp); static uint8_t huffman_2step_quad_sign(uint8_t cb, bitfile *ld, int16_t *sp); static uint8_t huffman_2step_pair(uint8_t cb, bitfile *ld, int16_t *sp); static uint8_t huffman_2step_pair_sign(uint8_t cb, bitfile *ld, int16_t *sp); static uint8_t huffman_binary_quad(uint8_t cb, bitfile *ld, int16_t *sp); static uint8_t huffman_binary_quad_sign(uint8_t cb, bitfile *ld, int16_t *sp); static uint8_t huffman_binary_pair(uint8_t cb, bitfile *ld, int16_t *sp); static uint8_t huffman_binary_pair_sign(uint8_t cb, bitfile *ld, int16_t *sp); static int16_t huffman_codebook(uint8_t i); static void vcb11_check_LAV(uint8_t cb, int16_t *sp); int8_t huffman_scale_factor(bitfile *ld) { uint16_t offset = 0; while (hcb_sf[offset][1]) { uint8_t b = faad_get1bit(ld DEBUGVAR(1,255,"huffman_scale_factor()")); offset += hcb_sf[offset][b]; if (offset > 240) { /* printf("ERROR: offset into hcb_sf = %d >240!\n", offset); */ return -1; } } return hcb_sf[offset][0]; } hcb *hcb_table[] = { 0, hcb1_1, hcb2_1, 0, hcb4_1, 0, hcb6_1, 0, hcb8_1, 0, hcb10_1, hcb11_1 }; hcb_2_quad *hcb_2_quad_table[] = { 0, hcb1_2, hcb2_2, 0, hcb4_2, 0, 0, 0, 0, 0, 0, 0 }; hcb_2_pair *hcb_2_pair_table[] = { 0, 0, 0, 0, 0, 0, hcb6_2, 0, hcb8_2, 0, hcb10_2, hcb11_2 }; hcb_bin_pair *hcb_bin_table[] = { 0, 0, 0, 0, 0, hcb5, 0, hcb7, 0, hcb9, 0, 0 }; uint8_t hcbN[] = { 0, 5, 5, 0, 5, 0, 5, 0, 5, 0, 6, 5 }; /* defines whether a huffman codebook is unsigned or not */ /* Table 4.6.2 */ uint8_t unsigned_cb[] = { 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, /* codebook 16 to 31 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 }; int hcb_2_quad_table_size[] = { 0, 114, 86, 0, 185, 0, 0, 0, 0, 0, 0, 0 }; int hcb_2_pair_table_size[] = { 0, 0, 0, 0, 0, 0, 126, 0, 83, 0, 210, 373 }; int hcb_bin_table_size[] = { 0, 0, 0, 161, 0, 161, 0, 127, 0, 337, 0, 0 }; static INLINE void huffman_sign_bits(bitfile *ld, int16_t *sp, uint8_t len) { uint8_t i; for (i = 0; i < len; i++) { if(sp[i]) { if(faad_get1bit(ld DEBUGVAR(1,5,"huffman_sign_bits(): sign bit")) & 1) { sp[i] = -sp[i]; } } } } static INLINE int16_t huffman_getescape(bitfile *ld, int16_t sp) { uint8_t neg, i; int16_t j; int16_t off; if (sp < 0) { if (sp != -16) return sp; neg = 1; } else { if (sp != 16) return sp; neg = 0; } for (i = 4; ; i++) { if (faad_get1bit(ld DEBUGVAR(1,6,"huffman_getescape(): escape size")) == 0) { break; } } off = (int16_t)faad_getbits(ld, i DEBUGVAR(1,9,"huffman_getescape(): escape")); j = off | (1<<i); if (neg) j = -j; return j; } static uint8_t huffman_2step_quad(uint8_t cb, bitfile *ld, int16_t *sp) { uint32_t cw; uint16_t offset = 0; uint8_t extra_bits; cw = faad_showbits(ld, hcbN[cb]); offset = hcb_table[cb][cw].offset; extra_bits = hcb_table[cb][cw].extra_bits; if (extra_bits) { /* we know for sure it's more than hcbN[cb] bits long */ faad_flushbits(ld, hcbN[cb]); offset += (uint16_t)faad_showbits(ld, extra_bits); faad_flushbits(ld, hcb_2_quad_table[cb][offset].bits - hcbN[cb]); } else { faad_flushbits(ld, hcb_2_quad_table[cb][offset].bits); } if (offset > hcb_2_quad_table_size[cb]) { /* printf("ERROR: offset into hcb_2_quad_table = %d >%d!