lib/wav.c

   1 /* wav.c
   2    Routines for handling .wav files
   3
   4    Part of the swftools package.
   5
   6    Copyright (c) 2001 Matthias Kramm <kramm@quiss.org>
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25 #include "wav.h"
  26
  27 struct WAVBlock {
  28     char id[5];
  29     unsigned int size;
  30 };
  31
  32 int getWAVBlock(FILE*fi, struct WAVBlock*block)
  33 {
  34     unsigned int size;
  35     unsigned char b[4];
  36     if(fread(block->id,1,4,fi)<4)
  37         return 0;
  38     block->id[4] = 0;
  39     if(fread(b,1,4,fi)<4)
  40         return 0;
  41     block->size = b[0]|b[1]<<8|b[2]<<16|b[3]<<24;
  42     /*printf("Chunk: [%c%c%c%c] (%d bytes)\n",
  43             block->id[0],block->id[1],
  44             block->id[2],block->id[3],
  45             block->size);*/
  46     return 1;
  47 }
  48
  49 int wav_read(struct WAV*wav, const char* filename)
  50 {
  51     FILE*fi = fopen(filename, "rb");
  52     unsigned char b[16];
  53     long int filesize;
  54     struct WAVBlock block;
  55     long int pos;
  56
  57     if(!fi)
  58         return 0;
  59     fseek(fi, 0, SEEK_END);
  60     filesize = ftell(fi);
  61     fseek(fi, 0, SEEK_SET);
  62
  63     //printf("Filesize: %d\n", filesize);
  64
  65     if(!getWAVBlock (fi, &block))
  66     {
  67         fclose(fi);
  68         return 0;
  69     }
  70     if(strncmp(block.id,"RIFF",4))
  71     {
  72         fprintf(stderr, "wav_read: not a WAV file\n");
  73         fclose(fi);
  74         return 0;
  75     }
  76     if(block.size + 8 < filesize)
  77         fprintf(stderr, "wav_read: warning - more tags (%lu extra bytes)\n", filesize - block.size - 8);
  78
  79     if(block.size == filesize)
  80         /* some buggy software doesn't generate the right tag length */
  81         block.size = filesize - 8;
  82
  83     if(block.size + 8 > filesize)
  84         fprintf(stderr, "wav_read: warning - short file (%lu bytes missing)\n", block.size + 8 -  filesize);
  85     if(fread(b, 1, 4, fi) < 4)
  86     {
  87         fclose(fi);
  88                 return 0;
  89     }
  90     if(strncmp((const char*)b, "WAVE", 4))
  91     {
  92         fprintf(stderr, "wav_read: not a WAV file (2)\n");
  93         fclose(fi);
  94                 return 0;
  95         }
  96
  97     do
  98     {
  99         getWAVBlock(fi, &block);
 100         pos = ftell(fi);
 101         if(!strncmp(block.id, "fmt ", 4))
 102         {
 103             if(fread(&b, 1, 16, fi)<16)
 104             {
 105                 fclose(fi);
 106                 return 0;
 107             }
 108             wav->tag = b[0]|b[1]<<8;
 109             wav->channels = b[2]|b[3]<<8;
 110             wav->sampsPerSec = b[4]|b[5]<<8|b[6]<<16|b[7]<<24;
 111             wav->bytesPerSec = b[8]|b[9]<<8|b[10]<<16|b[11]<<24;
 112             wav->align = b[12]|b[13]<<8;
 113             wav->bps = b[14]|b[15]<<8;
 114         }
 115         else
 116             if (!strncmp(block.id, "LIST", 4))
 117             {
 118         // subchunk ICMT (comment) may exist
 119             }
 120             else
 121                 if (!strncmp(block.id, "data", 4))
 122                 {
 123                     int l;
 124                     wav->data = (unsigned char*)malloc(block.size);
 125                     if(!wav->data)
 126                     {
 127                         fprintf(stderr, "Out of memory (%d bytes needed)", block.size);
 128                         fclose(fi);
 129                         return 0;
 130                     }
 131                     l = fread(wav->data, 1, block.size, fi);
 132                     if(l<=0) {
 133                         fprintf(stderr, "Error: Couldn't read WAV data block\n");
 134                         fclose(fi);
 135                         return 0;
 136                     } else if(l < block.size)
 137                     {
 138                         fprintf(stderr, "Warning: data block of size %d is only %d bytes (%d bytes missing)\n", block.size, l, block.size-l);
 139                         wav->size = l;
 140                     } else {
 141                         wav->size = block.size;
 142                     }
 143                 }
 144                 pos+=block.size;
 145                 fseek(fi, pos, SEEK_SET);
 146     }
 147     while (pos < filesize);
 148     fclose(fi);
 149     return 1;
 150 }
 151
 152 int wav_write(struct WAV*wav, const char*filename)
 153 {
 154     FILE*fi = fopen(filename, "wb");
 155     char*b="RIFFWAVEfmt \x10\0\0\0data";
 156     char c[16];
