mirror of
https://github.com/thestk/stk
synced 2026-01-12 20:41:52 +00:00
100 lines
2.2 KiB
C++
100 lines
2.2 KiB
C++
/******************************************/
|
|
/*
|
|
Example program for realtime input/output
|
|
by Gary P. Scavone, 2000
|
|
|
|
This program reads N channels of realtime
|
|
audio input for a specified amount of time
|
|
and immediately play them back in realtime
|
|
(duplex mode). This program also demonstrates
|
|
the use of FIFO scheduling priority. To be
|
|
run with such priority, the program must be
|
|
set suid (chmod +s) and owned by root.
|
|
*/
|
|
/******************************************/
|
|
|
|
#include "RtDuplex.h"
|
|
|
|
#if !defined(__OS_Win_)
|
|
#include <sched.h>
|
|
#endif
|
|
|
|
void usage(void) {
|
|
/* Error function in case of incorrect command-line
|
|
argument specifications
|
|
*/
|
|
printf("\nuseage: ioN N time \n");
|
|
printf(" where N = number of channels,\n");
|
|
printf(" and time = the amount of time to record (in seconds).\n\n");
|
|
exit(0);
|
|
}
|
|
|
|
int
|
|
main(int argc, char *argv[])
|
|
{
|
|
int i=0;
|
|
|
|
// minimal command-line checking
|
|
if (argc != 3) usage();
|
|
|
|
int chans = (int) atoi(argv[1]);
|
|
float time = atof(argv[2]);
|
|
float sample_rate = SRATE;
|
|
MY_FLOAT *inSamples;
|
|
MY_FLOAT *lastSamples;
|
|
|
|
// allocate the lastSamples array
|
|
lastSamples = (MY_FLOAT *) new MY_FLOAT[chans];
|
|
for (i=0; i<chans; i++)
|
|
lastSamples[i] = 0.0;
|
|
|
|
// Define and open the realtime duplex device
|
|
RtDuplex *inout;
|
|
try {
|
|
inout = new RtDuplex(chans, sample_rate);
|
|
}
|
|
catch (StkError& m) {
|
|
m.printMessage();
|
|
exit(0);
|
|
}
|
|
|
|
#if !defined(__OS_Win_)
|
|
// set schedulling priority to SCHED_FIFO
|
|
struct sched_param p;
|
|
int min, max, priority;
|
|
|
|
if (!getuid() || !geteuid()) {
|
|
min=sched_get_priority_min(SCHED_FIFO);
|
|
max=sched_get_priority_max(SCHED_FIFO);
|
|
priority=min+(max-min)/2;
|
|
p.sched_priority=priority;
|
|
if (sched_setscheduler(0, SCHED_FIFO, &p)==-1) {
|
|
fprintf(stderr, "\ncould not activate scheduling with priority %d\n", priority);
|
|
}
|
|
seteuid(getuid());
|
|
}
|
|
#endif
|
|
|
|
// Here's the runtime loop
|
|
|
|
int j=0;
|
|
int samples = (int) (time*SRATE);
|
|
while (i<samples) {
|
|
inSamples = inout->mtick(lastSamples);
|
|
for (int k=0; k<chans; k++)
|
|
lastSamples[k] = inSamples[k];
|
|
i++;
|
|
#if !defined(__OS_Win_)
|
|
j++;
|
|
if (j>=256) {
|
|
sched_yield();
|
|
j = 0;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
// Clean up
|
|
delete inout;
|
|
delete [] lastSamples;
|
|
}
|