//i<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<USING MMAP>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.

#include<stdio.h>

#include<alsa/asoundlib.h>

#include<fcntl.h>

#include<unistd.h>

#include<sys/time.h>

int main()

{

const snd_pcm_channel_area_t *areas;

int size;

unsigned char *buffer;

char *pcm_name;

unsigned int rate = 44100;

int chan;

int rc;

unsigned int val;

char check;

int pcmreturn;

//Set PCM stream and handle

snd_pcm_t *pcm_handle;

snd_pcm_stream_t stream = SND_PCM_STREAM_PLAYBACK;

//Set HARDWARE parameters

snd_pcm_hw_params_t *hwparams;

//pcm_name = (char *)malloc(10);

pcm_name = "plughw:0,0";

//allocate memory for hardware

if(snd_pcm_hw_params_malloc(&hwparams)<0)

{

fprintf(stderr,"No memory allocated for hardware");

return(-1);

}

if (snd_pcm_open(&pcm_handle, pcm_name, stream, 0) < 0) {

fprintf(stderr, "Error opening PCM device %s\n", pcm_name);

return(-1);

}

//INITIALIZE HARDWARE WITH CONFIGURATION OF THE SOUNDCARD

if(snd_pcm_hw_params_any(pcm_handle,hwparams)<0)

{

fprintf(stderr,"The hardware device cannot be configured\n");

}

//SET FORMAT TO 16 BIT LITTLE ENDIAN

snd_pcm_hw_params_set_format(pcm_handle,hwparams,SND_PCM_FORMAT_S16_LE);

/* Two channels (stereo) */

snd_pcm_hw_params_set_channels(pcm_handle,hwparams,2);

/* 44100 bits/second sampling rate (CD quality) */

if (snd_pcm_hw_params_set_access(pcm_handle, hwparams, SND_PCM_ACCESS_MMAP_INTERLEAVED) < 0) {

fprintf(stderr, "Error setting access.\n");

return(-1);

}

//SETTING RATE ie SAMPLING FREQUENCY

snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, &rate, 0);

//SETTING HARDWARE PARAMETERS

if(rc=(snd_pcm_hw_params(pcm_handle,hwparams))<0)

{

fprintf(stderr,"\nCannot set hardware parameters\n");

return -1;

}

//snd_pcm_uframes_t periodsize = 8192;

snd_pcm_uframes_t frames,offset ;//OF TYPE UNSIGNED LONG

snd_pcm_sframes_t commitres;

frames =32;

//SETTING SOME MORE PARAMETERS

size = frames*4;

//SETTING BUFFER SIZE

/*if (snd_pcm_hw_params_set_buffer_size(pcm_handle, hwparams, (periodsize*2)>>2) < 0) {

fprintf(stderr, "Error setting buffersize.\n");

return(-1);

}

*/

int first=0;;

int err;

snd_pcm_sframes_t avail = snd_pcm_avail_update(pcm_handle);

printf("\nNumber of frames available is : %d \n",(int)avail);

//-------------------------------------------------------------------------------------------------------

//<<<<<<<<<<<<<<<<<<<<<<DISPLAYING INFORMATION>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

//Buffer size

snd_pcm_hw_params_get_buffer_size(hwparams, (snd_pcm_uframes_t*)&val);

printf("\nThe buffer size is %d \n",val);

//Buffer time

snd_pcm_hw_params_get_buffer_time(hwparams, &val,0);

printf("\nBuffer time is : %d \n",val);

//Period size

snd_pcm_hw_params_get_period_size(hwparams,&frames,0);

printf("\nperiod size : %d \n",(int)frames);

//Periods between buffers

err=snd_pcm_mmap_begin(pcm_handle,&areas,&offset,&frames);

//Periods between buffer

snd_pcm_hw_params_get_periods(hwparams,&val,0);

printf("\n Periods between buffer is : %d \n",val);

//<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>.

if(err<0)

{

printf("\nMMAP error\n");

return -1;

}

else printf("\n%d\n",err);

commitres = snd_pcm_mmap_commit(pcm_handle,offset,frames);

if(commitres<0)

{

printf("\nFrames not committed to memory\n");

}

int dest = open("sample3.wav",O_RDONLY);

if(dest<0)

{

perror("\nFile could not be opened\n");

return -1;

}

//int *c = offset;

buffer = (unsigned char *)malloc(1000);

unsigned long buf = offset;

if(read(dest,&offset,1)<0)

{

perror("\nNo destination for read\n");

return -1;

}

struct timeval tvbefore,tvafter;

gettimeofday(&tvbefore,NULL);

while(read(dest,buffer,100)!=0);

gettimeofday(&tvafter,NULL);

printf("\nTime taken by read() is %09ld \n",tvafter.tv_usec-tvbefore.tv_usec);

/*

while(1)

{

if(read(dest,&offset,80)!=0)

{

//fread(buffer,sizeof(buffer),160,f1);

{

if(pcmreturn = snd_pcm_mmap_writei(pcm_handle,&offset,80)<0)

{

snd_pcm_prepare(pcm_handle);

printf("\n<<<<<<<Buffer Underrun>>>>>>>>\n");

break;

}

}

}

else break;

}

*/

}