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 1.7 2001/12/30 07:09:54 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 <videolan/vlc.h>
  35
  36 #include "stream_control.h"
  37 #include "input_ext-dec.h"
  38
  39 #include "ac3_imdct.h"
  40 #include "ac3_downmix.h"
  41 #include "ac3_decoder.h"
  42
  43 #ifndef M_PI
  44 #   define M_PI 3.14159265358979323846
  45 #endif
  46
  47 void imdct_init(imdct_t * p_imdct)
  48 {
  49     int i;
  50     float scale = 181.019;
  51
  52     p_imdct->pf_imdct_init( p_imdct );
  53
  54     /* More twiddle factors to turn IFFT into IMDCT */
  55     for (i=0; i < 64; i++) {
  56         p_imdct->xcos2[i] = cos(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  57         p_imdct->xsin2[i] = sin(2.0f * M_PI * (8*i+1)/(4*N)) * scale;
  58     }
  59 }
  60
  61 void imdct (ac3dec_t * p_ac3dec, s16 * buffer)
  62 {
  63     int   i;
  64     int   doable = 0;
  65     float *center=NULL, *left, *right, *left_sur, *right_sur;
  66     float *delay_left, *delay_right;
  67     float *delay1_left, *delay1_right, *delay1_center, *delay1_sr, *delay1_sl;
  68     float right_tmp, left_tmp;
  69     void (*do_imdct)(imdct_t * p_imdct, float data[], float delay[]);
  70
  71     /* test if dm in frequency is doable */
  72     if (!(doable = p_ac3dec->audblk.blksw[0]))
  73     {
  74         do_imdct = p_ac3dec->imdct->pf_imdct_512;
  75     }
  76     else
  77     {
  78         do_imdct = p_ac3dec->imdct->pf_imdct_256;
  79     }
  80
  81     /* downmix in the frequency domain if all the channels
  82      * use the same imdct */
  83     for (i=0; i < p_ac3dec->bsi.nfchans; i++)
  84     {
  85         if (doable != p_ac3dec->audblk.blksw[i])
  86         {
  87             do_imdct = NULL;
  88             break;
  89         }
  90     }
  91
  92     if (do_imdct)
  93     {
  94         /* dowmix first and imdct */
  95         switch(p_ac3dec->bsi.acmod)
  96         {
  97             case 7:        /* 3/2 */
  98                 p_ac3dec->downmix.pf_downmix_3f_2r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
  99                 break;
 100             case 6:        /* 2/2 */
 101                 p_ac3dec->downmix.pf_downmix_2f_2r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 102                 break;
 103             case 5:        /* 3/1 */
 104                 p_ac3dec->downmix.pf_downmix_3f_1r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 105                 break;
 106             case 4:        /* 2/1 */
 107                 p_ac3dec->downmix.pf_downmix_2f_1r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 108                 break;
 109             case 3:        /* 3/0 */
 110                 p_ac3dec->downmix.pf_downmix_3f_0r_to_2ch (p_ac3dec->samples, &p_ac3dec->dm_par);
 111                 break;
 112             case 2:
 113                 break;
 114             default:    /* 1/0 */
 115 //                if (p_ac3dec->bsi.acmod == 1)
 116                     center = p_ac3dec->samples;
 117 //                else if (p_ac3dec->bsi.acmod == 0)
 118 //                  center = samples[ac3_config.dual_mono_ch_sel];
 119                 do_imdct(p_ac3dec->imdct, center, p_ac3dec->imdct->delay); /* no downmix*/
 120
 121                 p_ac3dec->downmix.pf_stream_sample_1ch_to_s16 (buffer, center);
 122
 123                 return;
 124                 break;
 125         }
 126
 127         do_imdct (p_ac3dec->imdct, p_ac3dec->samples, p_ac3dec->imdct->delay);
 128         do_imdct (p_ac3dec->imdct, p_ac3dec->samples+256, p_ac3dec->imdct->delay+256);
 129         p_ac3dec->downmix.pf_stream_sample_2ch_to_s16(buffer, p_ac3dec->samples, p_ac3dec->samples+256);
 130
 131     } else {
 132         /* imdct and then downmix
 133          * delay and samples should be saved and mixed
 134          * fprintf(stderr, "time domain downmix\n"); */
 135         for (i=0; i<p_ac3dec->bsi.nfchans; i++)
 136         {
 137             if (p_ac3dec->audblk.blksw[i])
 138             {
 139                 /* There is only a C function */
 140                 p_ac3dec->imdct->pf_imdct_256_nol( p_ac3dec->imdct,
 141                      p_ac3dec->samples+256*i, p_ac3dec->imdct->delay1+256*i );
 142             }
 143             else
 144             {
 145                 p_ac3dec->imdct->pf_imdct_512_nol( p_ac3dec->imdct,
 146                      p_ac3dec->samples+256*i, p_ac3dec->imdct->delay1+256*i );
 147             }
 148         }
 149
 150         /* mix the sample, overlap */
 151         switch(p_ac3dec->bsi.acmod)
 152         {
 153             case 7:        /* 3/2 */
 154                 left = p_ac3dec->samples;
 155                 center = p_ac3dec->samples+256;
 156                 right = p_ac3dec->samples+2*256;
 157                 left_sur = p_ac3dec->samples+3*256;
 158                 right_sur = p_ac3dec->samples+4*256;
 159                 delay_left = p_ac3dec->imdct->delay;
 160                 delay_right = p_ac3dec->imdct->delay+256;
 161                 delay1_left = p_ac3dec->imdct->delay1;
 162                 delay1_center = p_ac3dec->imdct->delay1+256;
 163                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 164                 delay1_sl = p_ac3dec->imdct->delay1+3*256;
 165                 delay1_sr = p_ac3dec->imdct->delay1+4*256;
 166
 167                 for (i = 0; i < 256; i++) {
 168                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  + p_ac3dec->dm_par.slev * *left_sur++;
