ref: 4a4ea33edbca5972a1ed8933cc3512c7302fa67a
dir: /src/sphere.c/
/*
* NIST Sphere file format handler.
*
* August 7, 2000
*
* Copyright (C) 2000 Chris Bagwell (cbagwell@sprynet.com)
*
*/
#include "sox_i.h"
#include <math.h>
#include <string.h>
#include <errno.h>
/* Private data for sphere file */
typedef struct spherestuff {
char shorten_check[4];
sox_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 startread(sox_format_t * ft)
{
sphere_t sphere = (sphere_t) ft->priv;
char *buf;
char fldname[64], fldtype[16], fldsval[128];
int i;
sox_size_t header_size, bytes_read;
long rate;
/* Magic header */
if (sox_reads(ft, fldname, 8) == SOX_EOF || strncmp(fldname, "NIST_1A", 7) != 0)
{
sox_fail_errno(ft,SOX_EHDR,"Sphere header does not begin with magic mord 'NIST_1A'");
return(SOX_EOF);
}
if (sox_reads(ft, fldsval, 8) == SOX_EOF)
{
sox_fail_errno(ft,SOX_EHDR,"Error reading Sphere header");
return(SOX_EOF);
}
/* Determine header size, and allocate a buffer large enough to hold it. */
sscanf(fldsval, "%u", &header_size);
buf = xmalloc(header_size);
/* Skip what we have read so far */
header_size -= 16;
if (sox_reads(ft, buf, header_size) == SOX_EOF)
{
sox_fail_errno(ft,SOX_EHDR,"Error reading Sphere header");
free(buf);
return(SOX_EOF);
}
header_size -= (strlen(buf) + 1);
while (strncmp(buf, "end_head", 8) != 0)
{
if (strncmp(buf, "sample_n_bytes", 14) == 0 && !ft->encoding.bits_per_sample)
{
sscanf(buf, "%63s %15s %d", fldname, fldtype, &i);
ft->encoding.bits_per_sample = i << 3;
}
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->encoding.encoding == SOX_ENCODING_UNKNOWN &&
strncmp(fldsval,"ulaw",4) == 0)
{
ft->encoding.encoding = SOX_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->encoding.reverse_bytes = SOX_IS_BIGENDIAN; /* Data is little endian. */
else if (strncmp(fldsval,"10",2) == 0)
ft->encoding.reverse_bytes = SOX_IS_LITTLEENDIAN; /* Data is big endian. */
}
if (sox_reads(ft, buf, header_size) == SOX_EOF)
{
sox_fail_errno(ft,SOX_EHDR,"Error reading Sphere header");
free(buf);
return(SOX_EOF);
}
header_size -= (strlen(buf) + 1);
}
if (!ft->encoding.bits_per_sample)
ft->encoding.bits_per_sample = 8;
/* sample_coding is optional and is PCM if missing.
* This means encoding is signed if size = word or
* unsigned if size = byte.
*/
if (ft->encoding.encoding == SOX_ENCODING_UNKNOWN)
{
if (ft->encoding.bits_per_sample == 8)
ft->encoding.encoding = SOX_ENCODING_UNSIGNED;
else
ft->encoding.encoding = SOX_ENCODING_SIGN2;
}
while (header_size)
{
bytes_read = sox_readbuf(ft, buf, header_size);
if (bytes_read == 0)
{
free(buf);
return(SOX_EOF);
}
header_size -= bytes_read;
}
sphere->shorten_check[0] = 0;
if (ft->seekable) {
/* Check first four bytes of data to see if it's shorten compressed. */
sox_ssize_t pos = sox_tell(ft);
sox_reads(ft, sphere->shorten_check, 4);
if (!strcmp(sphere->shorten_check,"ajkg")) {
sox_fail_errno(ft, SOX_EFMT, "File uses shorten compression, cannot handle this.");
free(buf);
return(SOX_EOF);
}
/* Can't just seek -4, as sox_reads has read 1-4 bytes */
sox_seeki(ft, pos, SEEK_SET);
}
free(buf);
return sox_rawstartread(ft);
}
static int startwrite(sox_format_t * ft)
{
int rc;
int x;
sphere_t sphere = (sphere_t) ft->priv;
if (!ft->seekable)
{
sox_fail_errno(ft,SOX_EOF,"File must be seekable for sphere file output");
return (SOX_EOF);
}
sphere->numSamples = 0;
/* Needed for rawwrite */
rc = sox_rawstartwrite(ft);
if (rc)
return rc;
for (x = 0; x < 1024; x++)
{
sox_writeb(ft, ' ');
}
return(SOX_SUCCESS);
}
static sox_size_t write_samples(sox_format_t * ft, const sox_sample_t *buf, sox_size_t len)
{
sphere_t sphere = (sphere_t) ft->priv;
sphere->numSamples += len; /* must later be divided by channels */
return sox_rawwrite(ft, buf, len);
}
static int stopwrite(sox_format_t * ft)
{
char buf[128];
sphere_t sphere = (sphere_t) ft->priv;
long samples, rate;
if (sox_seeki(ft, 0, 0) != 0)
{
sox_fail_errno(ft,errno,"Could not rewind output file to rewrite sphere header.");
return (SOX_EOF);
}
sox_writes(ft, "NIST_1A\n");
sox_writes(ft, " 1024\n");
samples = sphere->numSamples/ft->signal.channels;
sprintf(buf, "sample_count -i %ld\n", samples);
sox_writes(ft, buf);
sprintf(buf, "sample_n_bytes -i %d\n", ft->encoding.bits_per_sample >> 3);
sox_writes(ft, buf);
sprintf(buf, "channel_count -i %d\n", ft->signal.channels);
sox_writes(ft, buf);
sprintf(buf, "sample_byte_format -s2 %s\n",
ft->encoding.reverse_bytes != SOX_IS_BIGENDIAN ? "10" : "01");
sox_writes(ft, buf);
rate = ft->signal.rate;
sprintf(buf, "sample_rate -i %ld\n", rate);
sox_writes(ft, buf);
if (ft->encoding.encoding == SOX_ENCODING_ULAW)
sox_writes(ft, "sample_coding -s4 ulaw\n");
else
sox_writes(ft, "sample_coding -s3 pcm\n");
sox_writes(ft, "end_head\n");
return (SOX_SUCCESS);
}
SOX_FORMAT_HANDLER(sphere)
{
static char const * const names[] = {"sph", "nist", NULL};
static unsigned const write_encodings[] = {
SOX_ENCODING_SIGN2, 8, 16, 24, 32, 0,
SOX_ENCODING_UNSIGNED, 8, 16, 24, 32, 0,
SOX_ENCODING_ULAW, 8, 0,
0};
static sox_format_handler_t const handler = {
names, 0,
startread, sox_rawread, sox_rawstopread,
startwrite, write_samples, stopwrite,
NULL, write_encodings, NULL
};
return &handler;
}