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 1.5 2001/12/09 17:01:36 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 "defs.h"
  30
  31 #include <string.h>                                              /* memcpy() */
  32
  33 #include <math.h>
  34 #include <stdio.h>
  35
  36 #include "common.h"
  37 #include "intf_msg.h"
  38 #include "threads.h"
  39 #include "mtime.h"
  40
  41 #include "modules.h"
  42 #include "modules_export.h"
  43
  44 #include "stream_control.h"
  45 #include "input_ext-dec.h"
  46
  47 #include "ac3_imdct.h"
  48 #include "ac3_downmix.h"
  49 #include "ac3_decoder.h"
  50
  51 #ifndef M_PI
  52 #   define M_PI 3.14159265358979323846
  53 #endif
  54
  55 void imdct_init(imdct_t * p_imdct)
  56 {
  57     int i;
  58     float scale = 181.019;
  59
  60     p_imdct->pf_imdct_init( p_imdct );
  61
  62     /* More twiddle factors to turn IFFT into IMDCT */
  63     for (i=0; i < 64; i++) {
  64         p_imdct->xcos2[i] = cos(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  65         p_imdct->xsin2[i] = sin(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  66     }
  67 }
  68
  69 void imdct (ac3dec_t * p_ac3dec, s16 * buffer)
  70 {
  71     int   i;
  72     int   doable = 0;
  73     float *center=NULL, *left, *right, *left_sur, *right_sur;
  74     float *delay_left, *delay_right;
  75     float *delay1_left, *delay1_right, *delay1_center, *delay1_sr, *delay1_sl;
  76     float right_tmp, left_tmp;
  77     void (*do_imdct)(imdct_t * p_imdct, float data[], float delay[]);
  78
  79     /* test if dm in frequency is doable */
  80     if (!(doable = p_ac3dec->audblk.blksw[0]))
  81     {
  82         do_imdct = p_ac3dec->imdct->pf_imdct_512;
  83     }
  84     else
  85     {
  86         do_imdct = p_ac3dec->imdct->pf_imdct_256;
  87     }
  88
  89     /* downmix in the frequency domain if all the channels
  90      * use the same imdct */
  91     for (i=0; i < p_ac3dec->bsi.nfchans; i++)
  92     {
  93         if (doable != p_ac3dec->audblk.blksw[i])
  94         {
  95             do_imdct = NULL;
  96             break;
  97         }
  98     }
  99
 100     if (do_imdct)
 101     {
 102         /* dowmix first and imdct */
 103         switch(p_ac3dec->bsi.acmod)
 104         {
 105             case 7:        /* 3/2 */
 106                 p_ac3dec->downmix.pf_downmix_3f_2r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 107                 break;
 108             case 6:        /* 2/2 */
 109                 p_ac3dec->downmix.pf_downmix_2f_2r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 110                 break;
 111             case 5:        /* 3/1 */
 112                 p_ac3dec->downmix.pf_downmix_3f_1r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 113                 break;
 114             case 4:        /* 2/1 */
 115                 p_ac3dec->downmix.pf_downmix_2f_1r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 116                 break;
 117             case 3:        /* 3/0 */
 118                 p_ac3dec->downmix.pf_downmix_3f_0r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 119                 break;
 120             case 2:
 121                 break;
 122             default:    /* 1/0 */
 123 //                if (p_ac3dec->bsi.acmod == 1)
 124                     center = p_ac3dec->samples;
 125 //                else if (p_ac3dec->bsi.acmod == 0)
 126 //                  center = samples[ac3_config.dual_mono_ch_sel];
 127                 do_imdct(p_ac3dec->imdct, center, p_ac3dec->imdct->delay); /* no downmix*/
 128
 129                 p_ac3dec->downmix.pf_stream_sample_1ch_to_s16 (buffer, center);
 130
 131                 return;
 132                 break;
 133         }
 134
 135         do_imdct (p_ac3dec->imdct, p_ac3dec->samples, p_ac3dec->imdct->delay);
 136         do_imdct (p_ac3dec->imdct, p_ac3dec->samples+256, p_ac3dec->imdct->delay+256);
 137         p_ac3dec->downmix.pf_stream_sample_2ch_to_s16(buffer, p_ac3dec->samples, p_ac3dec->samples+256);
 138
 139     } else {
 140         /* imdct and then downmix
 141          * delay and samples should be saved and mixed
 142          * fprintf(stderr, "time domain downmix\n"); */
 143         for (i=0; i<p_ac3dec->bsi.nfchans; i++)
 144         {
 145             if (p_ac3dec->audblk.blksw[i])
 146             {
 147                 /* There is only a C function */
 148                 p_ac3dec->imdct->pf_imdct_256_nol( p_ac3dec->imdct,
 149                      p_ac3dec->samples+256*i, p_ac3dec->imdct->delay1+256*i );
 150             }
 151             else
 152             {
 153                 p_ac3dec->imdct->pf_imdct_512_nol( p_ac3dec->imdct,
 154                      p_ac3dec->samples+256*i, p_ac3dec->imdct->delay1+256*i );
 155             }
 156         }
 157
 158         /* mix the sample, overlap */
 159         switch(p_ac3dec->bsi.acmod)
 160         {
 161             case 7:        /* 3/2 */
 162                 left = p_ac3dec->samples;
 163                 center = p_ac3dec->samples+256;
 164                 right = p_ac3dec->samples+2*256;
 165                 left_sur = p_ac3dec->samples+3*256;
 166                 right_sur = p_ac3dec->samples+4*256;
 167                 delay_left = p_ac3dec->imdct->delay;
 168                 delay_right = p_ac3dec->imdct->delay+256;
 169                 delay1_left = p_ac3dec->imdct->delay1;
 170                 delay1_center = p_ac3dec->imdct->delay1+256;
 171                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 172                 delay1_sl = p_ac3dec->imdct->delay1+3*256;