\n", offset, hcb_2_quad_table_size[cb]); */ return 10; } sp[0] = hcb_2_quad_table[cb][offset].x; sp[1] = hcb_2_quad_table[cb][offset].y; sp[2] = hcb_2_quad_table[cb][offset].v; sp[3] = hcb_2_quad_table[cb][offset].w; return 0; } static uint8_t huffman_2step_quad_sign(uint8_t cb, bitfile *ld, int16_t *sp) { uint8_t err = huffman_2step_quad(cb, ld, sp); huffman_sign_bits(ld, sp, QUAD_LEN); return err; } static uint8_t huffman_2step_pair(uint8_t cb, bitfile *ld, int16_t *sp) { uint32_t cw; uint16_t offset = 0; uint8_t extra_bits; cw = faad_showbits(ld, hcbN[cb]); offset = hcb_table[cb][cw].offset; extra_bits = hcb_table[cb][cw].extra_bits; if (extra_bits) { /* we know for sure it's more than hcbN[cb] bits long */ faad_flushbits(ld, hcbN[cb]); offset += (uint16_t)faad_showbits(ld, extra_bits); faad_flushbits(ld, hcb_2_pair_table[cb][offset].bits - hcbN[cb]); } else { faad_flushbits(ld, hcb_2_pair_table[cb][offset].bits); } if (offset > hcb_2_pair_table_size[cb]) { /* printf("ERROR: offset into hcb_2_pair_table = %d >%d!\n", offset, hcb_2_pair_table_size[cb]); */ return 10; } sp[0] = hcb_2_pair_table[cb][offset].x; sp[1] = hcb_2_pair_table[cb][offset].y; return 0; } static uint8_t huffman_2step_pair_sign(uint8_t cb, bitfile *ld, int16_t *sp) { uint8_t err = huffman_2step_pair(cb, ld, sp); huffman_sign_bits(ld, sp, PAIR_LEN); return err; } static uint8_t huffman_binary_quad(uint8_t cb, bitfile *ld, int16_t *sp) { uint16_t offset = 0; while (!hcb3[offset].is_leaf) { uint8_t b = faad_get1bit(ld DEBUGVAR(1,255,"huffman_spectral_data():3")); offset += hcb3[offset].data[b]; } if (offset > hcb_bin_table_size[cb]) { /* printf("ERROR: offset into hcb_bin_table = %d >%d!\n", offset, hcb_bin_table_size[cb]); */ return 10; } sp[0] = hcb3[offset].data[0]; sp[1] = hcb3[offset].data[1]; sp[2] = hcb3[offset].data[2]; sp[3] = hcb3[offset].data[3]; return 0; } static uint8_t huffman_binary_quad_sign(uint8_t cb, bitfile *ld, int16_t *sp) { uint8_t err = huffman_binary_quad(cb, ld, sp); huffman_sign_bits(ld, sp, QUAD_LEN); return err; } static uint8_t huffman_binary_pair(uint8_t cb, bitfile *ld, int16_t *sp) { uint16_t offset = 0; while (!hcb_bin_table[cb][offset].is_leaf) { uint8_t b = faad_get1bit(ld DEBUGVAR(1,255,"huffman_spectral_data():9")); offset += hcb_bin_table[cb][offset].data[b]; } if (offset > hcb_bin_table_size[cb]) { /* printf("ERROR: offset into hcb_bin_table = %d >%d!