ref: 876f21808513d24b82838b0558c71dce9a414f0e
dir: /src/cdr.c/
/*
* CD-R format handler
*
* David Elliott, Sony Microsystems - July 5, 1991
*
* Copyright 1991 David Elliott 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.
*
* This code automatically handles endianness differences
*
* cbagwell (cbagwell@sprynet.com) - 20 April 1998
*
* Changed endianness handling. Seemed to be reversed (since format
* is in big endian) and made it so that user could always override
* swapping no matter what endian machine they are one.
*
* Fixed bug were trash could be appended to end of file for certain
* endian machines.
*
*/
#include "st.h"
#define SECTORSIZE (2352 / 2)
/* Private data for SKEL file */
typedef struct cdrstuff {
LONG samples; /* number of samples written */
} *cdr_t;
/*
* Do anything required before you start reading samples.
* Read file header.
* Find out sampling rate,
* size and encoding of samples,
* mono/stereo/quad.
*/
int st_cdrstartread(ft)
ft_t ft;
{
int rc;
/* Needed because of rawread() */
rc = st_rawstartread(ft);
if (rc)
return rc;
/* CDR is in Big Endian format. Swap whats read in on */
/* Little Endian machines. */
if (ST_IS_LITTLEENDIAN)
{
ft->swap = ft->swap ? 0 : 1;
}
ft->info.rate = 44100L;
ft->info.size = ST_SIZE_WORD;
ft->info.encoding = ST_ENCODING_SIGN2;
ft->info.channels = 2;
ft->comment = NULL;
return(ST_SUCCESS);
}
/*
* Read up to len samples from file.
* Convert to signed longs.
* Place in buf[].
* Return number of samples read.
*/
LONG st_cdrread(ft, buf, len)
ft_t ft;
LONG *buf, len;
{
return st_rawread(ft, buf, len);
}
/*
* Do anything required when you stop reading samples.
* Don't close input file!
*/
int st_cdrstopread(ft)
ft_t ft;
{
/* Needed because of rawread() */
return st_rawstopread(ft);
}
int st_cdrstartwrite(ft)
ft_t ft;
{
cdr_t cdr = (cdr_t) ft->priv;
int rc;
/* CDR is in Big Endian format. Swap whats written out on */
/* Little Endian Machines. */
if (ST_IS_LITTLEENDIAN)
{
ft->swap = ft->swap ? 0 : 1;
}
/* Needed because of rawwrite() */
rc = st_rawstartwrite(ft);
if (rc)
return rc;
cdr->samples = 0;
ft->info.rate = 44100L;
ft->info.size = ST_SIZE_WORD;
ft->info.encoding = ST_ENCODING_SIGN2;
ft->info.channels = 2;
return(ST_SUCCESS);
}
LONG st_cdrwrite(ft, buf, len)
ft_t ft;
LONG *buf, len;
{
cdr_t cdr = (cdr_t) ft->priv;
cdr->samples += len;
return st_rawwrite(ft, buf, len);
}
/*
* A CD-R file needs to be padded to SECTORSIZE, which is in terms of
* samples. We write -32768 for each sample to pad it out.
*/
int st_cdrstopwrite(ft)
ft_t ft;
{
cdr_t cdr = (cdr_t) ft->priv;
int padsamps = SECTORSIZE - (cdr->samples % SECTORSIZE);
short zero;
int rc;
/* Flush buffer before writing anything else */
rc = st_rawstopwrite(ft);
if (rc)
return rc;
zero = 0;
if (padsamps != SECTORSIZE)
{
while (padsamps > 0) {
st_writew(ft, zero);
padsamps--;
}
}
return(ST_SUCCESS);
}