/* This program is to test play and record features of Linux OS */
/* Also its a multithreaded program to test the DUPLEX capability */
# include <sys/ioctl.h>
# include <sys/wait.h>
# include <unistd.h>
# include <fcntl.h>
# include <pthread.h>
# include <stdlib.h>
# include <stdio.h>
# include <signal.h>
# include <errno.h>
# include <sys/soundcard.h>

/* Function Prototypes */

void* play(void*);
void* record(void*);
void sig_hnd();

/* Device Name */

# define DEVICE_NAME "/dev/dsp"

/* Thread Ids for PLay & Record */
pthread_t play_tid,record_tid;

/* Buffer & File Descriptors */

# define BUFF_SIZE	4096
int audio_fd,io_fd;
unsigned char audio_buffer[BUFF_SIZE];

void sig_hnd(int signo) 
	{
	  printf("\n Completed Recording...");
	  pthread_exit(0);
	  close(io_fd);
	  close(audio_fd);
	}

void main(void)
{
   /* Thread Status */
   void **status;
   /* Thread Attribute Declarations */
   pthread_attr_t attr;
   
   /* Opening the audio device for playing and recording (DUPLEX) */
   if((audio_fd = open(DEVICE_NAME,O_RDWR,0)) == -1 ) {
	/* Opening of device failed */
	perror(DEVICE_NAME);
	exit(errno);
     }
    pthread_attr_init(&attr);
    pthread_create(&play_tid,&attr,play,NULL); /* Play Thread Created */
    pthread_create(&record_tid,&attr,record,NULL); /* Record Thread Created */
    signal(SIGINT,sig_hnd);
    pthread_join(record_tid,status);
}

void* play(void* arg)
	{
	 int len;
	 /* Opening the input  File */
         if((io_fd = open("RAJEN.WAV",O_RDONLY,0644)) == -1){
                /* Opening of input file failed */
                perror("RAJEN.WAV");
                exit(errno);
         }
	 printf("\n Playing.....\n");
         while(read(io_fd,audio_buffer,512)){
         /* Reading from input file */
         if((len = write(audio_fd,audio_buffer,512)) == -1){
                /* Audio Device Output error */
                perror("Audio Output");
                exit(errno);
          }
         }/* End of while */
	 close(audio_fd);
	}

void* record(void* arg)
	{
	 int len;
	 /* Opening the output File */
	 if((io_fd = open("RAJ.WAV",O_APPEND|O_TRUNC|O_WRONLY|O_CREAT,0644)) == -1){
		/* Opening of output file failed */
		perror("RAJ.WAV");
		exit(errno);
	 }
	 printf("\n Recording....");
	 printf("\n Press Ctrl-C To End Recording...");

	 while(1){
	 /* Reading from audio Device */
	 if((len = read(audio_fd,audio_buffer,512)) == -1){
		/* Audio Device Read error */
		perror("Audio Read");
		exit(errno);
	  }
	 if((len = write(io_fd,audio_buffer,512)) == -1){
		/* File Write Error */
		perror("File Write");
		exit(errno);
	  }
	 }/* End of while */
	}