/* [<][>][^][v][top][bottom][index][help] */
DEFINITIONS
This source file includes following definitions.
- getWAVBlock
- wav_read
- wav_write
- wav_print
- wav_convert2mono
/* wav.c
Routines for handling .wav files
Part of the swftools package.
Copyright (c) 2001 Matthias Kramm <kramm@quiss.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "wav.h"
struct WAVBlock {
char id[5];
unsigned int size;
};
int getWAVBlock(FILE*fi, struct WAVBlock*block)
{
unsigned int size;
unsigned char b[4];
if(fread(block->id,1,4,fi)<4)
return 0;
block->id[4] = 0;
if(fread(b,1,4,fi)<4)
return 0;
block->size = b[0]|b[1]<<8|b[2]<<16|b[3]<<24;
/*printf("Chunk: [%c%c%c%c] (%d bytes)\n",
block->id[0],block->id[1],
block->id[2],block->id[3],
block->size);*/
return 1;
}
int wav_read(struct WAV*wav, const char* filename)
{
FILE*fi = fopen(filename, "rb");
unsigned char b[16];
long int filesize;
struct WAVBlock block;
long int pos;
if(!fi)
return 0;
fseek(fi, 0, SEEK_END);
filesize = ftell(fi);
fseek(fi, 0, SEEK_SET);
//printf("Filesize: %d\n", filesize);
if(!getWAVBlock (fi, &block))
{
fclose(fi);
return 0;
}
if(strncmp(block.id,"RIFF",4))
{
fprintf(stderr, "wav_read: not a WAV file\n");
fclose(fi);
return 0;
}
if(block.size + 8 < filesize)
fprintf(stderr, "wav_read: warning - more tags (%lu extra bytes)\n", filesize - block.size - 8);
if(block.size == filesize)
/* some buggy software doesn't generate the right tag length */
block.size = filesize - 8;
if(block.size + 8 > filesize)
fprintf(stderr, "wav_read: warning - short file (%lu bytes missing)\n", block.size + 8 - filesize);
if(fread(b, 1, 4, fi) < 4)
{
fclose(fi);
return 0;
}
if(strncmp((const char*)b, "WAVE", 4))
{
fprintf(stderr, "wav_read: not a WAV file (2)\n");
fclose(fi);
return 0;
}
do
{
getWAVBlock(fi, &block);
pos = ftell(fi);
if(!strncmp(block.id, "fmt ", 4))
{
if(fread(&b, 1, 16, fi)<16)
{
fclose(fi);
return 0;
}
wav->tag = b[0]|b[1]<<8;
wav->channels = b[2]|b[3]<<8;
wav->sampsPerSec = b[4]|b[5]<<8|b[6]<<16|b[7]<<24;
wav->bytesPerSec = b[8]|b[9]<<8|b[10]<<16|b[11]<<24;
wav->align = b[12]|b[13]<<8;
wav->bps = b[14]|b[15]<<8;
}
else
if (!strncmp(block.id, "LIST", 4))
{
// subchunk ICMT (comment) may exist
}
else
if (!strncmp(block.id, "data", 4))
{
int l;
wav->data = (unsigned char*)malloc(block.size);
if(!wav->data)
{
fprintf(stderr, "Out of memory (%d bytes needed)", block.size);
fclose(fi);
return 0;
}
l = fread(wav->data, 1, block.size, fi);
if(l<=0) {
fprintf(stderr, "Error: Couldn't read WAV data block\n");
fclose(fi);
return 0;
} else if(l < block.size)
{
fprintf(stderr, "Warning: data block of size %d is only %d bytes (%d bytes missing)\n", block.size, l, block.size-l);
wav->size = l;
} else {
wav->size = block.size;
}
}
pos+=block.size;
fseek(fi, pos, SEEK_SET);
}
while (pos < filesize);
fclose(fi);
return 1;
}
int wav_write(struct WAV*wav, const char*filename)
{
FILE*fi = fopen(filename, "wb");
char*b="RIFFWAVEfmt \x10\0\0\0data";
