git.sesse.net Git - vlc/blob - src/ac3_decoder/ac3_imdct.c

   1 /*****************************************************************************
   2  * ac3_imdct.c: ac3 DCT
   3  *****************************************************************************
   4  * Copyright (C) 1999, 2000 VideoLAN
   5  * $Id: ac3_imdct.c,v 1.18 2001/05/06 04:32:02 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 #include "defs.h"
  27
  28 #include <string.h>                                              /* memcpy() */
  29
  30 #include <math.h>
  31 #include <stdio.h>
  32
  33 #include "config.h"
  34 #include "common.h"
  35 #include "threads.h"
  36 #include "mtime.h"
  37
  38 #include "stream_control.h"
  39 #include "input_ext-dec.h"
  40
  41 #include "ac3_decoder.h"
  42 #include "ac3_internal.h"
  43
  44 #include "ac3_downmix.h"
  45 #include "ac3_imdct_c.h"
  46 #if 0
  47 #include "ac3_imdct_kni.h"
  48 #endif
  49
  50 #include "tests.h"
  51
  52 #ifndef M_PI
  53 #   define M_PI 3.14159265358979323846
  54 #endif
  55
  56
  57 void imdct_init(imdct_t * p_imdct)
  58 {
  59         int i;
  60         float scale = 255.99609372;
  61
  62 #if 0
  63         if ( TestCPU (CPU_CAPABILITY_MMX) )
  64     {
  65         imdct_init_kni (p_imdct);
  66     } else
  67 #endif
  68     {
  69         imdct_init_c (p_imdct);
  70     }
  71
  72         /* More twiddle factors to turn IFFT into IMDCT */
  73         for (i=0; i < 64; i++) {
  74                 p_imdct->xcos2[i] = cos(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  75                 p_imdct->xsin2[i] = sin(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  76         }
  77 }
  78
  79 void imdct (ac3dec_t * p_ac3dec, s16 * buffer)
  80 {
  81         int   i;
  82         int   doable = 0;
  83         float *center=NULL, *left, *right, *left_sur, *right_sur;
  84         float *delay_left, *delay_right;
  85         float *delay1_left, *delay1_right, *delay1_center, *delay1_sr, *delay1_sl;
  86         float right_tmp, left_tmp;
  87         void (*do_imdct)(imdct_t * p_imdct, float data[], float delay[]);
  88
  89         /* test if dm in frequency is doable */
  90         if (!(doable = p_ac3dec->audblk.blksw[0]))
  91     {
  92                 do_imdct = p_ac3dec->imdct.imdct_do_512;
  93     }
  94         else
  95     {
  96                 do_imdct = imdct_do_256; /* There is only a C function */
  97     }
  98
  99         /* downmix in the frequency domain if all the channels
 100          * use the same imdct */
 101         for (i=0; i < p_ac3dec->bsi.nfchans; i++)
 102     {
 103                 if (doable != p_ac3dec->audblk.blksw[i])
 104         {
 105                         do_imdct = NULL;
 106                         break;
 107                 }
 108         }
 109
 110     if (do_imdct)
 111     {
 112                 /* dowmix first and imdct */
 113         switch(p_ac3dec->bsi.acmod)
 114         {
 115                 case 7:         /* 3/2 */
 116                         p_ac3dec->downmix.downmix_3f_2r_to_2ch (p_ac3dec->samples[0], &p_ac3dec->dm_par);
 117                         break;
 118                 case 6:         /* 2/2 */
 119                         p_ac3dec->downmix.downmix_2f_2r_to_2ch (p_ac3dec->samples[0], &p_ac3dec->dm_par);
 120                         break;
 121                 case 5:         /* 3/1 */
 122                         p_ac3dec->downmix.downmix_3f_1r_to_2ch (p_ac3dec->samples[0], &p_ac3dec->dm_par);
 123                         break;
 124                 case 4:         /* 2/1 */
 125                         p_ac3dec->downmix.downmix_2f_1r_to_2ch (p_ac3dec->samples[0], &p_ac3dec->dm_par);
 126                         break;
 127                 case 3:         /* 3/0 */
 128                         p_ac3dec->downmix.downmix_3f_0r_to_2ch (p_ac3dec->samples[0], &p_ac3dec->dm_par);
 129                         break;
 130                 case 2:
 131                         break;
 132                 default:        /* 1/0 */
 133 //                      if (p_ac3dec->bsi.acmod == 1)
 134                                 center = p_ac3dec->samples[0];
 135 //                      else if (p_ac3dec->bsi.acmod == 0)
 136 //                  center = samples[ac3_config.dual_mono_ch_sel];
