#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <math.h>
#include <sys/soundcard.h>

int main(int argn, char *arg[]) {
  int i;
  int16_t sample1[48000*2*2];
  int16_t sample2[48000*2*2];
  u_int8_t *ptr1, *ptr2;
  int ret, out, req;
  int fd;
  int tmp;

  ptr1 = (u_int8_t *)sample1;
  ptr2 = (u_int8_t *)sample2;

  fd = open("/dev/dsp", O_WRONLY | O_NONBLOCK);
  tmp=0;     ioctl(fd, SNDCTL_DSP_RESET,      &tmp);
  tmp=2;     ioctl(fd, SNDCTL_DSP_STEREO,     &tmp);
  tmp=16;    ioctl(fd, SNDCTL_DSP_SAMPLESIZE, &tmp);
  tmp=48000; ioctl(fd, SNDCTL_DSP_SPEED,      &tmp);

  usleep(500000);

  for (i=0;i<48000*2;i++) {
    sample1[i*2  ]=20000.0*sin(2.0*M_PI*440.0*((double)i)/48000.0);
    sample1[i*2+1]=20000.0*sin(2.0*M_PI*445.0*((double)i)/48000.0);
  }

  for (i=0;i<48000*2;i++) {
    sample2[i*2  ]=20000.0*sin(2.0*M_PI*660.0*((double)i)/48000.0);
    sample2[i*2+1]=20000.0*sin(2.0*M_PI*665.0*((double)i)/48000.0);
  }

  // play the first tone
  out = 0; req = 48000*2*2*2;
  while (out!=req) {
    ret = write(fd, ptr1+out, req-out);
    if (ret!=-1) out += ret;
    usleep(10);
  }
 
  // wait for dac drain 
  do ioctl(fd, SNDCTL_DSP_GETODELAY, &tmp); while (tmp>0);

  // Wait more to be certain that it's drained
  usleep(500000);

  // Try to play the second tone
  out = 0; req = 48000*2*2*2;
  while (out!=req) {
    ret = write(fd, ptr2+out, req-out);
    if (ret!=-1) out += ret;
    usleep(10);
  }

  do ioctl(fd, SNDCTL_DSP_GETODELAY, &tmp); while (tmp>0);

  usleep(500000);

  close(fd);
  return 0;
}