AAC编解码，faac faad

/* ** 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: sbr_hfadj.c,v 1.23 2008/09/19 22:50:20 menno Exp $ **/ /* High Frequency adjustment */ #include "common.h" #include "structs.h" #ifdef SBR_DEC #include "sbr_syntax.h" #include "sbr_hfadj.h" #include "sbr_noise.h" /* static function declarations */ static uint8_t estimate_current_envelope(sbr_info *sbr, sbr_hfadj_info *adj, qmf_t Xsbr[MAX_NTSRHFG][64], uint8_t ch); static void calculate_gain(sbr_info *sbr, sbr_hfadj_info *adj, uint8_t ch); #ifdef SBR_LOW_POWER static void calc_gain_groups(sbr_info *sbr, sbr_hfadj_info *adj, real_t *deg, uint8_t ch); static void aliasing_reduction(sbr_info *sbr, sbr_hfadj_info *adj, real_t *deg, uint8_t ch); #endif static void hf_assembly(sbr_info *sbr, sbr_hfadj_info *adj, qmf_t Xsbr[MAX_NTSRHFG][64], uint8_t ch); uint8_t hf_adjustment(sbr_info *sbr, qmf_t Xsbr[MAX_NTSRHFG][64] #ifdef SBR_LOW_POWER ,real_t *deg /* aliasing degree */ #endif ,uint8_t ch) { ALIGN sbr_hfadj_info adj = {{{0}}}; uint8_t ret = 0; if (sbr->bs_frame_class[ch] == FIXFIX) { sbr->l_A[ch] = -1; } else if (sbr->bs_frame_class[ch] == VARFIX) { if (sbr->bs_pointer[ch] > 1) sbr->l_A[ch] = sbr->bs_pointer[ch] - 1; else sbr->l_A[ch] = -1; } else { if (sbr->bs_pointer[ch] == 0) sbr->l_A[ch] = -1; else sbr->l_A[ch] = sbr->L_E[ch] + 1 - sbr->bs_pointer[ch]; } ret = estimate_current_envelope(sbr, &adj, Xsbr, ch); if (ret > 0) return 1; calculate_gain(sbr, &adj, ch); #ifdef SBR_LOW_POWER calc_gain_groups(sbr, &adj, deg, ch); aliasing_reduction(sbr, &adj, deg, ch); #endif hf_assembly(sbr, &adj, Xsbr, ch); return 0; } static uint8_t get_S_mapped(sbr_info *sbr, uint8_t ch, uint8_t l, uint8_t current_band) { if (sbr->f[ch][l] == HI_RES) { /* in case of using f_table_high we just have 1 to 1 mapping * from bs_add_harmonic[l][k] */ if ((l >= sbr->l_A[ch]) || (sbr->bs_add_harmonic_prev[ch][current_band] && sbr->bs_add_harmonic_flag_prev[ch])) { return sbr->bs_add_harmonic[ch][current_band]; } } else { uint8_t b, lb, ub; /* in case of f_table_low we check if any of the HI_RES bands * within this LO_RES band has bs_add_harmonic[l][k] turned on * (note that borders in the LO_RES table are also present in * the HI_RES table) */ /* find first HI_RES band in current LO_RES band */ lb = 2*current_band - ((sbr->N_high & 1) ? 1 : 0); /* find first HI_RES band in next LO_RES band */ ub = 2*(current_band+1) - ((sbr->N_high & 1) ? 