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 1.20 2001/05/15 16:19:42 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 "config.h"
  37 #include "common.h"
  38 #include "threads.h"
  39 #include "mtime.h"
  40
  41 #include "stream_control.h"
  42 #include "input_ext-dec.h"
  43
  44 #include "ac3_imdct.h"
  45 #include "ac3_downmix.h"
  46 #include "ac3_decoder.h"
  47
  48 #ifndef M_PI
  49 #   define M_PI 3.14159265358979323846
  50 #endif
  51
  52 void imdct_init(imdct_t * p_imdct)
  53 {
  54     int i;
  55     float scale = 181.019;
  56
  57         p_imdct->pf_imdct_init( p_imdct );
  58
  59     /* More twiddle factors to turn IFFT into IMDCT */
  60     for (i=0; i < 64; i++) {
  61         p_imdct->xcos2[i] = cos(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  62         p_imdct->xsin2[i] = sin(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  63     }
  64 }
  65
  66 void imdct (ac3dec_t * p_ac3dec, s16 * buffer)
  67 {
  68     int   i;
  69     int   doable = 0;
  70     float *center=NULL, *left, *right, *left_sur, *right_sur;
  71     float *delay_left, *delay_right;
  72     float *delay1_left, *delay1_right, *delay1_center, *delay1_sr, *delay1_sl;
  73     float right_tmp, left_tmp;
  74     void (*do_imdct)(imdct_t * p_imdct, float data[], float delay[]);
  75
  76     /* test if dm in frequency is doable */
  77     if (!(doable = p_ac3dec->audblk.blksw[0]))
  78     {
  79         do_imdct = p_ac3dec->imdct.pf_imdct_512;
  80     }
  81     else
  82     {
  83         do_imdct = p_ac3dec->imdct.pf_imdct_256;
  84     }
  85
  86     /* downmix in the frequency domain if all the channels
  87      * use the same imdct */
  88     for (i=0; i < p_ac3dec->bsi.nfchans; i++)
  89     {
  90         if (doable != p_ac3dec->audblk.blksw[i])
  91         {
  92             do_imdct = NULL;
  93             break;
  94         }
  95     }
  96
  97     if (do_imdct)
  98     {
  99         /* dowmix first and imdct */
 100         switch(p_ac3dec->bsi.acmod)
 101         {
 102             case 7:        /* 3/2 */
 103                 p_ac3dec->downmix.pf_downmix_3f_2r_to_2ch (p_ac3dec->samples[0], &p_ac3dec->dm_par);
 104                 break;
 105             case 6:        /* 2/2 */
 106                 p_ac3dec->downmix.pf_downmix_2f_2r_to_2ch (p_ac3dec->samples[0], &p_ac3dec->dm_par);
 107                 break;
 108             case 5:        /* 3/1 */
 109                 p_ac3dec->downmix.pf_downmix_3f_1r_to_2ch (p_ac3dec->samples[0], &p_ac3dec->dm_par);
 110                 break;
 111             case 4:        /* 2/1 */
 112                 p_ac3dec->downmix.pf_downmix_2f_1r_to_2ch (p_ac3dec->samples[0], &p_ac3dec->dm_par);
 113                 break;
 114             case 3:        /* 3/0 */
 115                 p_ac3dec->downmix.pf_downmix_3f_0r_to_2ch (p_ac3dec->samples[0], &p_ac3dec->dm_par);
 116                 break;
 117             case 2:
 118                 break;
 119             default:    /* 1/0 */
 120 //                if (p_ac3dec->bsi.acmod == 1)
 121                     center = p_ac3dec->samples[0];
 122 //                else if (p_ac3dec->bsi.acmod == 0)
 123 //                  center = samples[ac3_config.dual_mono_ch_sel];
 124                 do_imdct(&p_ac3dec->imdct, center, p_ac3dec->imdct.delay[0]); /* no downmix*/
 125
 126                 p_ac3dec->downmix.pf_stream_sample_1ch_to_s16 (buffer, center);
 127
 128                 return;
 129                 break;
 130         }
 131
 132         do_imdct (&p_ac3dec->imdct, p_ac3dec->samples[0], p_ac3dec->imdct.delay[0]);
 133         do_imdct (&p_ac3dec->imdct, p_ac3dec->samples[1], p_ac3dec->imdct.delay[1]);
 134         p_ac3dec->downmix.pf_stream_sample_2ch_to_s16(buffer, p_ac3dec->samples[0], p_ac3dec->samples[1]);
 135
 136     } else {
 137         /* imdct and then downmix
 138          * delay and samples should be saved and mixed
 139          * fprintf(stderr, "time domain downmix\n"); */
 140         for (i=0; i<p_ac3dec->bsi.nfchans; i++)
 141         {
 142             if (p_ac3dec->audblk.blksw[i])
 143                 /* There is only a C function */
 144                 p_ac3dec->imdct.pf_imdct_256_nol (&p_ac3dec->imdct, p_ac3dec->samples[i], p_ac3dec->imdct.delay1[i]);
 145             else
 146                 p_ac3dec->imdct.pf_imdct_512_nol (&p_ac3dec->imdct, p_ac3dec->samples[i], p_ac3dec->imdct.delay1[i]);
 147         }
 148
 149         /* mix the sample, overlap */
 150         switch(p_ac3dec->bsi.acmod)
 151         {
 152             case 7:        /* 3/2 */
 153                 left = p_ac3dec->samples[0];
 154                 center = p_ac3dec->samples[1];
 155                 right = p_ac3dec->samples[2];
 156                 left_sur = p_ac3dec->samples[3];
 157                 right_sur = p_ac3dec->samples[4];
 158                 delay_left = p_ac3dec->imdct.delay[0];
 159                 delay_right = p_ac3dec->imdct.delay[1];
 160                 delay1_left = p_ac3dec->imdct.delay1[0];
 161                 delay1_center = p_ac3dec->imdct.delay1[1];
 162                 delay1_right = p_ac3dec->imdct.delay1[2];
 163                 delay1_sl = p_ac3dec->imdct.delay1[3];
 164                 delay1_sr = p_ac3dec->imdct.delay1[4];
 165
 166                 for (i = 0; i < 256; i++) {