 173                 delay1_sr = p_ac3dec->imdct->delay1+4*256;
 174
 175                 for (i = 0; i < 256; i++) {
 176                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  + p_ac3dec->dm_par.slev * *left_sur++;
 177                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 178                     *buffer++ = (s16)(left_tmp + *delay_left);
 179                     *buffer++ = (s16)(right_tmp + *delay_right);
 180                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl++;
 181                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 182                 }
 183                 break;
 184             case 6:        /* 2/2 */
 185                 left = p_ac3dec->samples;
 186                 right = p_ac3dec->samples+256;
 187                 left_sur = p_ac3dec->samples+2*256;
 188                 right_sur = p_ac3dec->samples+3*256;
 189                 delay_left = p_ac3dec->imdct->delay;
 190                 delay_right = p_ac3dec->imdct->delay+256;
 191                 delay1_left = p_ac3dec->imdct->delay1;
 192                 delay1_right = p_ac3dec->imdct->delay1+256;
 193                 delay1_sl = p_ac3dec->imdct->delay1+2*256;
 194                 delay1_sr = p_ac3dec->imdct->delay1+3*256;
 195
 196                 for (i = 0; i < 256; i++) {
 197                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.slev * *left_sur++;
 198                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 199                     *buffer++ = (s16)(left_tmp + *delay_left);
 200                     *buffer++ = (s16)(right_tmp + *delay_right);
 201                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.slev * *delay1_sl++;
 202                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 203                 }
 204                 break;
 205             case 5:        /* 3/1 */
 206                 left = p_ac3dec->samples;
 207                 center = p_ac3dec->samples+256;
 208                 right = p_ac3dec->samples+2*256;
 209                 right_sur = p_ac3dec->samples+3*256;
 210                 delay_left = p_ac3dec->imdct->delay;
 211                 delay_right = p_ac3dec->imdct->delay+256;
 212                 delay1_left = p_ac3dec->imdct->delay1;
 213                 delay1_center = p_ac3dec->imdct->delay1+256;
 214                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 215                 delay1_sl = p_ac3dec->imdct->delay1+3*256;
 216
 217                 for (i = 0; i < 256; i++) {
 218                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  - p_ac3dec->dm_par.slev * *right_sur;
 219                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 220                     *buffer++ = (s16)(left_tmp + *delay_left);
 221                     *buffer++ = (s16)(right_tmp + *delay_right);
 222                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl;
 223                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 224                 }
 225                 break;
 226             case 4:        /* 2/1 */
 227                 left = p_ac3dec->samples;
 228                 right = p_ac3dec->samples+256;
 229                 right_sur = p_ac3dec->samples+2*256;
 230                 delay_left = p_ac3dec->imdct->delay;
 231                 delay_right = p_ac3dec->imdct->delay+256;
 232                 delay1_left = p_ac3dec->imdct->delay1;
 233                 delay1_right = p_ac3dec->imdct->delay1+256;
 234                 delay1_sl = p_ac3dec->imdct->delay1+2*256;
 235
 236                 for (i = 0; i < 256; i++) {
 237                     left_tmp = p_ac3dec->dm_par.unit * *left++ - p_ac3dec->dm_par.slev * *right_sur;
 238                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 239                     *buffer++ = (s16)(left_tmp + *delay_left);
 240                     *buffer++ = (s16)(right_tmp + *delay_right);
 241                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++ + p_ac3dec->dm_par.slev * *delay1_sl;
 242                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 243                 }
 244                 break;
 245             case 3:        /* 3/0 */
 246                 left = p_ac3dec->samples;
 247                 center = p_ac3dec->samples+256;
 248                 right = p_ac3dec->samples+2*256;
 249                 delay_left = p_ac3dec->imdct->delay;
 250                 delay_right = p_ac3dec->imdct->delay+256;
 251                 delay1_left = p_ac3dec->imdct->delay1;
 252                 delay1_center = p_ac3dec->imdct->delay1+256;
 253                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 254
 255                 for (i = 0; i < 256; i++) {
 256                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center;
 257                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++;
 258                     *buffer++ = (s16)(left_tmp + *delay_left);
 259                     *buffer++ = (s16)(right_tmp + *delay_right);
 260                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center;
 261                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++;
 262                 }
 263                 break;
 264             case 2:        /* copy to output */
 265                 for (i = 0; i < 256; i++) {
 266                     *buffer++ = (s16) *(p_ac3dec->samples+i);
 267                     *buffer++ = (s16) *(p_ac3dec->samples+256+i);
 268                 }
 269                 break;
 270         }
 271     }
 272 }