ref: b2f339168bf5b666f96067daf4de4c9f07f51c92
dir: /src/sphere.c/
/*
* NIST Sphere file format handler.
*
* August 7, 2000
*
* Copyright (C) 2000 Chris Bagwell (cbagwell@sprynet.com)
*
*/
#include "st_i.h"
#include <math.h>
#include <string.h>
#include <errno.h>
/* Private data for sphere file */
typedef struct spherestuff {
char shorten_check[4];
st_size_t numSamples;
} *sphere_t;
/*
* Do anything required before you start reading samples.
* Read file header.
* Find out sampling rate,
* size and encoding of samples,
* mono/stereo/quad.
*/
static int st_spherestartread(ft_t ft)
{
sphere_t sphere = (sphere_t) ft->priv;
int rc;
char *buf;
char fldname[64], fldtype[16], fldsval[128];
int i;
int header_size, bytes_read;
long rate;
/* Needed for rawread() */
rc = st_rawstartread(ft);
if (rc)
return rc;
/* Magic header */
if (st_reads(ft, fldname, 8) == ST_EOF || strncmp(fldname, "NIST_1A", 7) != 0)
{
st_fail_errno(ft,ST_EHDR,"Sphere header does not begin with magic mord 'NIST_1A'");
return(ST_EOF);
}
if (st_reads(ft, fldsval, 8) == ST_EOF)
{
st_fail_errno(ft,ST_EHDR,"Error reading Sphere header");
return(ST_EOF);
}
/* Determine header size, and allocate a buffer large enough to hold it. */
sscanf(fldsval, "%d", &header_size);
buf = (char *)xmalloc(header_size);
/* Skip what we have read so far */
header_size -= 16;
if (st_reads(ft, buf, header_size) == ST_EOF)
{
st_fail_errno(ft,ST_EHDR,"Error reading Sphere header");
free(buf);
return(ST_EOF);
}
header_size -= (strlen(buf) + 1);
while (strncmp(buf, "end_head", 8) != 0)
{
if (strncmp(buf, "sample_n_bytes", 14) == 0 && ft->signal.size == -1)
{
sscanf(buf, "%63s %15s %d", fldname, fldtype, &i);
ft->signal.size = i;
}
if (strncmp(buf, "channel_count", 13) == 0 &&
ft->signal.channels == 0)
{
sscanf(buf, "%63s %15s %d", fldname, fldtype, &i);
ft->signal.channels = i;
}
if (strncmp(buf, "sample_coding", 13) == 0)
{
sscanf(buf, "%63s %15s %127s", fldname, fldtype, fldsval);
/* Only bother looking for ulaw flag. All others
* should be caught below by default PCM check
*/
if (ft->signal.encoding == ST_ENCODING_UNKNOWN &&
strncmp(fldsval,"ulaw",4) == 0)
{
ft->signal.encoding = ST_ENCODING_ULAW;
}
}
if (strncmp(buf, "sample_rate ", 12) == 0 &&
ft->signal.rate == 0)
{
sscanf(buf, "%53s %15s %ld", fldname, fldtype, &rate);
ft->signal.rate = rate;
}
if (strncmp(buf, "sample_byte_format", 18) == 0)
{
sscanf(buf, "%53s %15s %127s", fldname, fldtype, fldsval);
if (strncmp(fldsval,"01",2) == 0)
ft->signal.reverse_bytes = ST_IS_BIGENDIAN; /* Data is little endian. */
else if (strncmp(fldsval,"10",2) == 0)
ft->signal.reverse_bytes = ST_IS_LITTLEENDIAN; /* Data is big endian. */
}
if (st_reads(ft, buf, header_size) == ST_EOF)
{
st_fail_errno(ft,ST_EHDR,"Error reading Sphere header");
free(buf);
return(ST_EOF);
}
header_size -= (strlen(buf) + 1);
}
if (ft->signal.size == -1)
ft->signal.size = ST_SIZE_BYTE;
/* sample_coding is optional and is PCM if missing.
* This means encoding is signed if size = word or
* unsigned if size = byte.