 137                 do_imdct(&p_ac3dec->imdct, center, p_ac3dec->imdct.delay[0]); /* no downmix*/
 138
 139                         p_ac3dec->downmix.stream_sample_1ch_to_s16 (buffer, center);
 140
 141                     return;
 142                 break;
 143         }
 144
 145                 do_imdct (&p_ac3dec->imdct, p_ac3dec->samples[0], p_ac3dec->imdct.delay[0]);
 146                 do_imdct (&p_ac3dec->imdct, p_ac3dec->samples[1], p_ac3dec->imdct.delay[1]);
 147                 p_ac3dec->downmix.stream_sample_2ch_to_s16(buffer, p_ac3dec->samples[0], p_ac3dec->samples[1]);
 148
 149         } else {
 150         /* imdct and then downmix
 151                  * delay and samples should be saved and mixed
 152                  * fprintf(stderr, "time domain downmix\n"); */
 153                 for (i=0; i<p_ac3dec->bsi.nfchans; i++)
 154         {
 155                         if (p_ac3dec->audblk.blksw[i])
 156                 /* There is only a C function */
 157                                 imdct_do_256_nol (&p_ac3dec->imdct, p_ac3dec->samples[i], p_ac3dec->imdct.delay1[i]);
 158                         else
 159                                 p_ac3dec->imdct.imdct_do_512_nol (&p_ac3dec->imdct, p_ac3dec->samples[i], p_ac3dec->imdct.delay1[i]);
 160                 }
 161
 162                 /* mix the sample, overlap */
 163                 switch(p_ac3dec->bsi.acmod)
 164         {
 165                 case 7:         /* 3/2 */
 166                         left = p_ac3dec->samples[0];
 167                         center = p_ac3dec->samples[1];
 168                         right = p_ac3dec->samples[2];
 169                         left_sur = p_ac3dec->samples[3];
 170                         right_sur = p_ac3dec->samples[4];
 171                         delay_left = p_ac3dec->imdct.delay[0];
 172                         delay_right = p_ac3dec->imdct.delay[1];
 173                         delay1_left = p_ac3dec->imdct.delay1[0];
 174                         delay1_center = p_ac3dec->imdct.delay1[1];
 175                         delay1_right = p_ac3dec->imdct.delay1[2];
 176                 delay1_sl = p_ac3dec->imdct.delay1[3];
 177                         delay1_sr = p_ac3dec->imdct.delay1[4];
 178
 179                         for (i = 0; i < 256; i++) {
 180                                 left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  + p_ac3dec->dm_par.slev * *left_sur++;
 181                                 right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 182                                 *buffer++ = (s16)(left_tmp + *delay_left);
 183                                 *buffer++ = (s16)(right_tmp + *delay_right);
 184                                 *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl++;
 185                                 *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 186                         }
 187                         break;
 188                 case 6:         /* 2/2 */
 189                         left = p_ac3dec->samples[0];
 190                         right = p_ac3dec->samples[1];
 191                         left_sur = p_ac3dec->samples[2];
 192                         right_sur = p_ac3dec->samples[3];
 193                         delay_left = p_ac3dec->imdct.delay[0];
 194                         delay_right = p_ac3dec->imdct.delay[1];
 195                         delay1_left = p_ac3dec->imdct.delay1[0];
 196                         delay1_right = p_ac3dec->imdct.delay1[1];
 197                         delay1_sl = p_ac3dec->imdct.delay1[2];
 198                         delay1_sr = p_ac3dec->imdct.delay1[3];
 199
 200                         for (i = 0; i < 256; i++) {
 201                                 left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.slev * *left_sur++;
 202                                 right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 203                                 *buffer++ = (s16)(left_tmp + *delay_left);
 204                                 *buffer++ = (s16)(right_tmp + *delay_right);
 205                                 *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.slev * *delay1_sl++;
 206                                 *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 207                         }
 208                         break;
