2 ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
3 ** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com
5 ** This program is free software; you can redistribute it and/or modify
6 ** it under the terms of the GNU General Public License as published by
7 ** the Free Software Foundation; either version 2 of the License, or
8 ** (at your option) any later version.
10 ** This program is distributed in the hope that it will be useful,
11 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
12 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 ** GNU General Public License for more details.
15 ** You should have received a copy of the GNU General Public License
16 ** along with this program; if not, write to the Free Software
17 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 ** Any non-GPL usage of this software or parts of this software is strictly
22 ** The "appropriate copyright message" mentioned in section 2c of the GPLv2
23 ** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"
25 ** Commercial non-GPL licensing of this software is possible.
26 ** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
28 ** $Id: ssr_fb.c,v 1.17 2007/11/01 12:33:36 menno Exp $
44 fb_info *ssr_filter_bank_init(uint16_t frame_len)
46 uint16_t nshort = frame_len/8;
48 fb_info *fb = (fb_info*)faad_malloc(sizeof(fb_info));
49 memset(fb, 0, sizeof(fb_info));
52 fb->mdct256 = faad_mdct_init(2*nshort);
53 fb->mdct2048 = faad_mdct_init(2*frame_len);
55 fb->long_window[0] = sine_long_256;
56 fb->short_window[0] = sine_short_32;
57 fb->long_window[1] = kbd_long_256;
58 fb->short_window[1] = kbd_short_32;
63 void ssr_filter_bank_end(fb_info *fb)
65 faad_mdct_end(fb->mdct256);
66 faad_mdct_end(fb->mdct2048);
68 if (fb) faad_free(fb);
71 static INLINE void imdct_ssr(fb_info *fb, real_t *in_data,
72 real_t *out_data, uint16_t len)
86 faad_imdct(mdct, in_data, out_data);
89 /* NON-overlapping inverse filterbank for use with SSR */
90 void ssr_ifilter_bank(fb_info *fb, uint8_t window_sequence, uint8_t window_shape,
91 uint8_t window_shape_prev, real_t *freq_in,
92 real_t *time_out, uint16_t frame_len)
98 real_t *window_long_prev;
100 real_t *window_short_prev;
102 uint16_t nlong = frame_len;
103 uint16_t nshort = frame_len/8;
104 uint16_t trans = nshort/2;
106 uint16_t nflat_ls = (nlong-nshort)/2;
108 transf_buf = (real_t*)faad_malloc(2*nlong*sizeof(real_t));
110 window_long = fb->long_window[window_shape];
111 window_long_prev = fb->long_window[window_shape_prev];
112 window_short = fb->short_window[window_shape];
113 window_short_prev = fb->short_window[window_shape_prev];
115 switch (window_sequence)
117 case ONLY_LONG_SEQUENCE:
118 imdct_ssr(fb, freq_in, transf_buf, 2*nlong);
119 for (i = nlong-1; i >= 0; i--)
121 time_out[i] = MUL_R_C(transf_buf[i],window_long_prev[i]);
122 time_out[nlong+i] = MUL_R_C(transf_buf[nlong+i],window_long[nlong-1-i]);
126 case LONG_START_SEQUENCE:
127 imdct_ssr(fb, freq_in, transf_buf, 2*nlong);
128 for (i = 0; i < nlong; i++)
129 time_out[i] = MUL_R_C(transf_buf[i],window_long_prev[i]);
130 for (i = 0; i < nflat_ls; i++)
131 time_out[nlong+i] = transf_buf[nlong+i];
132 for (i = 0; i < nshort; i++)
133 time_out[nlong+nflat_ls+i] = MUL_R_C(transf_buf[nlong+nflat_ls+i],window_short[nshort-i-1]);
134 for (i = 0; i < nflat_ls; i++)
135 time_out[nlong+nflat_ls+nshort+i] = 0;
138 case EIGHT_SHORT_SEQUENCE:
139 imdct_ssr(fb, freq_in+0*nshort, transf_buf+2*nshort*0, 2*nshort);
140 imdct_ssr(fb, freq_in+1*nshort, transf_buf+2*nshort*1, 2*nshort);
141 imdct_ssr(fb, freq_in+2*nshort, transf_buf+2*nshort*2, 2*nshort);
142 imdct_ssr(fb, freq_in+3*nshort, transf_buf+2*nshort*3, 2*nshort);
143 imdct_ssr(fb, freq_in+4*nshort, transf_buf+2*nshort*4, 2*nshort);
144 imdct_ssr(fb, freq_in+5*nshort, transf_buf+2*nshort*5, 2*nshort);
145 imdct_ssr(fb, freq_in+6*nshort, transf_buf+2*nshort*6, 2*nshort);
146 imdct_ssr(fb, freq_in+7*nshort, transf_buf+2*nshort*7, 2*nshort);
147 for(i = nshort-1; i >= 0; i--)
149 time_out[i+0*nshort] = MUL_R_C(transf_buf[nshort*0+i],window_short_prev[i]);
150 time_out[i+1*nshort] = MUL_R_C(transf_buf[nshort*1+i],window_short[i]);
151 time_out[i+2*nshort] = MUL_R_C(transf_buf[nshort*2+i],window_short_prev[i]);
152 time_out[i+3*nshort] = MUL_R_C(transf_buf[nshort*3+i],window_short[i]);
153 time_out[i+4*nshort] = MUL_R_C(transf_buf[nshort*4+i],window_short_prev[i]);
154 time_out[i+5*nshort] = MUL_R_C(transf_buf[nshort*5+i],window_short[i]);
155 time_out[i+6*nshort] = MUL_R_C(transf_buf[nshort*6+i],window_short_prev[i]);
156 time_out[i+7*nshort] = MUL_R_C(transf_buf[nshort*7+i],window_short[i]);
157 time_out[i+8*nshort] = MUL_R_C(transf_buf[nshort*8+i],window_short_prev[i]);
158 time_out[i+9*nshort] = MUL_R_C(transf_buf[nshort*9+i],window_short[i]);
159 time_out[i+10*nshort] = MUL_R_C(transf_buf[nshort*10+i],window_short_prev[i]);
160 time_out[i+11*nshort] = MUL_R_C(transf_buf[nshort*11+i],window_short[i]);
161 time_out[i+12*nshort] = MUL_R_C(transf_buf[nshort*12+i],window_short_prev[i]);
162 time_out[i+13*nshort] = MUL_R_C(transf_buf[nshort*13+i],window_short[i]);
163 time_out[i+14*nshort] = MUL_R_C(transf_buf[nshort*14+i],window_short_prev[i]);
164 time_out[i+15*nshort] = MUL_R_C(transf_buf[nshort*15+i],window_short[i]);
168 case LONG_STOP_SEQUENCE:
169 imdct_ssr(fb, freq_in, transf_buf, 2*nlong);
170 for (i = 0; i < nflat_ls; i++)
172 for (i = 0; i < nshort; i++)
173 time_out[nflat_ls+i] = MUL_R_C(transf_buf[nflat_ls+i],window_short_prev[i]);
174 for (i = 0; i < nflat_ls; i++)
175 time_out[nflat_ls+nshort+i] = transf_buf[nflat_ls+nshort+i];
176 for (i = 0; i < nlong; i++)
177 time_out[nlong+i] = MUL_R_C(transf_buf[nlong+i],window_long[nlong-1-i]);
181 faad_free(transf_buf);