This is osrconv.c in view mode; [Download] [Up]
/* SRCONV - program for converting sampling rates by integer ratios
*
* Input/output data is 32-bit floating point binary,
* and the user must supply an FIR digital filter as
* designed by the fir program. The subroutines called
* are taken from SRCONV in the IEEE Programs for Digital
* Signal Processing package.
* jos : 22-aug-80
* frm : 18-dec-80
*/
# include <carl/paths.h>
# include <carl/carl.h>
# include <carl/sndio.h>
# include <carl/josprogs.h>
# define NDAT 256 /* number of data samples to read per call */
# define NCMAX 256 /* number of filter coeficients maximum */
/* CHANGE THE FOLLOWING LINE OF CODE TO POINT TO DEFAULT FILTER HOME */
# define FLTHOME(name) libdir(srconv/name) /* for default filters */
char progname[] = "srconv";
main(argc,argv)
char *argv[];
{
extern char *xalloc();
int i, begsamp, nsamples, nsi, nso, nread;
int n, no; /* for the digital filter */
char fname[NAMSIZ], dfname[NAMSIZ], ldfname[NAMSIZ];
float coef[NCMAX], oc[NCMAX];
int l, m, q, nc, nq, ni, ierr; /* for the converter */
int nx,ny,ndata;
float *qbuf, *cofs, *bufm, *bufl;
int *ictr;
int sdiv;
float r;
/* read command line parameters and parameter files here */
if (argc >= 3) {
l = atoi(argv[1]);
m = atoi(argv[2]);
}
else {
l = inint(l = 2, "Interpolation factor l");
m = inint(m = 3, "Decimation factor m");
}
/* Here the common factors of l and m should be canceled out */
if ((l <= 0) || (m <= 0))
err("bad parameters");
if ((l == 1) && (m == 1))
err("bad parameters");
if ((((l % m) == 0) && (m != 1)) || (((m % l) == 0) && (l != 1)))
err("bad parameters");
/* get the filter */
sdiv = MAX(l, m); /* divisor of srate/2 for fir cutoff */
r = 0.5 / sdiv; /* fir cutoff value for srate = 1 */
strcpy(dfname, catm(FLTHOME(d), itoc(sdiv), ".flt", NULL));
strcpy(ldfname, catm(FLTHOME(ld), itoc(sdiv), ".flt", NULL));
if (argc >= 4) {
strcpy(fname, argv[3]);
if (argv[3][0] == '%')
strcpy(fname, dfname);
if (argv[3][1] == '%')
strcpy(fname, ldfname);
}
else {
fname[0] = NULLC; /* Force getflt to prompt for file */
fprintf(stderr,
"srconv: need a lowpass filter with cutoff at srate/(2*%d)\n",sdiv);
fprintf(stderr,
"srconv: for a sampling rate of one, fir stopband begins at %f\n",r);
}
if (! getflt(fname, dfname, NCMAX, &n, &no, coef, oc))
exit(0);
if (n < 2)
err("cannot use a filter with no zeros.");
if (no =! 1)
err("cannot use filter with poles, only FIR (use fir program)");
/* Converter parameters: */
q = ((n - 1) / l) + 1;
nc = l * q;
nq = 2 * q;
for (i = 0; i <= (n - 1) / 2; i++)
coef[i] = coef[i + n / 2]; /* need right wing */
for (i = (n + 1) / 2; i < n; i++)
coef[i] = 0; /* just in case */
qbuf = (float *) xalloc(2 * q * sizeof(float));
cofs = (float *) xalloc(nc * sizeof(float));
ni = 2 * l;
ictr = (int *) xalloc(ni * sizeof(int));
srinit_(&m, &l, qbuf, &nq, coef, &n, cofs, &nc, ictr, &ni, &ierr);
switch(ierr) {
case 0:
break;
case -1:
err("qbuf (nq) too small");
case -2:
err("cofs (nc) too small");
break;
case -3:
err("ictr (2*l) too small");
break;
default:
err("srinit returned a garbage error code");
break;
}
/* set up io buffers */
ndata = NDAT;
nx = ndata * m;
ny = ndata * l;
bufm = (float *) xalloc(nx * sizeof(float));
bufl = (float *) xalloc(ny * sizeof(float));
/* getio(&infile, &outfile, "float.dat", "newsr.dat"); */
begsamp = 0;
nsi = nso = 0;
procomsr(stdin, stdout, (double) l / (double) m);
do {
nread = fgetfbuf(bufm, nx, stdin);
srconv_(bufm, bufl, &ndata, qbuf, cofs, ictr); /* Conversion */
fputfbuf(bufl, ny, stdout);
nsi += nread;
nso += ny;
} while (nread == nx);
}
/*
* change the sample rate in the property
* list.
*/
procomsr(inp, outp, srchange)
FILE *inp, *outp;
double srchange;
{
extern PROP *getheader();
extern char *getprop();
char *srate, bsrate[40];
double osrate;
(void) getheader(inp);
if ((srate = getprop(inp, H_SRATE)) == NULL)
return;
if (sscanf(srate, "%f", &osrate) != 1)
return;
sprintf(bsrate, "%g", osrate * srchange);
addprop(outp, H_SRATE, bsrate);
}
char *
xalloc(n) {
extern char *malloc();
char *cp;
if ((cp = malloc(n)) == NULL) {
fprintf(stderr, "srconv: ");
perror("malloc");
exit(1);
}
return(cp);
}
err(msg)
char *msg;
{
extern char progname[];
fprintf(stderr, "%s: ", progname);
fprintf(stderr, "%s\n", msg);
exit(1);
}
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.