git.sesse.net Git - vlc/blob - plugins/ac3_adec/ac3_imdct.c

   1 /*****************************************************************************
   2  * ac3_imdct.c: ac3 DCT
   3  *****************************************************************************
   4  * Copyright (C) 1999-2001 VideoLAN
   5  * $Id: ac3_imdct.c,v 1.9 2002/06/01 12:31:58 sam Exp $
   6  *
   7  * Authors: Michel Kaempf <maxx@via.ecp.fr>
   8  *          Aaron Holtzman <aholtzma@engr.uvic.ca>
   9  *          Renaud Dartus <reno@videolan.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  24  *****************************************************************************/
  25
  26 /*****************************************************************************
  27  * Preamble
  28  *****************************************************************************/
  29 #include <string.h>                                              /* memcpy() */
  30
  31 #include <math.h>
  32 #include <stdio.h>
  33
  34 #include <vlc/vlc.h>
  35 #include <vlc/decoder.h>
  36
  37 #include "ac3_imdct.h"
  38 #include "ac3_downmix.h"
  39 #include "ac3_adec.h"
  40
  41 #ifndef M_PI
  42 #   define M_PI 3.14159265358979323846
  43 #endif
  44
  45 void _M( imdct_init )(imdct_t * p_imdct)
  46 {
  47     int i;
  48     float scale = 181.019;
  49
  50     p_imdct->pf_imdct_init( p_imdct );
  51
  52     /* More twiddle factors to turn IFFT into IMDCT */
  53     for (i=0; i < 64; i++) {
  54         p_imdct->xcos2[i] = cos(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  55         p_imdct->xsin2[i] = sin(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  56     }
  57 }
  58
  59 void imdct (ac3dec_t * p_ac3dec, s16 * buffer)
  60 {
  61     int   i;
  62     int   doable = 0;
  63     float *center=NULL, *left, *right, *left_sur, *right_sur;
  64     float *delay_left, *delay_right;
  65     float *delay1_left, *delay1_right, *delay1_center, *delay1_sr, *delay1_sl;
  66     float right_tmp, left_tmp;
  67     void (*do_imdct)(imdct_t * p_imdct, float data[], float delay[]);
  68
  69     /* test if dm in frequency is doable */
  70     if (!(doable = p_ac3dec->audblk.blksw[0]))
  71     {
  72         do_imdct = p_ac3dec->imdct->pf_imdct_512;
  73     }
  74     else
  75     {
  76         do_imdct = p_ac3dec->imdct->pf_imdct_256;
  77     }
  78
  79     /* downmix in the frequency domain if all the channels
  80      * use the same imdct */
  81     for (i=0; i < p_ac3dec->bsi.nfchans; i++)
  82     {
  83         if (doable != p_ac3dec->audblk.blksw[i])
  84         {
  85             do_imdct = NULL;
  86             break;
  87         }
  88     }
  89
  90     if (do_imdct)
  91     {
  92         /* dowmix first and imdct */
  93         switch(p_ac3dec->bsi.acmod)
  94         {
  95             case 7:        /* 3/2 */
  96                 p_ac3dec->downmix.pf_downmix_3f_2r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
  97                 break;
  98             case 6:        /* 2/2 */
  99                 p_ac3dec->downmix.pf_downmix_2f_2r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 100                 break;
 101             case 5:        /* 3/1 */
 102                 p_ac3dec->downmix.pf_downmix_3f_1r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 103                 break;
 104             case 4:        /* 2/1 */
 105                 p_ac3dec->downmix.pf_downmix_2f_1r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 106                 break;
 107             case 3:        /* 3/0 */
 108                 p_ac3dec->downmix.pf_downmix_3f_0r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 109                 break;
 110             case 2:
 111                 break;
 112             default:    /* 1/0 */
 113 //                if (p_ac3dec->bsi.acmod == 1)
 114                     center = p_ac3dec->samples;
 115 //                else if (p_ac3dec->bsi.acmod == 0)
 116 //                  center = samples[ac3_config.dual_mono_ch_sel];
 117                 do_imdct(p_ac3dec->imdct, center, p_ac3dec->imdct->delay); /* no downmix*/
 118
 119                 p_ac3dec->downmix.pf_stream_sample_1ch_to_s16 (buffer, center);
 120
 121                 return;
 122                 break;
 123         }
 124
 125         do_imdct (p_ac3dec->imdct, p_ac3dec->samples, p_ac3dec->imdct->delay);
 126         do_imdct (p_ac3dec->imdct, p_ac3dec->samples+256, p_ac3dec->imdct->delay+256);
 127         p_ac3dec->downmix.pf_stream_sample_2ch_to_s16(buffer, p_ac3dec->samples, p_ac3dec->samples+256);
 128
 129     } else {
 130         /* imdct and then downmix
 131          * delay and samples should be saved and mixed
 132          * fprintf(stderr, "time domain downmix\n"); */
 133         for (i=0; i<p_ac3dec->bsi.nfchans; i++)
 134         {
 135             if (p_ac3dec->audblk.blksw[i])
 136             {
 137                 /* There is only a C function */
 138                 p_ac3dec->imdct->pf_imdct_256_nol( p_ac3dec->imdct,
 139                      p_ac3dec->samples+256*i, p_ac3dec->imdct->delay1+256*i );
 140             }
 141             else
 142             {
 143                 p_ac3dec->imdct->pf_imdct_512_nol( p_ac3dec->imdct,
 144                      p_ac3dec->samples+256*i, p_ac3dec->imdct->delay1+256*i );
 145             }
 146         }
 147
 148         /* mix the sample, overlap */
 149         switch(p_ac3dec->bsi.acmod)
 150         {
 151             case 7:        /* 3/2 */
 152                 left = p_ac3dec->samples;
 153                 center = p_ac3dec->samples+256;
 154                 right = p_ac3dec->samples+2*256;
 155                 left_sur = p_ac3dec->samples+3*256;
 156                 right_sur = p_ac3dec->samples+4*256;
 157                 delay_left = p_ac3dec->imdct->delay;
 158                 delay_right = p_ac3dec->imdct->delay+256;
