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 1.4 2001/11/28 15:08:04 massiot 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 "defs.h"
  30
  31 #include <string.h>                                              /* memcpy() */
  32
  33 #include <math.h>
  34 #include <stdio.h>
  35
  36 #include "config.h"
  37 #include "common.h"
  38 #include "intf_msg.h"
  39 #include "threads.h"
  40 #include "mtime.h"
  41
  42 #include "modules.h"
  43 #include "modules_export.h"
  44
  45 #include "stream_control.h"
  46 #include "input_ext-dec.h"
  47
  48 #include "ac3_imdct.h"
  49 #include "ac3_downmix.h"
  50 #include "ac3_decoder.h"
  51
  52 #ifndef M_PI
  53 #   define M_PI 3.14159265358979323846
  54 #endif
  55
  56 void imdct_init(imdct_t * p_imdct)
  57 {
  58     int i;
  59     float scale = 181.019;
  60
  61     p_imdct->pf_imdct_init( p_imdct );
  62
  63     /* More twiddle factors to turn IFFT into IMDCT */
  64     for (i=0; i < 64; i++) {
  65         p_imdct->xcos2[i] = cos(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  66         p_imdct->xsin2[i] = sin(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  67     }
  68 }
  69
  70 void imdct (ac3dec_t * p_ac3dec, s16 * buffer)
  71 {
  72     int   i;
  73     int   doable = 0;
  74     float *center=NULL, *left, *right, *left_sur, *right_sur;
  75     float *delay_left, *delay_right;
  76     float *delay1_left, *delay1_right, *delay1_center, *delay1_sr, *delay1_sl;
  77     float right_tmp, left_tmp;
  78     void (*do_imdct)(imdct_t * p_imdct, float data[], float delay[]);
  79
  80     /* test if dm in frequency is doable */
  81     if (!(doable = p_ac3dec->audblk.blksw[0]))
  82     {
  83         do_imdct = p_ac3dec->imdct->pf_imdct_512;
  84     }
  85     else
  86     {
  87         do_imdct = p_ac3dec->imdct->pf_imdct_256;
  88     }
  89
  90     /* downmix in the frequency domain if all the channels
  91      * use the same imdct */
  92     for (i=0; i < p_ac3dec->bsi.nfchans; i++)
  93     {
  94         if (doable != p_ac3dec->audblk.blksw[i])
  95         {
  96             do_imdct = NULL;
  97             break;
  98         }
  99     }
 100
 101     if (do_imdct)
 102     {
 103         /* dowmix first and imdct */
 104         switch(p_ac3dec->bsi.acmod)
 105         {
 106             case 7:        /* 3/2 */
 107                 p_ac3dec->downmix.pf_downmix_3f_2r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 108                 break;
 109             case 6:        /* 2/2 */
 110                 p_ac3dec->downmix.pf_downmix_2f_2r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 111                 break;
 112             case 5:        /* 3/1 */
 113                 p_ac3dec->downmix.pf_downmix_3f_1r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 114                 break;
 115             case 4:        /* 2/1 */
 116                 p_ac3dec->downmix.pf_downmix_2f_1r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 117                 break;
 118             case 3:        /* 3/0 */
 119                 p_ac3dec->downmix.pf_downmix_3f_0r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 120                 break;
 121             case 2:
 122                 break;
 123             default:    /* 1/0 */
 124 //                if (p_ac3dec->bsi.acmod == 1)
 125                     center = p_ac3dec->samples;
 126 //                else if (p_ac3dec->bsi.acmod == 0)
 127 //                  center = samples[ac3_config.dual_mono_ch_sel];
 128                 do_imdct(p_ac3dec->imdct, center, p_ac3dec->imdct->delay); /* no downmix*/
 129
 130                 p_ac3dec->downmix.pf_stream_sample_1ch_to_s16 (buffer, center);
 131
 132                 return;
 133                 break;
 134         }
 135
 136         do_imdct (p_ac3dec->imdct, p_ac3dec->samples, p_ac3dec->imdct->delay);
 137         do_imdct (p_ac3dec->imdct, p_ac3dec->samples+256, p_ac3dec->imdct->delay+256);
 138         p_ac3dec->downmix.pf_stream_sample_2ch_to_s16(buffer, p_ac3dec->samples, p_ac3dec->samples+256);
 139
 140     } else {
 141         /* imdct and then downmix
 142          * delay and samples should be saved and mixed
 143          * fprintf(stderr, "time domain downmix\n"); */
 144         for (i=0; i<p_ac3dec->bsi.nfchans; i++)
 145         {
 146             if (p_ac3dec->audblk.blksw[i])
 147             {
 148                 /* There is only a C function */
 149                 p_ac3dec->imdct->pf_imdct_256_nol( p_ac3dec->imdct,
 150                      p_ac3dec->samples+256*i, p_ac3dec->imdct->delay1+256*i );
 151             }
 152             else
 153             {
 154                 p_ac3dec->imdct->pf_imdct_512_nol( p_ac3dec->imdct,
 155                      p_ac3dec->samples+256*i, p_ac3dec->imdct->delay1+256*i );
 156             }
 157         }
 158
 159         /* mix the sample, overlap */
 160         switch(p_ac3dec->bsi.acmod)
 161         {
 162             case 7:        /* 3/2 */
 163                 left = p_ac3dec->samples;
 164                 center = p_ac3dec->samples+256;
 165                 right = p_ac3dec->samples+2*256;
 166                 left_sur = p_ac3dec->samples+3*256;
 167                 right_sur = p_ac3dec->samples+4*256;
 168                 delay_left = p_ac3dec->imdct->delay;
 169                 delay_right = p_ac3dec->imdct->delay+256;
 170                 delay1_left = p_ac3dec->imdct->delay1;
 171                 delay1_center = p_ac3dec->imdct->delay1+256;
 172                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 173                 delay1_sl = p_ac3dec->imdct->delay1+3*256;