1 : 0); /* check all HI_RES bands in current LO_RES band for sinusoid */ for (b = lb; b < ub; b++) { if ((l >= sbr->l_A[ch]) || (sbr->bs_add_harmonic_prev[ch][b] && sbr->bs_add_harmonic_flag_prev[ch])) { if (sbr->bs_add_harmonic[ch][b] == 1) return 1; } } } return 0; } static uint8_t estimate_current_envelope(sbr_info *sbr, sbr_hfadj_info *adj, qmf_t Xsbr[MAX_NTSRHFG][64], uint8_t ch) { uint8_t m, l, j, k, k_l, k_h, p; real_t nrg, div; if (sbr->bs_interpol_freq == 1) { for (l = 0; l < sbr->L_E[ch]; l++) { uint8_t i, l_i, u_i; l_i = sbr->t_E[ch][l]; u_i = sbr->t_E[ch][l+1]; div = (real_t)(u_i - l_i); if (div == 0) div = 1; for (m = 0; m < sbr->M; m++) { nrg = 0; for (i = l_i + sbr->tHFAdj; i < u_i + sbr->tHFAdj; i++) { #ifdef FIXED_POINT #ifdef SBR_LOW_POWER nrg += ((QMF_RE(Xsbr[i][m + sbr->kx])+(1<<(REAL_BITS-1)))>>REAL_BITS)*((QMF_RE(Xsbr[i][m + sbr->kx])+(1<<(REAL_BITS-1)))>>REAL_BITS); #else nrg += ((QMF_RE(Xsbr[i][m + sbr->kx])+(1<<(REAL_BITS-1)))>>REAL_BITS)*((QMF_RE(Xsbr[i][m + sbr->kx])+(1<<(REAL_BITS-1)))>>REAL_BITS) + ((QMF_IM(Xsbr[i][m + sbr->kx])+(1<<(REAL_BITS-1)))>>REAL_BITS)*((QMF_IM(Xsbr[i][m + sbr->kx])+(1<<(REAL_BITS-1)))>>REAL_BITS); #endif #else nrg += MUL_R(QMF_RE(Xsbr[i][m + sbr->kx]), QMF_RE(Xsbr[i][m + sbr->kx])) #ifndef SBR_LOW_POWER + MUL_R(QMF_IM(Xsbr[i][m + sbr->kx]), QMF_IM(Xsbr[i][m + sbr->kx])) #endif ; #endif } sbr->E_curr[ch][m][l] = nrg / div; #ifdef SBR_LOW_POWER #ifdef FIXED_POINT sbr->E_curr[ch][m][l] <<= 1; #else sbr->E_curr[ch][m][l] *= 2; #endif #endif } } } else { for (l = 0; l < sbr->L_E[ch]; l++) { for (p = 0; p < sbr->n[sbr->f[ch][l]]; p++) { k_l = sbr->f_table_res[sbr->f[ch][l]][p]; k_h = sbr->f_table_res[sbr->f[ch][l]][p+1]; for (k = k_l; k < k_h; k++) { uint8_t i, l_i, u_i; nrg = 0; l_i = sbr->t_E[ch][l]; u_i = sbr->t_E[ch][l+1]; div = (real_t)((u_i - l_i)*(k_h - k_l)); if (div == 0) div = 1; for (i = l_i + sbr->tHFAdj; i < u_i + sbr->tHFAdj; i++) { for (j = k_l; j < k_h; j++) { #ifdef FIXED_POINT #ifdef SBR_LOW_POWER nrg += ((QMF_RE(Xsbr[i][j])+(1<<(REAL_BITS-1)))>>REAL_BITS)*((QMF_RE(Xsbr[i][j])+(1<<(REAL_BITS-1)))>>REAL_BITS); #else nrg += ((QMF_RE(Xsbr[i][j])+(1<<(REAL_BITS-1)))>>REAL_BITS)*((QMF_RE(Xsbr[i][j])+(1<<(REAL_BITS-1)))>>REAL_BITS) + ((QMF_IM(Xsbr[i][j])+(1<<(REAL_BITS-1)))>>REAL_BITS)*((QMF_IM(Xsbr[i][j])+(1<<(REAL_BITS-1)))>>REAL_BITS); #endif #else nrg += MUL_R(QMF_RE(Xsbr[i][j]), QMF_RE(Xsbr[i][j])) #ifndef SBR_LOW_POWER + MUL_R(QMF_IM(Xsbr[i][j]), QMF_IM(Xsbr[i][j])) #endif ; #endif } } sbr->E_curr[ch][k - sbr->kx][l] = nrg / div; #ifdef SBR_LOW_POWER #ifdef FIXED_POINT