libfaad2/ssr_fb.c

   1 /*
   2 ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
   3 ** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
   4 **
   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.
   9 **
  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.
  14 **
  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.
  18 **
  19 ** Any non-GPL usage of this software or parts of this software is strictly
  20 ** forbidden.
  21 **
  22 ** Commercial non-GPL licensing of this software is possible.
  23 ** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
  24 **
  25 ** $Id: ssr_fb.c,v 1.13 2004/09/04 14:56:29 menno Exp $
  26 **/
  27
  28 #include "common.h"
  29 #include "structs.h"
  30
  31 #ifdef SSR_DEC
  32
  33 #include <string.h>
  34 #include <stdlib.h>
  35 #include "syntax.h"
  36 #include "filtbank.h"
  37 #include "mdct.h"
  38 #include "ssr_fb.h"
  39 #include "ssr_win.h"
  40
  41 fb_info *ssr_filter_bank_init(uint16_t frame_len)
  42 {
  43     uint16_t nshort = frame_len/8;
  44
  45     fb_info *fb = (fb_info*)faad_malloc(sizeof(fb_info));
  46     memset(fb, 0, sizeof(fb_info));
  47
  48     /* normal */
  49     fb->mdct256 = faad_mdct_init(2*nshort);
  50     fb->mdct2048 = faad_mdct_init(2*frame_len);
  51
  52     fb->long_window[0]  = sine_long_256;
  53     fb->short_window[0] = sine_short_32;
  54     fb->long_window[1]  = kbd_long_256;
  55     fb->short_window[1] = kbd_short_32;
  56
  57     return fb;
  58 }
  59
  60 void ssr_filter_bank_end(fb_info *fb)
  61 {
  62     faad_mdct_end(fb->mdct256);
  63     faad_mdct_end(fb->mdct2048);
  64
  65     if (fb) faad_free(fb);
  66 }
  67
  68 static INLINE void imdct_ssr(fb_info *fb, real_t *in_data,
  69                              real_t *out_data, uint16_t len)
  70 {
  71     mdct_info *mdct;
  72
  73     switch (len)
  74     {
  75     case 512:
  76         mdct = fb->mdct2048;
  77         break;
  78     case 64:
  79         mdct = fb->mdct256;
  80         break;
  81     }
  82
  83     faad_imdct(mdct, in_data, out_data);
  84 }
  85
  86 /* NON-overlapping inverse filterbank for use with SSR */
  87 void ssr_ifilter_bank(fb_info *fb, uint8_t window_sequence, uint8_t window_shape,
  88                       uint8_t window_shape_prev, real_t *freq_in,
  89                       real_t *time_out, uint16_t frame_len)
  90 {
  91     int16_t i;
  92     real_t *transf_buf;
  93
  94     real_t *window_long;
  95     real_t *window_long_prev;
  96     real_t *window_short;
  97     real_t *window_short_prev;
  98
  99     uint16_t nlong = frame_len;
 100     uint16_t nshort = frame_len/8;
 101     uint16_t trans = nshort/2;
 102
 103     uint16_t nflat_ls = (nlong-nshort)/2;
 104
 105     transf_buf = (real_t*)faad_malloc(2*nlong*sizeof(real_t));
 106
 107     window_long       = fb->long_window[window_shape];
 108     window_long_prev  = fb->long_window[window_shape_prev];
 109     window_short      = fb->short_window[window_shape];
 110     window_short_prev = fb->short_window[window_shape_prev];
 111
 112     switch (window_sequence)
 113     {
 114     case ONLY_LONG_SEQUENCE:
 115         imdct_ssr(fb, freq_in, transf_buf, 2*nlong);
 116         for (i = nlong-1; i >= 0; i--)
 117         {
 118             time_out[i] = MUL_R_C(transf_buf[i],window_long_prev[i]);
 119             time_out[nlong+i] = MUL_R_C(transf_buf[nlong+i],window_long[nlong-1-i]);
 120         }
 121         break;
 122