 169                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 170                     *buffer++ = (s16)(left_tmp + *delay_left);
 171                     *buffer++ = (s16)(right_tmp + *delay_right);
 172                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl++;
 173                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 174                 }
 175                 break;
 176             case 6:        /* 2/2 */
 177                 left = p_ac3dec->samples;
 178                 right = p_ac3dec->samples+256;
 179                 left_sur = p_ac3dec->samples+2*256;
 180                 right_sur = p_ac3dec->samples+3*256;
 181                 delay_left = p_ac3dec->imdct->delay;
 182                 delay_right = p_ac3dec->imdct->delay+256;
 183                 delay1_left = p_ac3dec->imdct->delay1;
 184                 delay1_right = p_ac3dec->imdct->delay1+256;
 185                 delay1_sl = p_ac3dec->imdct->delay1+2*256;
 186                 delay1_sr = p_ac3dec->imdct->delay1+3*256;
 187
 188                 for (i = 0; i < 256; i++) {
 189                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.slev * *left_sur++;
 190                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 191                     *buffer++ = (s16)(left_tmp + *delay_left);
 192                     *buffer++ = (s16)(right_tmp + *delay_right);
 193                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.slev * *delay1_sl++;
 194                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sr++;
 195                 }
 196                 break;
 197             case 5:        /* 3/1 */
 198                 left = p_ac3dec->samples;
 199                 center = p_ac3dec->samples+256;
 200                 right = p_ac3dec->samples+2*256;
 201                 right_sur = p_ac3dec->samples+3*256;
 202                 delay_left = p_ac3dec->imdct->delay;
 203                 delay_right = p_ac3dec->imdct->delay+256;
 204                 delay1_left = p_ac3dec->imdct->delay1;
 205                 delay1_center = p_ac3dec->imdct->delay1+256;
 206                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 207                 delay1_sl = p_ac3dec->imdct->delay1+3*256;
 208
 209                 for (i = 0; i < 256; i++) {
 210                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center  - p_ac3dec->dm_par.slev * *right_sur;
 211                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *right_sur++;
 212                     *buffer++ = (s16)(left_tmp + *delay_left);
 213                     *buffer++ = (s16)(right_tmp + *delay_right);
 214                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center  + p_ac3dec->dm_par.slev * *delay1_sl;
 215                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 216                 }
 217                 break;
 218             case 4:        /* 2/1 */
 219                 left = p_ac3dec->samples;
 220                 right = p_ac3dec->samples+256;
 221                 right_sur = p_ac3dec->samples+2*256;
 222                 delay_left = p_ac3dec->imdct->delay;
 223                 delay_right = p_ac3dec->imdct->delay+256;
 224                 delay1_left = p_ac3dec->imdct->delay1;
 225                 delay1_right = p_ac3dec->imdct->delay1+256;
 226                 delay1_sl = p_ac3dec->imdct->delay1+2*256;
 227
 228                 for (i = 0; i < 256; i++) {
 229                     left_tmp = p_ac3dec->dm_par.unit * *left++ - p_ac3dec->dm_par.slev * *right_sur;
 230                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.slev * *right_sur++;
 231                     *buffer++ = (s16)(left_tmp + *delay_left);
 232                     *buffer++ = (s16)(right_tmp + *delay_right);
 233                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++ + p_ac3dec->dm_par.slev * *delay1_sl;
 234                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.slev * *delay1_sl++;
 235                 }
 236                 break;
 237             case 3:        /* 3/0 */
 238                 left = p_ac3dec->samples;
 239                 center = p_ac3dec->samples+256;
 240                 right = p_ac3dec->samples+2*256;
 241                 delay_left = p_ac3dec->imdct->delay;
 242                 delay_right = p_ac3dec->imdct->delay+256;
 243                 delay1_left = p_ac3dec->imdct->delay1;
 244                 delay1_center = p_ac3dec->imdct->delay1+256;
 245                 delay1_right = p_ac3dec->imdct->delay1+2*256;
 246
 247                 for (i = 0; i < 256; i++) {
 248                     left_tmp = p_ac3dec->dm_par.unit * *left++  + p_ac3dec->dm_par.clev * *center;
 249                     right_tmp= p_ac3dec->dm_par.unit * *right++ + p_ac3dec->dm_par.clev * *center++;
 250                     *buffer++ = (s16)(left_tmp + *delay_left);
 251                     *buffer++ = (s16)(right_tmp + *delay_right);
 252                     *delay_left++ = p_ac3dec->dm_par.unit * *delay1_left++  + p_ac3dec->dm_par.clev * *delay1_center;
 253                     *delay_right++ = p_ac3dec->dm_par.unit * *delay1_right++ + p_ac3dec->dm_par.clev * *center++;
 254                 }
 255                 break;
 256             case 2:        /* copy to output */
 257                 for (i = 0; i < 256; i++) {
 258                     *buffer++ = (s16) *(p_ac3dec->samples+i);
 259                     *buffer++ = (s16) *(p_ac3dec->samples+256+i);
 260                 }
 261                 break;
 262         }
 263     }
 264 }