ref: 42ce0306d62d795bb9ead55d71c1ae418657d048
dir: /libfaad/sbr_e_nf.c/
/* ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding ** Copyright (C) 2003 M. Bakker, Ahead Software 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. ** ** Commercial non-GPL licensing of this software is possible. ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com. ** ** $Id: sbr_e_nf.c,v 1.7 2003/11/02 20:24:05 menno Exp $ **/ #include "common.h" #include "structs.h" #ifdef SBR_DEC #include <stdlib.h> #include "sbr_syntax.h" #include "sbr_e_nf.h" void extract_envelope_data(sbr_info *sbr, uint8_t ch) { uint8_t l, k; for (l = 0; l < sbr->L_E[ch]; l++) { if (sbr->bs_df_env[ch][l] == 0) { for (k = 1; k < sbr->n[sbr->f[ch][l]]; k++) { sbr->E[ch][k][l] = sbr->E[ch][k - 1][l] + sbr->E[ch][k][l]; } } else { /* bs_df_env == 1 */ uint8_t g = (l == 0) ? sbr->f_prev[ch] : sbr->f[ch][l-1]; int16_t E_prev; if (sbr->f[ch][l] == g) { for (k = 0; k < sbr->n[sbr->f[ch][l]]; k++) { if (l == 0) E_prev = sbr->E_prev[ch][k]; else E_prev = sbr->E[ch][k][l - 1]; sbr->E[ch][k][l] = E_prev + sbr->E[ch][k][l]; } } else if ((g == 1) && (sbr->f[ch][l] == 0)) { uint8_t i; for (k = 0; k < sbr->n[sbr->f[ch][l]]; k++) { for (i = 0; i < sbr->N_high; i++) { if (sbr->f_table_res[HI_RES][i] == sbr->f_table_res[LO_RES][k]) { if (l == 0) E_prev = sbr->E_prev[ch][i]; else E_prev = sbr->E[ch][i][l - 1]; sbr->E[ch][k][l] = E_prev + sbr->E[ch][k][l]; } } } } else if ((g == 0) && (sbr->f[ch][l] == 1)) { uint8_t i; for (k = 0; k < sbr->n[sbr->f[ch][l]]; k++) { for (i = 0; i < sbr->N_low; i++) { if ((sbr->f_table_res[LO_RES][i] <= sbr->f_table_res[HI_RES][k]) && (sbr->f_table_res[HI_RES][k] < sbr->f_table_res[LO_RES][i + 1])) { if (l == 0) E_prev = sbr->E_prev[ch][i]; else E_prev = sbr->E[ch][i][l - 1]; sbr->E[ch][k][l] = E_prev + sbr->E[ch][k][l]; } } } } } } } void extract_noise_floor_data(sbr_info *sbr, uint8_t ch) { uint8_t l, k; for (l = 0; l < sbr->L_Q[ch]; l++) { if (sbr->bs_df_noise[ch][l] == 0) { for (k = 1; k < sbr->N_Q; k++) { sbr->Q[ch][k][l] = sbr->Q[ch][k][l] + sbr->Q[ch][k-1][l]; } } else { if (l == 0) { for (k = 0; k < sbr->N_Q; k++) { sbr->Q[ch][k][l] = sbr->Q_prev[ch][k] + sbr->Q[ch][k][0]; } } else { for (k = 0; k < sbr->N_Q; k++) { sbr->Q[ch][k][l] = sbr->Q[ch][k][l - 1] + sbr->Q[ch][k][l]; } } } } } /* FIXME: pow() not needed */ void envelope_noise_dequantisation(sbr_info *sbr, uint8_t ch) { if (sbr->bs_coupling == 0) { uint8_t l, k; real_t amp = (sbr->amp_res[ch]) ? 1.0f : 0.5f; for (l = 0; l < sbr->L_E[ch]; l++) { for (k = 0; k < sbr->n[sbr->f[ch][l]]; k++) { /* +6 for the *64 */ sbr->E_orig[ch][k][l] = (real_t)pow(2, sbr->E[ch][k][l]*amp + 6); } } for (l = 0; l < sbr->L_Q[ch]; l++) { for (k = 0; k < sbr->N_Q; k++) { if (sbr->Q[ch][k][l] < 0 || sbr->Q[ch][k][l] > 30) { sbr->Q_orig[ch][k][l] = 0; } else { sbr->Q_orig[ch][k][l] = (real_t)pow(2, NOISE_FLOOR_OFFSET - sbr->Q[ch][k][l]); } } } } } void unmap_envelope_noise(sbr_info *sbr) { uint8_t l, k; real_t amp0 = (sbr->amp_res[0]) ? (real_t)1.0 : (real_t)0.5; real_t amp1 = (sbr->amp_res[1]) ? (real_t)1.0 : (real_t)0.5; for (l = 0; l < sbr->L_E[0]; l++) { for (k = 0; k < sbr->n[sbr->f[0][l]]; k++) { real_t l_temp, r_temp; /* +6: * 64 ; +1: * 2 */ l_temp = (real_t)pow(2, sbr->E[0][k][l]*amp0 + 7); /* UN_MAP removed: (x / 4096) same as (x >> 12) */ r_temp = (real_t)pow(2, sbr->E[1][k][l]*amp1 - 12); sbr->E_orig[1][k][l] = l_temp / ((real_t)1.0 + r_temp); sbr->E_orig[0][k][l] = MUL(r_temp, sbr->E_orig[1][k][l]); } } for (l = 0; l < sbr->L_Q[0]; l++) { for (k = 0; k < sbr->N_Q; k++) { if ((sbr->Q[0][k][l] < 0 || sbr->Q[0][k][l] > 30) || (sbr->Q[1][k][l] < 0 || sbr->Q[1][k][l] > 24 /* 2*panOffset(1) */)) { sbr->Q_orig[0][k][l] = 0; sbr->Q_orig[1][k][l] = 0; } else { real_t l_temp, r_temp; l_temp = (real_t)pow(2.0, NOISE_FLOOR_OFFSET - sbr->Q[0][k][l] + 1); r_temp = (real_t)pow(2.0, sbr->Q[1][k][l] - 12); sbr->Q_orig[1][k][l] = l_temp / ((real_t)1.0 + r_temp); sbr->Q_orig[0][k][l] = MUL(r_temp, sbr->Q_orig[1][k][l]); } } } } #endif