 123     case LONG_START_SEQUENCE:
 124         imdct_ssr(fb, freq_in, transf_buf, 2*nlong);
 125         for (i = 0; i < nlong; i++)
 126             time_out[i] = MUL_R_C(transf_buf[i],window_long_prev[i]);
 127         for (i = 0; i < nflat_ls; i++)
 128             time_out[nlong+i] = transf_buf[nlong+i];
 129         for (i = 0; i < nshort; i++)
 130             time_out[nlong+nflat_ls+i] = MUL_R_C(transf_buf[nlong+nflat_ls+i],window_short[nshort-i-1]);
 131         for (i = 0; i < nflat_ls; i++)
 132             time_out[nlong+nflat_ls+nshort+i] = 0;
 133         break;
 134
 135     case EIGHT_SHORT_SEQUENCE:
 136         imdct_ssr(fb, freq_in+0*nshort, transf_buf+2*nshort*0, 2*nshort);
 137         imdct_ssr(fb, freq_in+1*nshort, transf_buf+2*nshort*1, 2*nshort);
 138         imdct_ssr(fb, freq_in+2*nshort, transf_buf+2*nshort*2, 2*nshort);
 139         imdct_ssr(fb, freq_in+3*nshort, transf_buf+2*nshort*3, 2*nshort);
 140         imdct_ssr(fb, freq_in+4*nshort, transf_buf+2*nshort*4, 2*nshort);
 141         imdct_ssr(fb, freq_in+5*nshort, transf_buf+2*nshort*5, 2*nshort);
 142         imdct_ssr(fb, freq_in+6*nshort, transf_buf+2*nshort*6, 2*nshort);
 143         imdct_ssr(fb, freq_in+7*nshort, transf_buf+2*nshort*7, 2*nshort);
 144         for(i = nshort-1; i >= 0; i--)
 145         {
 146             time_out[i+0*nshort] = MUL_R_C(transf_buf[nshort*0+i],window_short_prev[i]);
 147             time_out[i+1*nshort] = MUL_R_C(transf_buf[nshort*1+i],window_short[i]);
 148             time_out[i+2*nshort] = MUL_R_C(transf_buf[nshort*2+i],window_short_prev[i]);
 149             time_out[i+3*nshort] = MUL_R_C(transf_buf[nshort*3+i],window_short[i]);
 150             time_out[i+4*nshort] = MUL_R_C(transf_buf[nshort*4+i],window_short_prev[i]);
 151             time_out[i+5*nshort] = MUL_R_C(transf_buf[nshort*5+i],window_short[i]);
 152             time_out[i+6*nshort] = MUL_R_C(transf_buf[nshort*6+i],window_short_prev[i]);
 153             time_out[i+7*nshort] = MUL_R_C(transf_buf[nshort*7+i],window_short[i]);
 154             time_out[i+8*nshort] = MUL_R_C(transf_buf[nshort*8+i],window_short_prev[i]);
 155             time_out[i+9*nshort] = MUL_R_C(transf_buf[nshort*9+i],window_short[i]);
 156             time_out[i+10*nshort] = MUL_R_C(transf_buf[nshort*10+i],window_short_prev[i]);
 157             time_out[i+11*nshort] = MUL_R_C(transf_buf[nshort*11+i],window_short[i]);
 158             time_out[i+12*nshort] = MUL_R_C(transf_buf[nshort*12+i],window_short_prev[i]);
 159             time_out[i+13*nshort] = MUL_R_C(transf_buf[nshort*13+i],window_short[i]);
 160             time_out[i+14*nshort] = MUL_R_C(transf_buf[nshort*14+i],window_short_prev[i]);
 161             time_out[i+15*nshort] = MUL_R_C(transf_buf[nshort*15+i],window_short[i]);
 162         }
 163         break;
 164
 165     case LONG_STOP_SEQUENCE:
 166         imdct_ssr(fb, freq_in, transf_buf, 2*nlong);
 167         for (i = 0; i < nflat_ls; i++)
 168             time_out[i] = 0;
 169         for (i = 0; i < nshort; i++)
 170             time_out[nflat_ls+i] = MUL_R_C(transf_buf[nflat_ls+i],window_short_prev[i]);
 171         for (i = 0; i < nflat_ls; i++)
 172             time_out[nflat_ls+nshort+i] = transf_buf[nflat_ls+nshort+i];
 173         for (i = 0; i < nlong; i++)
 174             time_out[nlong+i] = MUL_R_C(transf_buf[nlong+i],window_long[nlong-1-i]);
 175                 break;
 176     }
 177
 178     faad_free(transf_buf);
 179 }
 180
 181
 182 #endif