#include <stdio.h>
#include <stdlib.h>
#include <alsa/asoundlib.h>

int main(int argc, char *argv[]) {
  struct snd_mixer_selem_regopt smixer_options;
  int err, ival;
  char card[64] = "default";
  long lval;
  static snd_mixer_t *handle = NULL;
  snd_mixer_elem_t *elem,*elemLFE;   
  snd_mixer_selem_id_t *sid;


  if ((err = snd_mixer_open(&handle, 0)) < 0) {
    error("Mixer %s open error: %s\n", card, snd_strerror(err));
    return err;
  }
  if ((err = snd_mixer_attach(handle, card)) < 0) {
    error("Mixer attach %s error: %s", card, snd_strerror(err));
    snd_mixer_close(handle);
    handle = NULL;
    return err;
  }
  if ((err = snd_mixer_selem_register(handle, NULL, NULL)) < 0) {
    error("Mixer register error: %s", snd_strerror(err));
    snd_mixer_close(handle);
    handle = NULL;
    return err;
  }
  if ((err = snd_mixer_load(handle)) < 0) {
    error("Mixer %s load error: %s", card, snd_strerror(err));
    snd_mixer_close(handle);
    handle = NULL;
    return err;
  }

  snd_mixer_selem_id_alloca(&sid);
  snd_mixer_selem_id_set_index(sid, 0);

  snd_mixer_selem_id_set_name(sid, "Master");
  elem = snd_mixer_find_selem(handle, sid);

  snd_mixer_selem_id_set_name(sid, "LFE");
  elemLFE = snd_mixer_find_selem(handle, sid);
 
  for (;;) {
    snd_mixer_wait(handle,-1);
    snd_mixer_handle_events(handle);

    snd_mixer_selem_get_playback_volume(elem, 1, &lval);
    snd_mixer_selem_set_playback_volume(elemLFE, 0, lval);

    snd_mixer_selem_get_playback_switch(elem, 1, &ival);
    snd_mixer_selem_set_playback_switch(elemLFE, 0, ival);
  }
  snd_mixer_close(handle);
  snd_mixer_free(handle);
  return(0);
}