*/
if (ft->signal.encoding == ST_ENCODING_UNKNOWN)
{
if (ft->signal.size == 1)
ft->signal.encoding = ST_ENCODING_UNSIGNED;
else
ft->signal.encoding = ST_ENCODING_SIGN2;
}
while (header_size)
{
bytes_read = st_readbuf(ft, buf, ST_SIZE_BYTE, header_size);
if (bytes_read == 0)
{
free(buf);
return(ST_EOF);
}
header_size -= bytes_read;
}
sphere->shorten_check[0] = 0;
/* Check first four bytes of data to see if it's shorten
* compressed or not.
*/
st_reads(ft, sphere->shorten_check, 4);
if (!strcmp(sphere->shorten_check,"ajkg"))
{
st_fail_errno(ft,ST_EFMT,"File uses shorten compression, cannot handle this.");
free(buf);
return(ST_EOF);
}
free(buf);
return (ST_SUCCESS);
}
/*
* Read up to len samples from file.
* Convert to signed longs.
* Place in buf[].
* Return number of samples read.
*/
static st_size_t st_sphereread(ft_t ft, st_sample_t *buf, st_size_t len)
{
sphere_t sphere = (sphere_t) ft->priv;
if (sphere->shorten_check[0])
{
/* TODO: put these 4 bytes into the buffer. Requires
* knowing how to process ulaw and all version of PCM data size.
*/
sphere->shorten_check[0] = 0;
}
return st_rawread(ft, buf, len);
}
static int st_spherestartwrite(ft_t ft)
{
int rc;
int x;
sphere_t sphere = (sphere_t) ft->priv;
if (!ft->seekable)
{
st_fail_errno(ft,ST_EOF,"File must be seekable for sphere file output");
return (ST_EOF);
}
switch (ft->signal.encoding)
{
case ST_ENCODING_ULAW:
case ST_ENCODING_SIGN2:
case ST_ENCODING_UNSIGNED:
break;
default:
st_fail_errno(ft,ST_EFMT,"SPHERE format only supports ulaw and PCM data.");
return(ST_EOF);
}
sphere->numSamples = 0;
/* Needed for rawwrite */
rc = st_rawstartwrite(ft);
if (rc)
return rc;
for (x = 0; x < 1024; x++)
{
st_writeb(ft, ' ');
}
return(ST_SUCCESS);
}
static st_size_t st_spherewrite(ft_t ft, const st_sample_t *buf, st_size_t len)
{
sphere_t sphere = (sphere_t) ft->priv;
sphere->numSamples += len; /* must later be divided by channels */
return st_rawwrite(ft, buf, len);
}
static int st_spherestopwrite(ft_t ft)
{
int rc;
char buf[128];
sphere_t sphere = (sphere_t) ft->priv;
long samples, rate;
rc = st_rawstopwrite(ft);
if (rc)
return rc;
if (st_seeki(ft, 0L, 0) != 0)
{
st_fail_errno(ft,errno,"Could not rewird output file to rewrite sphere header.");
return (ST_EOF);
}
st_writes(ft, "NIST_1A\n");
st_writes(ft, " 1024\n");
samples = sphere->numSamples/ft->signal.channels;
sprintf(buf, "sample_count -i %ld\n", samples);
st_writes(ft, buf);
sprintf(buf, "sample_n_bytes -i %d\n", ft->signal.size);
st_writes(ft, buf);
sprintf(buf, "channel_count -i %d\n", ft->signal.channels);
st_writes(ft, buf);
sprintf(buf, "sample_byte_format -s2 %s\n",
ft->signal.reverse_bytes != ST_IS_BIGENDIAN ? "10" : "01");
st_writes(ft, buf);
rate = ft->signal.rate;
sprintf(buf, "sample_rate -i %ld\n", rate);
st_writes(ft, buf);
if (ft->signal.encoding == ST_ENCODING_ULAW)
st_writes(ft, "sample_coding -s4 ulaw\n");
else
st_writes(ft, "sample_coding -s3 pcm\n");
st_writes(ft, "end_head\n");
return (ST_SUCCESS);
}
/* NIST Sphere File */
static const char *spherenames[] = {
"sph",
NULL
};
static st_format_t st_sphere_format = {
spherenames,
NULL,
0,
st_spherestartread,
st_sphereread,
st_rawstopread,
st_spherestartwrite,
st_spherewrite,
st_spherestopwrite,
st_format_nothing_seek
};
const st_format_t *st_sphere_format_fn(void)
{
return &st_sphere_format;
}