Mixer Information

mute.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/soundcard.h>
#include <errno.h>
#include <string.h>

#define EMPEG_MIXER_READ_FLAGS _IOR('m', 1, int)
#define EMPEG_MIXER_WRITE_FLAGS _IOW('m', 1, int)
#define EMPEG_MIXER_FLAG_MUTE (1<<0)

int main(int ac, char *av[])
{
    int mute = -1;
    int flags = 0;
    int fd = -1;
    
    while (*++av)
    {
	if(av[0][0] == '-')
	{
	    switch(av[0][1])
	    {
	    case 'm':
		mute = 1;
		break;
	    case 'u':
		mute = 0;
		break;
	    default:
		fprintf(stderr, "Usage: mute [-u|-m]\n");
		return 1;
	    }
	}
	else
	{
	    fprintf(stderr, "Usage: mute [-u|-m]\n");
	    return 1;
	}
    }

    fd = open("/dev/mixer", O_RDONLY);
    if (fd < 0)
    {
	fprintf(stderr, "Couldn't open /dev/mixer\n");
	return 2;
    }

    if (mute >= 0)
    {
	if (mute)
	    flags |= EMPEG_MIXER_FLAG_MUTE;
	if (ioctl(fd, EMPEG_MIXER_WRITE_FLAGS, &flags) < 0)
	    printf("Write mute ioctl failed: %s (%d)\n", strerror(errno), errno);
    }

    if (ioctl(fd, EMPEG_MIXER_READ_FLAGS, &flags) < 0)
	printf("Read mute ioctl failed: %s (%d)\n", strerror(errno), errno);
		

    if (flags & EMPEG_MIXER_FLAG_MUTE)
	printf("Output is currently muted.\n");
    else
	printf("Output is currently unmuted.\n");

    return 0;
}

mixersrc.c

# include <stdio.h>
# include <unistd.h>
# include <fcntl.h>
# include <sys/ioctl.h>
# include <sys/soundcard.h>

# define DEV_MIXER  "/dev/mixer"

/* The following definitions are from include/asm-arm/arch-sa1100/empeg.h
   in the beta9b kernel source */

# define EMPEG_MIXER_MAGIC 'm'

# define EMPEG_MIXER_READ_SOURCE _IOR(EMPEG_MIXER_MAGIC, 0, int)
# define EMPEG_MIXER_WRITE_SOURCE _IOW(EMPEG_MIXER_MAGIC, 0, int)

int main(int argc, char *argv[])
{
  int fd, opt, source = 0;
  char *source_str;

  while ((opt = getopt(argc, argv, "prl")) != -1) {
    switch (opt) {
    case 'p':
      source = SOUND_MASK_PCM;
      break;

    case 'r':
      source = SOUND_MASK_RADIO;
      break;

    case 'l':
      source = SOUND_MASK_LINE;
      break;

    default:
      fprintf(stderr, "Usage: %s [-p|-r|-l]\n", argv[0]);
      return 1;
    }
  }

  fd = open(DEV_MIXER, O_RDONLY);
  if (fd == -1) {
    perror(DEV_MIXER);
    return 2;
  }

  if (source) {
    if (ioctl(fd, EMPEG_MIXER_WRITE_SOURCE, &source) == -1) {
      perror("ioctl(EMPEG_MIXER_WRITE_SOURCE)");
      return 3;
    }
  }

  if (ioctl(fd, EMPEG_MIXER_READ_SOURCE, &source) == -1) {
    perror("ioctl(EMPEG_MIXER_READ_SOURCE)");
    return 4;
  }

  if (source & SOUND_MASK_PCM)
    source_str = "PCM";
  else if (source & SOUND_MASK_RADIO)
    source_str = "radio";
  else if (source & SOUND_MASK_LINE)
    source_str = "line";
  else
    source_str = "unknown";

  printf("%s source selected\n", source_str);

  if (close(fd) == -1) {
    perror("close");
    return 5;
  }

  return 0;
}

sam.c

# include <stdio.h>
# include <unistd.h>
# include <fcntl.h>
# include <sys/ioctl.h>
# include <sys/soundcard.h>

# define DEV_MIXER  "/dev/mixer"

/* The following definitions are from include/asm-arm/arch-sa1100/empeg.h
   in the beta10a kernel source */

# define EMPEG_MIXER_MAGIC 'm'

# define EMPEG_MIXER_SET_SAM _IOW(EMPEG_MIXER_MAGIC, 15, int)

int main(int argc, char *argv[])
{
  int fd, opt, sam = -1;

  while ((opt = getopt(argc, argv, "mu")) != -1) {
    switch (opt) {
    case 'm':
      sam = 1;
      break;

    case 'u':
      sam = 0;
      break;

    default:
      return 1;
    }
  }

  if (sam == -1) {
    fprintf(stderr, "Usage: %s {-u|-m}\n", argv[0]);
    return 1;
  }

  fd = open(DEV_MIXER, O_RDONLY);
  if (fd == -1) {
    perror(DEV_MIXER);
    return 2;
  }

  if (ioctl(fd, EMPEG_MIXER_SET_SAM, &sam) == -1) {
    perror("ioctl(EMPEG_MIXER_SET_SAM)");
    return 3;
  }

  printf("Soft Audio Mute %s\n", sam ? "enabled" : "disabled");

  if (close(fd) == -1) {
    perror("close");
    return 5;
  }

  return 0;
}