input.c

   1 /*
   2
   3     PROGRAM_NAME PROGRAM_VERSION - PROGRAM_DESCRIPTION
   4
   5     Copyright (C) 2003 Angel Ortega <angel@triptico.com>
   6
   7     This program is free software; you can redistribute it and/or
   8     modify it under the terms of the GNU General Public License
   9     as published by the Free Software Foundation; either version 2
  10     of the License, or (at your option) any later version.
  11
  12     This program is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with this program; if not, write to the Free Software
  19     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  20
  21     http://www.triptico.com
  22
  23 */
  24
  25 #include "config.h"
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29
  30 #include "input.h"
  31
  32 /*******************
  33         Data
  34 ********************/
  35
  36 extern int _frequency;
  37
  38
  39 /*******************
  40         Code
  41 ********************/
  42
  43 int fget16(FILE * f)
  44 {
  45         int c;
  46
  47         c=fgetc(f);
  48         c+=(fgetc(f) * 256);
  49
  50         return(c);
  51 }
  52
  53
  54 int fget32(FILE * f)
  55 {
  56         int c;
  57
  58         c=fgetc(f);
  59         c+=(fgetc(f) * 256);
  60         c+=(fgetc(f) * 65536);
  61         c+=(fgetc(f) * 16777216);
  62
  63         return(c);
  64 }
  65
  66
  67 int load_sample(FILE * f, int bits)
  68 {
  69         short int s;
  70
  71         if(bits==8)
  72         {
  73                 s=fgetc(f)-128;
  74                 s<<=8;
  75         }
  76         else
  77         {
  78 /*              s=fgetc(f);
  79                 s|=(((unsigned char)fgetc(f)) << 8);*/
  80                 s=fget16(f);
  81         }
  82
  83         return(s);
  84 }
  85
  86
  87 void load_pcm_wave(FILE * f, int * size, int bits, int channels,
  88         int frequency, int ** lwave, int ** rwave)
  89 {
  90         int n;
  91         int * ls;
  92         int * rs;
  93
  94         ls=(int *)malloc(*size * sizeof(int));
  95
  96         if(channels==2)
  97                 rs=(int *)malloc(*size * sizeof(int));
  98         else
  99                 rs=ls;
 100
 101         for(n=0;n < *size;n++)
 102         {
 103                 ls[n]=load_sample(f, bits);
 104
 105                 if(channels==2)
 106                         rs[n]=load_sample(f, bits);
 107         }
 108
 109         /* resample if needed */
 110         if(frequency != _frequency)
 111         {
 112                 ls=wave_resample(ls, frequency, size);
 113
 114                 if(channels==2)
 115                         rs=wave_resample(rs, frequency, size);
 116                 else
 117                         rs=ls;
 118         }
 119
 120         *lwave=ls;
 121         *rwave=rs;
 122 }
 123
 124
 125 int * wave_resample(int * wave, int freq, int * size)
 126 {
 127         double ratio;
 128         int new_size;
 129         int * new_wave;
 130         int n;
 131         double i;
 132
 133         ratio=(double) freq / (double) _frequency;
 134         new_size=(int)((double) (*size) / ratio);
 135
 136         new_wave=(int *)malloc(new_size * sizeof(int));
 137
 138         printf("wave_resample: ratio %f\n", (float)ratio);
 139
 140         for(n=i=0;n < new_size;n++,i+=ratio)
 141                 new_wave[n]=wave[(int)i];
 142
 143         *size=new_size;
 144
 145         /* free the old wave */
 146         free(wave);
 147
 148         return(new_wave);
 149 }
 150
 151
 152 int load_wav_file(char * filename, int * size, int ** lwave, int ** rwave)
 153 {
 154         FILE * f;
 155         char dummydata[256];
 156         int rlen,flen;
 157         short int b_per_sec,num_channels,tag;
 158         char riffid[5],waveid[5],fmtid[5],dataid[5];
 159         int wav_frequency, wav_bits;
 160         int * ls;
 161         int * rs;
 162
 163         if((f=fopen(filename,"r"))==NULL)
 164                 return(0);
 165
 166         fread(riffid,1,4,f);
 167         riffid[4] = 0;
 168         fread(&rlen,1,4,f);
 169         fread(waveid,1,4,f);
 170         waveid[4] = 0;
 171
 172         if(strcmp(waveid,"WAVE"))
 173         {
 174                 fclose(f);
 175                 return(0);
 176         }
 177
 178         fread(fmtid,1,4,f);
 179         fmtid[4] = 0;
 180         flen=fget32(f);
 181
 182         if(flen>240)
 183                 flen=240;
 184
 185         fread(&tag,1,2,f);
 186
 187         num_channels=fget16(f);
 188         wav_frequency=fget32(f);
 189         b_per_sec=fget32(f);
 190
 191         wav_bits=fget16(f) / num_channels;
 192         wav_bits*=8;
 193
 194         fread(dummydata,1,(size_t)flen-14,f);
 195         fread(dataid,1,4,f);
 196         dataid[4] = 0;
 197
 198         *size=fget32(f);
 199         if(wav_bits==16) (*size)/=2;
 200         if(num_channels==2) (*size)/=2;
 201
 202         load_pcm_wave(f, size, wav_bits, num_channels,
 203                 wav_frequency, &ls, &rs);
 204
 205         fclose(f);
 206
 207         *lwave=ls;
 208         *rwave=rs;
 209
 210         return(1);
 211 }
 212
 213