liba52/resample_c.c

   1 /*
   2  * resample_c.c
   3  * Copyright (C) 2001 Árpád Gereöffy
   4  *
   5  * This file is part of a52dec, a free ATSC A-52 stream decoder.
   6  * See http://liba52.sourceforge.net/ for updates.
   7  *
   8  * File added for use with MPlayer and not part of original a52dec.
   9  *
  10  * a52dec is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * a52dec is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23  */
  24
  25 static inline int16_t convert (int32_t i)
  26 {
  27     if (i > 0x43c07fff)
  28         return 32767;
  29     else if (i < 0x43bf8000)
  30         return -32768;
  31     else
  32         return i - 0x43c00000;
  33 }
  34
  35 static int a52_resample_MONO_to_5_C(float * _f, int16_t * s16){
  36     int i;
  37     int32_t * f = (int32_t *) _f;
  38         for (i = 0; i < 256; i++) {
  39             s16[5*i] = s16[5*i+1] = s16[5*i+2] = s16[5*i+3] = 0;
  40             s16[5*i+4] = convert (f[i]);
  41         }
  42     return 5*256;
  43 }
  44
  45 static int a52_resample_MONO_to_1_C(float * _f, int16_t * s16){
  46     int i;
  47     int32_t * f = (int32_t *) _f;
  48         for (i = 0; i < 256; i++) {
  49             s16[i] = convert (f[i]);
  50         }
  51     return 1*256;
  52 }
  53
  54 static int a52_resample_STEREO_to_2_C(float * _f, int16_t * s16){
  55     int i;
  56     int32_t * f = (int32_t *) _f;
  57         for (i = 0; i < 256; i++) {
  58             s16[2*i] = convert (f[i]);
  59             s16[2*i+1] = convert (f[i+256]);
  60         }
  61     return 2*256;
  62 }
  63
  64 static int a52_resample_3F_to_5_C(float * _f, int16_t * s16){
  65     int i;
  66     int32_t * f = (int32_t *) _f;
  67         for (i = 0; i < 256; i++) {
  68             s16[5*i] = convert (f[i]);
  69             s16[5*i+1] = convert (f[i+512]);
  70             s16[5*i+2] = s16[5*i+3] = 0;
  71             s16[5*i+4] = convert (f[i+256]);
  72         }
  73     return 5*256;
  74 }
  75
  76 static int a52_resample_2F_2R_to_4_C(float * _f, int16_t * s16){
  77     int i;
  78     int32_t * f = (int32_t *) _f;
  79         for (i = 0; i < 256; i++) {
  80             s16[4*i] = convert (f[i]);
  81             s16[4*i+1] = convert (f[i+256]);
  82             s16[4*i+2] = convert (f[i+512]);
  83             s16[4*i+3] = convert (f[i+768]);
  84         }
  85     return 4*256;
  86 }
  87
  88 static int a52_resample_3F_2R_to_5_C(float * _f, int16_t * s16){
  89     int i;
  90     int32_t * f = (int32_t *) _f;
  91         for (i = 0; i < 256; i++) {
  92             s16[5*i] = convert (f[i]);
  93             s16[5*i+1] = convert (f[i+512]);
  94             s16[5*i+2] = convert (f[i+768]);
  95             s16[5*i+3] = convert (f[i+1024]);
  96             s16[5*i+4] = convert (f[i+256]);
  97         }
  98     return 5*256;
  99 }
 100
 101 static int a52_resample_MONO_LFE_to_6_C(float * _f, int16_t * s16){
 102     int i;
 103     int32_t * f = (int32_t *) _f;
 104         for (i = 0; i < 256; i++) {
 105             s16[6*i] = s16[6*i+1] = s16[6*i+2] = s16[6*i+3] = 0;
 106             s16[6*i+4] = convert (f[i+256]);
 107             s16[6*i+5] = convert (f[i]);
 108         }
 109     return 6*256;
 110 }
 111
