I am trying to access a microphone on the empeg. Naive as I am, I first tried it the way I would do it on my linux box. I checked SOUND_MIXER_READ_DEVMASK, which returns a bitmask which in turn tells the devices supported by the particular mixer.

if (ioctl(fd, SOUND_MIXER_READ_DEVMASK, &mask_mixer) == -1)
{
return(MIXER_ERR);
}

if (!(mask_mixer & SOUND_MASK_MIC))
{
fprintf(stderr, "No mic.\n");
return(MIXER_ERR);
}

No luck. Checking the source I found this comment in empeg.h:
/* Sound IOCTLs */
/* Make use of the bitmasks in soundcard.h, we only support.
* PCM, RADIO and LINE. */

So how can I check for a mic and more imporantly set it as the active recording channel?
Do I use the EMPEG_AUDIOIN_*? And if, is there example code somewhere maybe?