 159                 delay1_left = p_ac3dec->imdct->delay1;
 160                 delay1_center = p_ac3dec->imdct->delay1+256;
 161                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 162                 delay1_sl = p_ac3dec->imdct->delay1+3*256;
 163                 delay1_sr = p_ac3dec->imdct->delay1+4*256;
 164
 165                 for (i = 0; i < 256; i++) {
 166                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  + p_ac3dec->dm_par.slev * *left_sur++;
 167                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 168                     *buffer++ = (s16)(left_tmp + *delay_left);
 169                     *buffer++ = (s16)(right_tmp + *delay_right);
 170                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl++;
 171                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 172                 }
 173                 break;
 174             case 6:        /* 2/2 */
 175                 left = p_ac3dec->samples;
 176                 right = p_ac3dec->samples+256;
 177                 left_sur = p_ac3dec->samples+2*256;
 178                 right_sur = p_ac3dec->samples+3*256;
 179                 delay_left = p_ac3dec->imdct->delay;
 180                 delay_right = p_ac3dec->imdct->delay+256;
 181                 delay1_left = p_ac3dec->imdct->delay1;
 182                 delay1_right = p_ac3dec->imdct->delay1+256;
 183                 delay1_sl = p_ac3dec->imdct->delay1+2*256;
 184                 delay1_sr = p_ac3dec->imdct->delay1+3*256;
 185
 186                 for (i = 0; i < 256; i++) {
 187                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.slev * *left_sur++;
 188                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 189                     *buffer++ = (s16)(left_tmp + *delay_left);
 190                     *buffer++ = (s16)(right_tmp + *delay_right);
 191                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.slev * *delay1_sl++;
 192                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 193                 }
 194                 break;
 195             case 5:        /* 3/1 */
 196                 left = p_ac3dec->samples;
 197                 center = p_ac3dec->samples+256;
 198                 right = p_ac3dec->samples+2*256;
 199                 right_sur = p_ac3dec->samples+3*256;
 200                 delay_left = p_ac3dec->imdct->delay;
 201                 delay_right = p_ac3dec->imdct->delay+256;
 202                 delay1_left = p_ac3dec->imdct->delay1;
 203                 delay1_center = p_ac3dec->imdct->delay1+256;
 204                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 205                 delay1_sl = p_ac3dec->imdct->delay1+3*256;
 206
 207                 for (i = 0; i < 256; i++) {
 208                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  - p_ac3dec->dm_par.slev * *right_sur;
 209                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 210                     *buffer++ = (s16)(left_tmp + *delay_left);
 211                     *buffer++ = (s16)(right_tmp + *delay_right);
 212                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl;
 213                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 214                 }
 215                 break;
 216             case 4:        /* 2/1 */
 217                 left = p_ac3dec->samples;
 218                 right = p_ac3dec->samples+256;
 219                 right_sur = p_ac3dec->samples+2*256;
 220                 delay_left = p_ac3dec->imdct->delay;
 221                 delay_right = p_ac3dec->imdct->delay+256;
 222                 delay1_left = p_ac3dec->imdct->delay1;
 223                 delay1_right = p_ac3dec->imdct->delay1+256;
 224                 delay1_sl = p_ac3dec->imdct->delay1+2*256;
 225
 226                 for (i = 0; i < 256; i++) {
 227                     left_tmp = p_ac3dec->dm_par.unit * *left++ - p_ac3dec->dm_par.slev * *right_sur;
 228                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 229                     *buffer++ = (s16)(left_tmp + *delay_left);
 230                     *buffer++ = (s16)(right_tmp + *delay_right);
 231                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++ + p_ac3dec->dm_par.slev * *delay1_sl;
 232                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 233                 }
 234                 break;
 235             case 3:        /* 3/0 */
 236                 left = p_ac3dec->samples;
 237                 center = p_ac3dec->samples+256;
 238                 right = p_ac3dec->samples+2*256;
 239                 delay_left = p_ac3dec->imdct->delay;
 240                 delay_right = p_ac3dec->imdct->delay+256;
 241                 delay1_left = p_ac3dec->imdct->delay1;
 242                 delay1_center = p_ac3dec->imdct->delay1+256;
 243                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 244
 245                 for (i = 0; i < 256; i++) {
 246                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center;
 247                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++;
 248                     *buffer++ = (s16)(left_tmp + *delay_left);
 249                     *buffer++ = (s16)(right_tmp + *delay_right);
 250                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center;
 251                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++;
 252                 }
 253                 break;
 254             case 2:        /* copy to output */
 255                 for (i = 0; i < 256; i++) {
 256                     *buffer++ = (s16) *(p_ac3dec->samples+i);
 257                     *buffer++ = (s16) *(p_ac3dec->samples+256+i);
 258                 }
 259                 break;
 260         }
 261     }
 262 }