 112 static int a52_resample_STEREO_LFE_to_6_C(float * _f, int16_t * s16){
 113     int i;
 114     int32_t * f = (int32_t *) _f;
 115         for (i = 0; i < 256; i++) {
 116             s16[6*i] = convert (f[i+256]);
 117             s16[6*i+1] = convert (f[i+512]);
 118             s16[6*i+2] = s16[6*i+3] = s16[6*i+4] = 0;
 119             s16[6*i+5] = convert (f[i]);
 120         }
 121     return 6*256;
 122 }
 123
 124 static int a52_resample_3F_LFE_to_6_C(float * _f, int16_t * s16){
 125     int i;
 126     int32_t * f = (int32_t *) _f;
 127         for (i = 0; i < 256; i++) {
 128             s16[6*i] = convert (f[i+256]);
 129             s16[6*i+1] = convert (f[i+768]);
 130             s16[6*i+2] = s16[6*i+3] = 0;
 131             s16[6*i+4] = convert (f[i+512]);
 132             s16[6*i+5] = convert (f[i]);
 133         }
 134     return 6*256;
 135 }
 136
 137 static int a52_resample_2F_2R_LFE_to_6_C(float * _f, int16_t * s16){
 138     int i;
 139     int32_t * f = (int32_t *) _f;
 140         for (i = 0; i < 256; i++) {
 141             s16[6*i] = convert (f[i+256]);
 142             s16[6*i+1] = convert (f[i+512]);
 143             s16[6*i+2] = convert (f[i+768]);
 144             s16[6*i+3] = convert (f[i+1024]);
 145             s16[6*i+4] = 0;
 146             s16[6*i+5] = convert (f[i]);
 147         }
 148     return 6*256;
 149 }
 150
 151 static int a52_resample_3F_2R_LFE_to_6_C(float * _f, int16_t * s16){
 152     int i;
 153     int32_t * f = (int32_t *) _f;
 154         for (i = 0; i < 256; i++) {
 155             s16[6*i] = convert (f[i+256]);
 156             s16[6*i+1] = convert (f[i+768]);
 157             s16[6*i+2] = convert (f[i+1024]);
 158             s16[6*i+3] = convert (f[i+1280]);
 159             s16[6*i+4] = convert (f[i+512]);
 160             s16[6*i+5] = convert (f[i]);
 161         }
 162     return 6*256;
 163 }
 164
 165
 166 static void* a52_resample_C(int flags, int ch){
 167     switch (flags) {
 168     case A52_MONO:
 169         if(ch==5) return a52_resample_MONO_to_5_C;
 170         if(ch==1) return a52_resample_MONO_to_1_C;
 171         break;
 172     case A52_CHANNEL:
 173     case A52_STEREO:
 174     case A52_DOLBY:
 175         if(ch==2) return a52_resample_STEREO_to_2_C;
 176         break;
 177     case A52_3F:
 178         if(ch==5) return a52_resample_3F_to_5_C;
 179         break;
 180     case A52_2F2R:
 181         if(ch==4) return a52_resample_2F_2R_to_4_C;
 182         break;
 183     case A52_3F2R:
 184         if(ch==5) return a52_resample_3F_2R_to_5_C;
 185         break;
 186     case A52_MONO | A52_LFE:
 187         if(ch==6) return a52_resample_MONO_LFE_to_6_C;
 188         break;
 189     case A52_CHANNEL | A52_LFE:
 190     case A52_STEREO | A52_LFE:
 191     case A52_DOLBY | A52_LFE:
 192         if(ch==6) return a52_resample_STEREO_LFE_to_6_C;
 193         break;
 194     case A52_3F | A52_LFE:
 195         if(ch==6) return a52_resample_3F_LFE_to_6_C;
 196         break;
 197     case A52_2F2R | A52_LFE:
 198         if(ch==6) return a52_resample_2F_2R_LFE_to_6_C;
 199         break;
 200     case A52_3F2R | A52_LFE:
 201         if(ch==6) return a52_resample_3F_2R_LFE_to_6_C;
 202         break;
 203     }
 204     return NULL;
 205 }