 174                 delay1_sr = p_ac3dec->imdct->delay1+4*256;
 175
 176                 for (i = 0; i < 256; i++) {
 177                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  + p_ac3dec->dm_par.slev * *left_sur++;
 178                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 179                     *buffer++ = (s16)(left_tmp + *delay_left);
 180                     *buffer++ = (s16)(right_tmp + *delay_right);
 181                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl++;
 182                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 183                 }
 184                 break;
 185             case 6:        /* 2/2 */
 186                 left = p_ac3dec->samples;
 187                 right = p_ac3dec->samples+256;
 188                 left_sur = p_ac3dec->samples+2*256;
 189                 right_sur = p_ac3dec->samples+3*256;
 190                 delay_left = p_ac3dec->imdct->delay;
 191                 delay_right = p_ac3dec->imdct->delay+256;
 192                 delay1_left = p_ac3dec->imdct->delay1;
 193                 delay1_right = p_ac3dec->imdct->delay1+256;
 194                 delay1_sl = p_ac3dec->imdct->delay1+2*256;
 195                 delay1_sr = p_ac3dec->imdct->delay1+3*256;
 196
 197                 for (i = 0; i < 256; i++) {
 198                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.slev * *left_sur++;
 199                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 200                     *buffer++ = (s16)(left_tmp + *delay_left);
 201                     *buffer++ = (s16)(right_tmp + *delay_right);
 202                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.slev * *delay1_sl++;
 203                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 204                 }
 205                 break;
 206             case 5:        /* 3/1 */
 207                 left = p_ac3dec->samples;
 208                 center = p_ac3dec->samples+256;
 209                 right = p_ac3dec->samples+2*256;
 210                 right_sur = p_ac3dec->samples+3*256;
 211                 delay_left = p_ac3dec->imdct->delay;
 212                 delay_right = p_ac3dec->imdct->delay+256;
 213                 delay1_left = p_ac3dec->imdct->delay1;
 214                 delay1_center = p_ac3dec->imdct->delay1+256;
 215                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 216                 delay1_sl = p_ac3dec->imdct->delay1+3*256;
 217
 218                 for (i = 0; i < 256; i++) {
 219                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  - p_ac3dec->dm_par.slev * *right_sur;
 220                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 221                     *buffer++ = (s16)(left_tmp + *delay_left);
 222                     *buffer++ = (s16)(right_tmp + *delay_right);
 223                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl;
 224                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 225                 }
 226                 break;
 227             case 4:        /* 2/1 */
 228                 left = p_ac3dec->samples;
 229                 right = p_ac3dec->samples+256;
 230                 right_sur = p_ac3dec->samples+2*256;
 231                 delay_left = p_ac3dec->imdct->delay;
 232                 delay_right = p_ac3dec->imdct->delay+256;
 233                 delay1_left = p_ac3dec->imdct->delay1;
 234                 delay1_right = p_ac3dec->imdct->delay1+256;
 235                 delay1_sl = p_ac3dec->imdct->delay1+2*256;
 236
 237                 for (i = 0; i < 256; i++) {
 238                     left_tmp = p_ac3dec->dm_par.unit * *left++ - p_ac3dec->dm_par.slev * *right_sur;
 239                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 240                     *buffer++ = (s16)(left_tmp + *delay_left);
 241                     *buffer++ = (s16)(right_tmp + *delay_right);
 242                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++ + p_ac3dec->dm_par.slev * *delay1_sl;
 243                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 244                 }
 245                 break;
 246             case 3:        /* 3/0 */
 247                 left = p_ac3dec->samples;
 248                 center = p_ac3dec->samples+256;
 249                 right = p_ac3dec->samples+2*256;
 250                 delay_left = p_ac3dec->imdct->delay;
 251                 delay_right = p_ac3dec->imdct->delay+256;
 252                 delay1_left = p_ac3dec->imdct->delay1;
 253                 delay1_center = p_ac3dec->imdct->delay1+256;
 254                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 255
 256                 for (i = 0; i < 256; i++) {
 257                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center;
 258                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++;
 259                     *buffer++ = (s16)(left_tmp + *delay_left);
 260                     *buffer++ = (s16)(right_tmp + *delay_right);
 261                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center;
 262                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++;
 263                 }
 264                 break;
 265             case 2:        /* copy to output */
 266                 for (i = 0; i < 256; i++) {
 267                     *buffer++ = (s16) *(p_ac3dec->samples+i);
 268                     *buffer++ = (s16) *(p_ac3dec->samples+256+i);
 269                 }
 270                 break;
 271         }
 272     }
 273 }