SNDCTL_DSP_SETFMT
case SNDCTL_DSP_SETFMT: /* sets _one_ format */
#define SNDCTL_DSP_SAMPLESIZE SNDCTL_DSP_SETFMT
#define SOUND_PCM_WRITE_BITS SNDCTL_DSP_SETFMT
#define SOUND_PCM_SETFMT SNDCTL_DSP_SETFMT
if (ioctl(fd, SNDCTL_DSP_SETFMT, &fmt, sizeof(fmt)) < 0)