char c[16];
unsigned long int w32;
if(!fi)
return 0;
fwrite(b, 4, 1, fi);
w32=(/*fmt*/8+0x10+/*data*/8+wav->size);
c[0] = w32;
c[1] = w32>>8;
c[2] = w32>>16;
c[3] = w32>>24;
fwrite(c, 4, 1, fi);
fwrite(&b[4], 12, 1, fi);
c[0] = wav->tag;
c[1] = wav->tag>>8;
c[2] = wav->channels;
c[3] = wav->channels>>8;
c[4] = wav->sampsPerSec;
c[5] = wav->sampsPerSec>>8;
c[6] = wav->sampsPerSec>>16;
c[7] = wav->sampsPerSec>>24;
c[8] = wav->bytesPerSec;
c[9] = wav->bytesPerSec>>8;
c[10] = wav->bytesPerSec>>16;
c[11] = wav->bytesPerSec>>24;
c[12] = wav->align;
c[13] = wav->align>>8;
c[14] = wav->bps;
c[15] = wav->bps>>8;
fwrite(c, 16, 1, fi);
fwrite(&b[16], 4, 1, fi);
c[0] = wav->size;
c[1] = wav->size>>8;
c[2] = wav->size>>16;
c[3] = wav->size>>24;
fwrite(c,4,1,fi);
printf("writing %d converted bytes\n", wav->size);
fwrite(wav->data,wav->size,1,fi);
fclose(fi);
return 1;
}
void wav_print(struct WAV*wav)
{
printf("tag:%04x channels:%d samples/sec:%lu bytes/sec:%lu align:%d bits/sample:%d size:%d\n",
wav->tag, wav->channels, wav->sampsPerSec, wav->bytesPerSec,
wav->align, wav->bps, wav->size);
}
int wav_convert2mono(struct WAV*src, struct WAV*dest, int rate)
{
int samplelen=src->size/src->align;
int bps=src->bps;
double ratio;
double pos = 0;
int pos2 = 0;
int channels=src->channels;
int i;
int fill;
dest->sampsPerSec = rate;
dest->bps = 16;
dest->channels = 1;
dest->align = 2;
dest->tag = src->tag;
dest->bytesPerSec = dest->sampsPerSec*dest->align;
ratio = (double)dest->sampsPerSec/(double)src->sampsPerSec;
fill = (int)(ratio+1)*2;
dest->data = (unsigned char*)malloc((int)(samplelen*ratio*2)+128);
if(!dest->data)
return 0;
dest->size = (int)(samplelen*ratio)*2;
if(bps == 8) {
if(ratio <= 1) {
for(i=0; i<src->size; i+=channels) {
int pos2 = ((int)pos)*2;
dest->data[pos2] = 0;
dest->data[pos2+1] = src->data[i]+128;
pos += ratio;
}
} else {
for(i=0; i<src->size; i+=channels) {
int j;
int pos2 = ((int)pos)*2;
for(j=0;j<fill;j+=2) {
dest->data[pos2+j+0] = 0;
dest->data[pos2+j+1] = src->data[i]+128;
}
pos += ratio;
}
}
} else if(bps == 16) {
if(ratio <= 1) {
for(i=0; i<src->size/2; i+=channels) {
int pos2 = ((int)pos)*2;
dest->data[pos2+0]=src->data[i*2];
dest->data[pos2+1]=src->data[i*2+1];
pos += ratio;
}
} else {
for(i=0; i<src->size/2; i+=channels) {
int j;
int pos2 = ((int)pos)*2;
for(j=0;j<fill;j+=2) {
dest->data[pos2+j+0] = src->data[i*2];
dest->data[pos2+j+1] = src->data[i*2+1];
}
pos += ratio;
}
}
} else if(bps == 32) {
if(ratio <= 1) {
for(i=0; i<src->size/4; i+=channels) {
int pos2 = ((int)pos)*2;
dest->data[pos2+0]=src->data[i*4+2];
dest->data[pos2+1]=src->data[i*4+3];
pos += ratio;
}
} else {
for(i=0; i<src->size/4; i+=channels) {
int j;
int pos2 = ((int)pos)*2;
for(j=0;j<fill;j+=2) {
dest->data[pos2+j+0] = src->data[i*4+2];
dest->data[pos2+j+1] = src->data[i*4+3];
}
pos += ratio;
}
}
} else {
fprintf(stderr, "Unsupported bitspersample value: %d\n", bps);
}
return 1;
}