#include <sys/types.h>
#include <sys/stat.h>
#include <sys/soundcard.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>

#include "vorbis/codec.h"
#include "vorbisfile.h"

int setup_dsp(int fd,int rate, int channels);


char pcmout[4096]; // 4KB buffer to hold decoded PCM data.
int dev_fd;

int main(int argc, char **argv)
{
	OggVorbis_File vf;
	int eof=0;
	int current_section;
	FILE *infile,*outfile;

	if(argc<2)
	{
		printf("supply file arguement\n");
		exit(0);
	}

	if ( (dev_fd = open("/dev/dsp",O_WRONLY)) == -1 ) 
	{
		perror("open /dev/dsp");
		return -1;
	}

	infile=fopen(argv[1],"r");
	
	if(infile==NULL)
	{
		perror("fopen");
		exit(-1);
	}   

	if(ov_open(infile, &vf, NULL, 0) < 0) 
	{
		fprintf(stderr,"Input does not appear to be an Ogg bitstream.\n");
		exit(1);
	}
	
	char **ptr=ov_comment(&vf,-1)->user_comments;
	vorbis_info *vi=ov_info(&vf,-1);
	while(*ptr)
	{
		fprintf(stderr,"%s\n",*ptr);
		++ptr;
	}

	fprintf(stderr,"\nBitstream is %d channel, %ldHz\n",vi->channels,vi->rate);
	fprintf(stderr,"\nDecoded length: %ld samples\n",(long)ov_pcm_total(&vf,-1));
	fprintf(stderr,"Encoded by: %s\n\n",ov_comment(&vf,-1)->vendor);
  
	if(setup_dsp(dev_fd,vi->rate,vi->channels-1))
	{
		printf("dsp setup error.aborting\n");
		exit(-1);
	}

	int count=0;
	
	while(!eof)
	{
		long ret=ov_read(&vf,pcmout,sizeof(pcmout),0,2,1,&current_section);
		if (ret == 0)
		{
			/* EOF */
			eof=1;
		}
		else if (ret < 0)
		{
	      		/* error in the stream.  Not a problem, just reporting it in
			case we (the app) cares.  In this case, we don't. */
		}
		else 
		{
			printf("Writing %d bytes for the %d time.\n",ret,++count);
			write(dev_fd,pcmout,ret);
		}
	}

	ov_clear(&vf);
	fclose(infile);
	
	if (ioctl(dev_fd, SNDCTL_DSP_SYNC) == -1) 
	{
    		perror("ioctl sync");
		return errno;
	}
	close(dev_fd);
	fprintf(stderr,"Done.\n");
	return(0);
}

int setup_dsp(int handle,int rate, int channels)
{
	int format;

	if ( ioctl(handle, SNDCTL_DSP_STEREO,&channels) == -1 ) 
	{
		perror("ioctl stereo");
		return errno;
	}
	
	format=AFMT_U8;
	if ( ioctl(handle, SNDCTL_DSP_SETFMT,&format) == -1 )
	{
		perror("ioctl format");
		return errno;
	}
	
	if ( ioctl(handle, SNDCTL_DSP_SPEED,&rate) == -1 )
	{
		perror("ioctl sample rate");
		return errno;
	}
	
	return 0;
}