\n", offset, hcb_bin_table_size[cb]); */ return 10; } sp[0] = hcb_bin_table[cb][offset].data[0]; sp[1] = hcb_bin_table[cb][offset].data[1]; return 0; } static uint8_t huffman_binary_pair_sign(uint8_t cb, bitfile *ld, int16_t *sp) { uint8_t err = huffman_binary_pair(cb, ld, sp); huffman_sign_bits(ld, sp, PAIR_LEN); return err; } static int16_t huffman_codebook(uint8_t i) { static const uint32_t data = 16428320; if (i == 0) return (int16_t)(data >> 16) & 0xFFFF; else return (int16_t)data & 0xFFFF; } static void vcb11_check_LAV(uint8_t cb, int16_t *sp) { static const uint16_t vcb11_LAV_tab[] = { 16, 31, 47, 63, 95, 127, 159, 191, 223, 255, 319, 383, 511, 767, 1023, 2047 }; uint16_t max = 0; if (cb < 16 || cb > 31) return; max = vcb11_LAV_tab[cb - 16]; if ((abs(sp[0]) > max) || (abs(sp[1]) > max)) { sp[0] = 0; sp[1] = 0; } } uint8_t huffman_spectral_data(uint8_t cb, bitfile *ld, int16_t *sp) { switch (cb) { case 1: /* 2-step method for data quadruples */ case 2: return huffman_2step_quad(cb, ld, sp); case 3: /* binary search for data quadruples */ return huffman_binary_quad_sign(cb, ld, sp); case 4: /* 2-step method for data quadruples */ return huffman_2step_quad_sign(cb, ld, sp); case 5: /* binary search for data pairs */ return huffman_binary_pair(cb, ld, sp); case 6: /* 2-step method for data pairs */ return huffman_2step_pair(cb, ld, sp); case 7: /* binary search for data pairs */ case 9: return huffman_binary_pair_sign(cb, ld, sp); case 8: /* 2-step method for data pairs */ case 10: return huffman_2step_pair_sign(cb, ld, sp); case 12: { uint8_t err = huffman_2step_pair(11, ld, sp); sp[0] = huffman_codebook(0); sp[1] = huffman_codebook(1); return err; } case 11: { uint8_t err = huffman_2step_pair_sign(11, ld, sp); sp[0] = huffman_getescape(ld, sp[0]); sp[1] = huffman_getescape(ld, sp[1]); return err; } #ifdef ERROR_RESILIENCE /* VCB11 uses codebook 11 */ case 16: case 17: case 18: case 19: case 20: case 21: case 22: case 23: case 24: case 25: case 26: case 27: case 28: case 29: case 30: case 31: { uint8_t err = huffman_2step_pair_sign(11, ld, sp); sp[0] = huffman_getescape(ld, sp[0]); sp[1] = huffman_getescape(ld, sp[1]); /* check LAV (Largest Absolute Value) */ /* this finds errors in the ESCAPE signal */ vcb11_check_LAV(cb, sp); return err; } #endif default: /* Non existent codebook number, something went wrong */ return 11; } return 0; } #ifdef ERROR_RESILIENCE /* Special version of huffman_spectral_data Will not read from a bitfile but a bits_t structure. Will keep track of the bits decoded and return the number of bits remaining. Do not read more than ld->len, return -1 if codeword would be longer */ int8_t huffman_spectral_data_2(uint8_t cb, bits_t *ld, int16_t *sp) { uint32_t cw; uint16_t offset = 0; uint8_t extra_bits; uint8_t i, vcb11 = 0; switch (cb) { case 1: /* 2-step method for data quadruples */ case 2: case 4: cw = showbits_hcr(ld, hcbN[cb]); offset = hcb_table[cb][cw].offset; extra_bits = hcb_table[cb][cw].extra_bits; if (extra_bits) { /* we know for sure it's more than hcbN[cb] bits long */ if ( flushbits_hcr(ld, hcbN[cb]) ) return -1; offset += (uint16_t)showbits_hcr(ld, extra_bits); if ( flushbits_hcr(ld, hcb_2_quad_table[cb][offset].bits - hcbN[cb]) ) return -1; } else { if ( flushbits_hcr(ld, hcb_2_quad_table[cb][offset].bits) ) return -1; } sp[0] = hcb_2_quad_table[cb][offset].x; sp[1] = hcb_2_quad_table[cb][offset].y; sp[2] = hcb_2_quad_table[cb][offset].v; sp[3] = hcb_2_quad_table[cb][offset].w; break; case 6: /* 2-step method for data pairs */ case 8: case 10: case 11: /* VCB11 uses codebook 11 */ case 16: case 17: case 18: case 19: case 20: case 21: case 22: case 23: case 24: case 25: case 26: case 27: case 28: case 29: case 30: case 31: if (cb >= 16) { /* store the virtual codebook */ vcb11 = cb; cb = 11; } cw = showbits_hcr(ld, hcbN[cb]); offset = hcb_table[cb][cw].offset; extra_bits = hcb_table[cb][cw].extra_bits; if (extra_bits) { /* we know for sure it's more than hcbN[cb] bits long */ if ( flushbits_hcr(ld, hcbN[cb]) ) return -1; offset += (uint16_t)showbits_hcr(ld, extra_bits); if ( flushbits_hcr(ld, hcb_2_pair_table[cb][offset].bits - hcbN[cb]) ) return -1; } else { if ( flushbits_hcr(ld, hcb_2_pair_table[cb][offset].bits) ) return -1; } sp[0] = hcb_2_pair_table[cb][offset].x; sp[1] = hcb_2_pair_table[cb][offset].y; break; case 3: /* binary search for data quadruples */ while (!hcb3[offset].is_leaf) { uint8_t b; if ( get1bit_hcr(ld, &b) ) return -1; offset += hcb3[offset].data[b]; } sp[0] = hcb3[offset].data[0]; sp[1] = hcb3[offset].data[1]; sp[2] = hcb3[offset].data[2]; sp[3] = hcb3[offset].data[3]; break; case 5: /* binary search for data pairs */ case 7: case 9: while (!hcb_bin_table[cb][offset].is_leaf) { uint8_t b; if (get1bit_hcr(ld, &b) ) return -1; offset += hcb_bin_table[cb][offset].data[b]; } sp[0] = hcb_bin_table[cb][offset].data[0]; sp[1] = hcb_bin_table[cb][offset].data[1]; break; } /* decode sign bits */ if (unsigned_cb[cb]) { for(i = 0; i < ((cb < FIRST_PAIR_HCB) ? QUAD_LEN : PAIR_LEN); i++) { if(sp[i]) { uint8_t b; if ( get1bit_hcr(ld, &b) ) return -1; if (b != 0) { sp[i] = -sp[i]; } } } } /* decode huffman escape bits */ if ((cb == ESC_HCB) || (cb >= 16)) { uint8_t k; for (k = 0; k < 2; k++) { if ((sp[k] == 16) || (sp[k] == -16)) { uint8_t neg, i; int32_t j; uint32_t off; neg = (sp[k] < 0) ? 1 : 0; for (i = 4; ; i++) { uint8_t b; if (get1bit_hcr(ld, &b)) return -1; if (b == 0) break; } if (getbits_hcr(ld, i, &off)) return -1; j = off + (1<<i); sp[k] = (int16_t)((neg) ? -j : j); } } if (vcb11 != 0) { /* check LAV (Largest Absolute Value) */ /* this finds errors in the ESCAPE signal */ vcb11_check_LAV(vcb11, sp); } } return ld->len; } #endif