 209                 case 5:         /* 3/1 */
 210                         left = p_ac3dec->samples[0];
 211                         center = p_ac3dec->samples[1];
 212                         right = p_ac3dec->samples[2];
 213                         right_sur = p_ac3dec->samples[3];
 214                         delay_left = p_ac3dec->imdct.delay[0];
 215                         delay_right = p_ac3dec->imdct.delay[1];
 216                         delay1_left = p_ac3dec->imdct.delay1[0];
 217                         delay1_center = p_ac3dec->imdct.delay1[1];
 218                         delay1_right = p_ac3dec->imdct.delay1[2];
 219                         delay1_sl = p_ac3dec->imdct.delay1[3];
 220
 221                         for (i = 0; i < 256; i++) {
 222                                 left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  - p_ac3dec->dm_par.slev * *right_sur;
 223                                 right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 224                                 *buffer++ = (s16)(left_tmp + *delay_left);
 225                                 *buffer++ = (s16)(right_tmp + *delay_right);
 226                                 *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl;
 227                                 *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 228                         }
 229                         break;
 230                 case 4:         /* 2/1 */
 231                         left = p_ac3dec->samples[0];
 232                         right = p_ac3dec->samples[1];
 233                         right_sur = p_ac3dec->samples[2];
 234                         delay_left = p_ac3dec->imdct.delay[0];
 235                         delay_right = p_ac3dec->imdct.delay[1];
 236                         delay1_left = p_ac3dec->imdct.delay1[0];
 237                         delay1_right = p_ac3dec->imdct.delay1[1];
 238                         delay1_sl = p_ac3dec->imdct.delay1[2];
 239
 240                         for (i = 0; i < 256; i++) {
 241                                 left_tmp = p_ac3dec->dm_par.unit * *left++ - p_ac3dec->dm_par.slev * *right_sur;
 242                                 right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 243                                 *buffer++ = (s16)(left_tmp + *delay_left);
 244                                 *buffer++ = (s16)(right_tmp + *delay_right);
 245                                 *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++ + p_ac3dec->dm_par.slev * *delay1_sl;
 246                                 *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 247                         }
 248                         break;
 249                 case 3:         /* 3/0 */
 250                         left = p_ac3dec->samples[0];
 251                         center = p_ac3dec->samples[1];
 252                         right = p_ac3dec->samples[2];
 253                         delay_left = p_ac3dec->imdct.delay[0];
 254                         delay_right = p_ac3dec->imdct.delay[1];
 255                         delay1_left = p_ac3dec->imdct.delay1[0];
 256                         delay1_center = p_ac3dec->imdct.delay1[1];
 257                         delay1_right = p_ac3dec->imdct.delay1[2];
 258
 259                         for (i = 0; i < 256; i++) {
 260                                 left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center;
 261                                 right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++;
 262                                 *buffer++ = (s16)(left_tmp + *delay_left);
 263                                 *buffer++ = (s16)(right_tmp + *delay_right);
 264                                 *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center;
 265                                 *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++;
 266                         }
 267                         break;
 268                 case 2:         /* copy to output */
 269                         for (i = 0; i < 256; i++) {
 270                                 *buffer++ = (s16)p_ac3dec->samples[0][i];
 271                                 *buffer++ = (s16)p_ac3dec->samples[1][i];
 272                         }
 273                         break;
 274                 }
 275         }
 276 }