Category : C Source Code
Archive   : SOX.ZIP
Filename : WAV.C

 
Output of file : WAV.C contained in archive : SOX.ZIP
/*
* April 15, 1992
* Copyright 1992 Rick Richardson
* Copyright 1991 Lance Norskog And Sundry Contributors
* This source code is freely redistributable and may be used for
* any purpose. This copyright notice must be maintained.
* Lance Norskog And Sundry Contributors are not responsible for
* the consequences of using this software.
*/

/*
* Windows 3.0 .wav format driver
*/

#include "st.h"

/* Private data for .wav file */
typedef struct wavstuff {
long samples;
} *wav_t;

extern float volume, amplitude;
extern long summary, verbose;

/*
* Do anything required before you start reading samples.
* Read file header.
* Find out sampling rate,
* size and style of samples,
* mono/stereo/quad.
*/
wavstartread(ft)
ft_t ft;
{
wav_t wav = (wav_t) ft->priv;
char magic[4];
long len;

/* If you need to seek around the input file. */
if (0 && ! ft->seekable)
fail(".wav input file must be a file, not a pipe");

fread(magic, 4, 1, ft->fp);
if (strncmp("RIFF", magic, 4))
fail("Not a RIFF file");

len = rllong(ft);

fread(magic, 4, 1, ft->fp);
if (strncmp("WAVE", magic, 4))
fail("Not a WAVE file");

fread(magic, 4, 1, ft->fp);
if (strncmp("fmt ", magic, 4))
fail("Missing fmt spec");

len = rllong(ft);
switch (rlshort(ft))
{
case 1: ft->info.style = UNSIGNED; break;
default: fail("Don't understand format");
}
ft->info.channels = rlshort(ft);
ft->info.rate = rllong(ft);
rllong(ft); /* Average bytes/second */
rlshort(ft); /* Block align */
switch (rlshort(ft))
{
case 8: ft->info.size = BYTE; break;
case 16: ft->info.size = WORD; break;
case 32: ft->info.size = LONG; break;
default: fail("Don't understand size");
}
len -= 16;
while (len) getc(ft->fp);

fread(magic, 4, 1, ft->fp);
if (strncmp("data", magic, 4))
fail("Missing data portion");

wav->samples = rllong(ft);
}

/*
* Read up to len samples from file.
* Convert to signed longs.
* Place in buf[].
* Return number of samples read.
*/

wavread(ft, buf, len)
ft_t ft;
long *buf, len;
{
wav_t wav = (wav_t) ft->priv;
int done;

if (len > wav->samples) len = wav->samples;
if (len == 0) return 0;
done = rawread(ft, buf, len);
wav->samples -= len;
return done;
}

/*
* Do anything required when you stop reading samples.
* Don't close input file!
*/
wavstopread(ft)
ft_t ft;
{
}

wavstartwrite(ft)
ft_t ft;
{
wav_t wav = (wav_t) ft->priv;
int littlendian = 0;
char *endptr;

if (! ft->seekable)
fail("Output .wav file must be a file, not a pipe");

endptr = (char *) &littlendian;
*endptr = 1;
if (!littlendian) ft->swap = 1;

wav->samples = 0;
wavwritehdr(ft);
}

wavwritehdr(ft)
ft_t ft;
{
wav_t wav = (wav_t) ft->priv;
int samsize;
long datasize;

switch (ft->info.size)
{
case BYTE: samsize = 8; break;
case WORD: samsize = 16; break;
default:
case LONG: ft->info.size = LONG; samsize = 32; break;
}
ft->info.style = UNSIGNED;

datasize = samsize/8 * ft->info.channels * wav->samples;

fputs("RIFF", ft->fp);
wllong(ft, datasize + 8+16+12); /* Waveform chunk size: FIXUP(4) */
fputs("WAVE", ft->fp);
fputs("fmt ", ft->fp);
wllong(ft, (long)16); /* fmt chunk size */
wlshort(ft, 1); /* FormatTag: WAVE_FORMAT_PCM */
wlshort(ft, ft->info.channels);
wllong(ft, (long)ft->info.rate); /* SamplesPerSec */
/* Average Bytes/sec */
wllong(ft, (long)(ft->info.rate * ft->info.channels * samsize + 7) / 8);
/* nBlockAlign */
wlshort(ft, (ft->info.channels * samsize + 7) / 8);
wlshort(ft, samsize); /* BitsPerSample */

fputs("data", ft->fp);
wllong(ft, datasize); /* data chunk size: FIXUP(40) */
}

wavwrite(ft, buf, len)
ft_t ft;
long *buf, len;
{
wav_t wav = (wav_t) ft->priv;

wav->samples += len * ft->info.size;
rawwrite(ft, buf, len);
}

void
wavstopwrite(ft)
ft_t ft;
{
/* All samples are already written out. */
/* If file header needs fixing up, for example it needs the */
/* the number of samples in a field, seek back and write them here. */
wav_t wav = (wav_t) ft->priv;

if (!ft->seekable)
return;
if (fseek(ft->fp, 0L, 0) != 0)
fail("Can't rewind output file to rewrite .wav header.");
wavwritehdr(ft);
}


  3 Responses to “Category : C Source Code
Archive   : SOX.ZIP
Filename : WAV.C

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/