Voxifera/dsp.c

#include "vocal.h"

int init_dsp( char *device )  {
	int dsp, arg;

	if ((dsp=open( (device == NULL ? "/dev/dsp" : device), O_RDONLY)) < 0) {
		perror("open of sound device failed");
		return -1;
	}

	arg = AFMT_U8;

	if (ioctl(dsp, SNDCTL_DSP_SETFMT, &arg)<0)  {
		perror ("SNDCTL_DSP_SETFMT failed");
		return -1;
	}

	if (arg != AFMT_U8)  {
		perror ("sound device doesn't support AFMT_U8");
		return -1;
	}

	arg = SIZE;

	if (ioctl(dsp, SOUND_PCM_WRITE_BITS, &arg) == -1)  {
		perror("SOUND_PCM_WRITE_BITS ioctl failed");
		return -1;
	}

	if (arg != SIZE)  {
		perror("unable to set sample size");
		return -1;
	}

	arg = CHANNELS;
	
	if (ioctl(dsp, SOUND_PCM_WRITE_CHANNELS, &arg) == -1)  {
		perror("SOUND_PCM_WRITE_CHANNELS ioctl failed");
		return -1;
	}

	if (arg != CHANNELS)  {
		perror("unable to set number of channels");
		return -1;
	}

	arg = RATE;
	
	if (ioctl(dsp, SOUND_PCM_WRITE_RATE, &arg) == -1)  {
		perror("SOUND_PCM_WRITE_WRITE ioctl failed");
		return -1;
	}

	return dsp;
}