#include <sys/param.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/soundcard.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>

#define IOCOUNT		4096

static const char *opts = "i:mA:";

static const char *usage = 
    "**Input Sampling rate should be 32KHz and Sample format 16 bit signed\n\n"
    	"-i <path>		: Input filename (default: stdin)\n"
    	"-m			: Mono input\n"
	"-A <path>		: DSP device path (default: /dev/dsp0)";


const char *devpath = "/dev/dsp0";


int
main(int argc, char **argv)
{
	char abuf[4096], *ptr;
	int i, ch, infd, sndfd, mono;

	infd = 0;	
	mono = 0;

	while ( (ch = getopt(argc, argv, opts)) != -1) {
		switch (ch) {
		case 'i':
			if ( (infd = open(optarg, O_RDONLY)) == -1)
				err(errno, "Error opening %s", optarg);
			break;
		case 'm':
			mono = 1;
			break;
		case 'A':
			devpath = optarg;
			break;
		default:
			errx(EINVAL, "Invalid usage\n\n%s", usage);
		}
	}

	if ( (sndfd = open(devpath, O_RDWR)) == -1)
		err(errno, "Error opening audio device %s", devpath);

	i = 32000;
        if (ioctl(sndfd, SNDCTL_DSP_SPEED, &i) == -1)
                err(errno, "DSP speed ioctl error");

	i = AFMT_S16_LE;
	if (!mono)
		i |= AFMT_STEREO;

        if (ioctl(sndfd, SNDCTL_DSP_SETFMT, &i) == -1)
                err(errno, "DSP format ioctl error");
	
	while ( (i = read(infd, abuf, IOCOUNT))) {
		ptr = abuf;
		while (i) {
			ch = write(sndfd, ptr, i);
			if (ch > 0) {
				i -= ch;
				ptr += ch;
			} else if (ch < 0)
				err(errno, "Error writing to DSP");
		}
	}

	return 0;
}