 157     unsigned long int w32;
 158     if(!fi)
 159         return 0;
 160     fwrite(b, 4, 1, fi);
 161     w32=(/*fmt*/8+0x10+/*data*/8+wav->size);
 162     c[0] = w32;
 163     c[1] = w32>>8;
 164     c[2] = w32>>16;
 165     c[3] = w32>>24;
 166     fwrite(c, 4, 1, fi);
 167     fwrite(&b[4], 12, 1, fi);
 168     c[0] = wav->tag;
 169     c[1] = wav->tag>>8;
 170     c[2] = wav->channels;
 171     c[3] = wav->channels>>8;
 172     c[4] = wav->sampsPerSec;
 173     c[5] = wav->sampsPerSec>>8;
 174     c[6] = wav->sampsPerSec>>16;
 175     c[7] = wav->sampsPerSec>>24;
 176     c[8] = wav->bytesPerSec;
 177     c[9] = wav->bytesPerSec>>8;
 178     c[10] = wav->bytesPerSec>>16;
 179     c[11] = wav->bytesPerSec>>24;
 180     c[12] = wav->align;
 181     c[13] = wav->align>>8;
 182     c[14] = wav->bps;
 183     c[15] = wav->bps>>8;
 184     fwrite(c, 16, 1, fi);
 185     fwrite(&b[16], 4, 1, fi);
 186     c[0] = wav->size;
 187     c[1] = wav->size>>8;
 188     c[2] = wav->size>>16;
 189     c[3] = wav->size>>24;
 190     fwrite(c,4,1,fi);
 191     printf("writing %d converted bytes\n", wav->size);
 192     fwrite(wav->data,wav->size,1,fi);
 193     fclose(fi);
 194     return 1;
 195 }
 196
 197 void wav_print(struct WAV*wav)
 198 {
 199     printf("tag:%04x channels:%d samples/sec:%lu bytes/sec:%lu align:%d bits/sample:%d size:%d\n",
 200             wav->tag, wav->channels, wav->sampsPerSec, wav->bytesPerSec,
 201             wav->align, wav->bps, wav->size);
 202 }
 203
 204 int wav_convert2mono(struct WAV*src, struct WAV*dest, int rate)
 205 {
 206     int samplelen=src->size/src->align;
 207     int bps=src->bps;
 208     double ratio;
 209     double pos = 0;
 210     int pos2 = 0;
 211     int channels=src->channels;
 212     int i;
 213     int fill;
 214
 215     dest->sampsPerSec = rate;
 216     dest->bps = 16;
 217     dest->channels = 1;
 218     dest->align = 2;
 219     dest->tag = src->tag;
 220     dest->bytesPerSec = dest->sampsPerSec*dest->align;
 221
 222     ratio = (double)dest->sampsPerSec/(double)src->sampsPerSec;
 223     fill = (int)(ratio+1)*2;
 224
 225     dest->data = (unsigned char*)malloc((int)(samplelen*ratio*2)+128);
 226     if(!dest->data)
 227         return 0;
 228     dest->size = (int)(samplelen*ratio)*2;
 229
 230     if(bps == 8) {
 231         if(ratio <= 1) {
 232             for(i=0; i<src->size; i+=channels) {
 233                 int pos2 = ((int)pos)*2;
 234                 dest->data[pos2] = 0;
 235                 dest->data[pos2+1] = src->data[i]+128;
 236                 pos += ratio;
 237             }
 238         } else {
 239             for(i=0; i<src->size; i+=channels) {
 240                 int j;
 241                 int pos2 = ((int)pos)*2;
 242                 for(j=0;j<fill;j+=2) {
 243                     dest->data[pos2+j+0] = 0;
 244                     dest->data[pos2+j+1] = src->data[i]+128;
 245                 }
 246                 pos += ratio;
 247             }
 248         }
 249     } else if(bps == 16) {
 250         if(ratio <= 1) {
 251             for(i=0; i<src->size/2; i+=channels) {
 252                 int pos2 = ((int)pos)*2;
 253                 dest->data[pos2+0]=src->data[i*2];
 254                 dest->data[pos2+1]=src->data[i*2+1];
 255                 pos += ratio;
 256             }
 257         } else {
 258             for(i=0; i<src->size/2; i+=channels) {
 259                 int j;
 260                 int pos2 = ((int)pos)*2;
 261                 for(j=0;j<fill;j+=2) {
 262                     dest->data[pos2+j+0] = src->data[i*2];
 263                     dest->data[pos2+j+1] = src->data[i*2+1];
 264                 }
 265                 pos += ratio;
 266             }
 267         }
 268     } else if(bps == 32) {
 269         if(ratio <= 1) {
 270             for(i=0; i<src->size/4; i+=channels) {
 271                 int pos2 = ((int)pos)*2;
 272                 dest->data[pos2+0]=src->data[i*4+2];
 273                 dest->data[pos2+1]=src->data[i*4+3];
 274                 pos += ratio;
 275             }
 276         } else {
 277             for(i=0; i<src->size/4; i+=channels) {
 278                 int j;
 279                 int pos2 = ((int)pos)*2;
 280                 for(j=0;j<fill;j+=2) {
 281                     dest->data[pos2+j+0] = src->data[i*4+2];
 282                     dest->data[pos2+j+1] = src->data[i*4+3];
 283                 }
 284                 pos += ratio;
 285             }
 286         }
 287     } else {
 288         fprintf(stderr, "Unsupported bitspersample value: %d\n", bps);
 289     }
 290     return 1;
 291 }
 292
 293