 167                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  + p_ac3dec->dm_par.slev * *left_sur++;
 168                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 169                     *buffer++ = (s16)(left_tmp + *delay_left);
 170                     *buffer++ = (s16)(right_tmp + *delay_right);
 171                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl++;
 172                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 173                 }
 174                 break;
 175             case 6:        /* 2/2 */
 176                 left = p_ac3dec->samples[0];
 177                 right = p_ac3dec->samples[1];
 178                 left_sur = p_ac3dec->samples[2];
 179                 right_sur = p_ac3dec->samples[3];
 180                 delay_left = p_ac3dec->imdct.delay[0];
 181                 delay_right = p_ac3dec->imdct.delay[1];
 182                 delay1_left = p_ac3dec->imdct.delay1[0];
 183                 delay1_right = p_ac3dec->imdct.delay1[1];
 184                 delay1_sl = p_ac3dec->imdct.delay1[2];
 185                 delay1_sr = p_ac3dec->imdct.delay1[3];
 186
 187                 for (i = 0; i < 256; i++) {
 188                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.slev * *left_sur++;
 189                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 190                     *buffer++ = (s16)(left_tmp + *delay_left);
 191                     *buffer++ = (s16)(right_tmp + *delay_right);
 192                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.slev * *delay1_sl++;
 193                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 194                 }
 195                 break;
 196             case 5:        /* 3/1 */
 197                 left = p_ac3dec->samples[0];
 198                 center = p_ac3dec->samples[1];
 199                 right = p_ac3dec->samples[2];
 200                 right_sur = p_ac3dec->samples[3];
 201                 delay_left = p_ac3dec->imdct.delay[0];
 202                 delay_right = p_ac3dec->imdct.delay[1];
 203                 delay1_left = p_ac3dec->imdct.delay1[0];
 204                 delay1_center = p_ac3dec->imdct.delay1[1];
 205                 delay1_right = p_ac3dec->imdct.delay1[2];
 206                 delay1_sl = p_ac3dec->imdct.delay1[3];
 207
 208                 for (i = 0; i < 256; i++) {
 209                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  - p_ac3dec->dm_par.slev * *right_sur;
 210                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 211                     *buffer++ = (s16)(left_tmp + *delay_left);
 212                     *buffer++ = (s16)(right_tmp + *delay_right);
 213                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl;
 214                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 215                 }
 216                 break;
 217             case 4:        /* 2/1 */
 218                 left = p_ac3dec->samples[0];
 219                 right = p_ac3dec->samples[1];
 220                 right_sur = p_ac3dec->samples[2];
 221                 delay_left = p_ac3dec->imdct.delay[0];
 222                 delay_right = p_ac3dec->imdct.delay[1];
 223                 delay1_left = p_ac3dec->imdct.delay1[0];
 224                 delay1_right = p_ac3dec->imdct.delay1[1];
 225                 delay1_sl = p_ac3dec->imdct.delay1[2];
 226
 227                 for (i = 0; i < 256; i++) {
 228                     left_tmp = p_ac3dec->dm_par.unit * *left++ - p_ac3dec->dm_par.slev * *right_sur;
 229                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 230                     *buffer++ = (s16)(left_tmp + *delay_left);
 231                     *buffer++ = (s16)(right_tmp + *delay_right);
 232                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++ + p_ac3dec->dm_par.slev * *delay1_sl;
 233                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 234                 }
 235                 break;
 236             case 3:        /* 3/0 */
 237                 left = p_ac3dec->samples[0];
 238                 center = p_ac3dec->samples[1];
 239                 right = p_ac3dec->samples[2];
 240                 delay_left = p_ac3dec->imdct.delay[0];
 241                 delay_right = p_ac3dec->imdct.delay[1];
 242                 delay1_left = p_ac3dec->imdct.delay1[0];
 243                    delay1_center = p_ac3dec->imdct.delay1[1];
 244                 delay1_right = p_ac3dec->imdct.delay1[2];
 245
 246                 for (i = 0; i < 256; i++) {
 247                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center;
 248                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++;
 249                     *buffer++ = (s16)(left_tmp + *delay_left);
 250                     *buffer++ = (s16)(right_tmp + *delay_right);
 251                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center;
 252                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++;
 253                 }
 254                 break;
 255             case 2:        /* copy to output */
 256                 for (i = 0; i < 256; i++) {
 257                     *buffer++ = (s16)p_ac3dec->samples[0][i];
 258                     *buffer++ = (s16)p_ac3dec->samples[1][i];
 259                 }
 260                 break;
 261         }
 262     }
 263 }