ref: 7592cc985f084dbfab7f941100d1f09b33a43e22
dir: /libfaad/huffman.h/
/* ** FAAD - Freeware Advanced Audio Decoder ** Copyright (C) 2002 M. Bakker ** ** 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. ** ** $Id: huffman.h,v 1.7 2002/05/31 18:06:49 menno Exp $ **/ #ifndef __HUFFMAN_H__ #define __HUFFMAN_H__ #ifdef __cplusplus extern "C" { #endif #include <stdlib.h> #ifdef ANALYSIS #include <stdio.h> #endif #include "bits.h" #include "codebook/hcb.h" static INLINE uint8_t huffman_scale_factor(bitfile *ld) { uint16_t offset = 0; while (hcb_sf[offset][1]) { uint8_t b = faad_get1bit(ld); offset += hcb_sf[offset][b]; } return hcb_sf[offset][0]; } static hcb *hcb_table[] = { 0, hcb1_1, hcb2_1, 0, hcb4_1, 0, hcb6_1, 0, hcb8_1, 0, hcb10_1, hcb11_1 }; static hcb_2_quad *hcb_2_quad_table[] = { 0, hcb1_2, hcb2_2, 0, hcb4_2, 0, 0, 0, 0, 0, 0, 0 }; static hcb_2_pair *hcb_2_pair_table[] = { 0, 0, 0, 0, 0, 0, hcb6_2, 0, hcb8_2, 0, hcb10_2, hcb11_2 }; static hcb_bin_pair *hcb_bin_table[] = { 0, 0, 0, 0, 0, hcb5, 0, hcb7, 0, hcb9, 0, 0 }; static uint8_t hcbN[] = { 0, 5, 5, 0, 5, 0, 5, 0, 5, 0, 6, 5 }; static INLINE void huffman_spectral_data(uint8_t cb, bitfile *ld, int16_t *sp) { uint32_t cw; uint16_t offset = 0; uint8_t extra_bits; switch (cb) { case 1: /* 2-step method for data quadruples */ case 2: case 4: 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); } 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: #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: /* TODO: If ER is used, some extra error checking should be done */ if (cb >= 16) cb = 11; #endif 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); } 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 = faad_get1bit(ld); 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 = faad_get1bit(ld); 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; } } 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 int32_t huffman_getescape(bitfile *ld, int16_t sp) { uint8_t neg, i; int32_t j, 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; } } #if 0 if (i > 16) { off = faad_getbits(ld, i-16 DEBUGVAR(1,7,"huffman_getescape(): escape, first part")) << 16; off |= faad_getbits(ld, 16 DEBUGVAR(1,8,"huffman_getescape(): escape, second part")); } else { #endif off = faad_getbits(ld, i DEBUGVAR(1,9,"huffman_getescape(): escape")); #if 0 } #endif j = off + (1<<i); if (neg) j = -j; return j; } #ifdef __cplusplus } #endif #endif