/* compress_wav.c

* 2015 Dec 7 Yinpeng Chen, Acadia University

* MSc student in Computer Science: for eeg data compression

*/

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <unistd.h>

#include <math.h>

#include "operator_wav.h"

#define PI 3.14159265

int main()

{

int i = 0;

int main_choice;

struct sin_coeff sin_coe1;

struct sin_coeff sin_coe2;

struct sin_coeff sin_coe3;

struct sin_coeff sin_coe4;

char * infile_name;

FILE * fp;

char * buffer = malloc(sizeof(char)* 1024 * 2 * 8);

printf("***Welcome to eeg data testing system!!!***\n");

printf("1. read a wav file.\n") ;

printf("2. check the data of loaded wav file.\n");

printf("3. set a sin wav.\n");

printf("4. write the new file\n");

printf("******************************************\n");

scanf("%d", &main_choice);

safe_flush(stdin);

printf("your choice: %d!\n", main_choice);

printf("\n");

if (main_choice == 1) {

infile_name = "4cmotion.wav";

if(( fp = fopen(infile_name, "rb")) == NULL){

fprintf(stderr, "ERROR: cannot open file: %s!\n", infile_name);

return 1;

}

if( fread(buffer, 1, 44, fp) != 44 ||

memcmp(buffer, "RIFF", 4) ||

memcmp(buffer + 8, "WAVEfmt ", 8) ||

memcmp(buffer + 36, "data", 4)

){

fprintf(stderr, "This file is not wav file file! Check the header\n");

fclose(fp);

return 1;

}

// unsigned bps = 16;

//read chunk size

/*

unsigned * pos = (unsigned *) malloc (4);

fseek(fp, 4, SEEK_SET);

fread(pos, 1, 4, fp);

unsigned chunksize = array2data(pos, 4);

printf("chunksize is %u\n",chunksize);

fflush(stdout);

fflush(stdin);

safe_flush(stdout);

safe_flush(stdin);

*/

//read channel number

unsigned * pos =(unsigned *) malloc(4);

fseek(fp, 22, SEEK_SET);

fread(pos, 2, 1, fp);

unsigned channel = array2data(pos,2);

printf("channel number: %u\n", channel);

//read sample rate number

fseek(fp, 24, SEEK_SET);

fread(pos, 4, 1, fp);

unsigned sample_rate = array2data( pos, 4);

printf("sample rate is %u\n", sample_rate);

//read total samples

fseek(fp, 40, SEEK_SET);

fread(pos, 1, 4, fp);

unsigned total_samples = array2data(pos, 4) / 2;

printf("total samples is %u\n", total_samples);

free(pos);

//sleep(1);

//data store section

short * data_store = (short *)malloc(total_samples * 4);

fseek(fp, 44, SEEK_SET);

if ( fread(data_store, 2, total_samples, fp) == 0)

{

printf("I can't read any data from wav file!\n");

}

fclose(fp);

fflush(fp);

/* for( i = 0; i < total_samples; i++)

{

printf("The data_store[%u] is %hd\n", i, data_store[i]);

}*/

unsigned sub_samples = total_samples / 4;

short * channel1_data = (short *)malloc(total_samples);

short * channel2_data = (short *)malloc(total_samples);

short * channel3_data = (short *)malloc(total_samples);

short * channel4_data = (short *)malloc(total_samples);

short * channel_bakup = (short *)malloc(total_samples*2);

for( i = 0; i < total_samples; i++)

{

if(i < sub_samples)

{

channel1_data[i] = data_store[i*4];

channel2_data[i] = data_store[i*4+1];

channel3_data[i] = data_store[i*4+2];

channel4_data[i] = data_store[i*4+3];

}

channel_bakup[i] = data_store[i];

}

//write and generate full(contains 4 channels) wav file

char * outfile_full = "4cfull.wav";

write_wav(outfile_full, sub_samples, channel_bakup, sample_rate, channel);

//find max and min value in subchannels

unsigned channel1_diff = array_diff( channel1_data, sub_samples);

unsigned channel2_diff = array_diff( channel2_data, sub_samples);

unsigned channel3_diff = array_diff( channel3_data, sub_samples);

unsigned channel4_diff = array_diff( channel4_data, sub_samples) ;

printf("The channel1_diff is %u, channel2 %u, channel3 %u, channel4 %u\n", channel1_diff,channel2_diff, channel3_diff, channel4_diff);

//sleep(3);

//generate sine wave

//short * sine_data = (short *) malloc (total_samples);

sin_coe1 = find_best_coeff(channel1_data, channel1_diff, sub_samples, sample_rate);

sin_coe2 = find_best_coeff(channel2_data, channel2_diff, sub_samples, sample_rate);

sin_coe3 = find_best_coeff(channel3_data, channel3_diff, sub_samples, sample_rate);

sin_coe4 = find_best_coeff(channel4_data, channel4_diff, sub_samples, sample_rate);

printf("LOOK at main values:\n");

printf("minA1 is %d, minO1 is %d\n", sin_coe1.A, sin_coe1.omega);

printf("minA2 is %d, minO2 is %d\n", sin_coe2.A, sin_coe2.omega);

printf("minA3 is %d, minO3 is %d\n", sin_coe3.A, sin_coe3.omega);

printf("minA4 is %d, minO4 is %d\n", sin_coe4.A, sin_coe4.omega);

//short * sine_wave = (short *) malloc (total_samples);

short * final_data = (short *) malloc (total_samples);

int mark = 0;

for ( i = 0; i < sub_samples; i++)

{

mark = i;

final_data[mark] = channel1_data[i] - (0.05 * sin_coe1.A * channel1_diff) * sin( 2 * PI * sample_rate * i * sin_coe1.omega);

final_data[mark+1] = channel2_data[i] - (0.05 * sin_coe2.A * channel2_diff) * sin( 2 * PI * sample_rate * i * sin_coe2.omega);

final_data[mark+2] = channel3_data[i] - (0.05 * sin_coe3.A * channel3_diff) * sin( 2 * PI * sample_rate * i * sin_coe3.omega);

final_data[mark+3] = channel4_data[i] - (0.05 * sin_coe4.A * channel4_diff) * sin( 2 * PI * sample_rate * i * sin_coe4.omega);

}

printf("mark is %d",mark);

char * newfile = "4cnew.wav";

write_wav(newfile, sub_samples, final_data, sample_rate, channel);

/*

for(i = 0; i < sub_samples; i++)

{

error_data[i] = channel1_data[i] - sine_data[i];

printf("error data[%u] is %hu\n", i, error_data[i]);

}

*/

//int error_diff = array_diff( error_data, sub_samples);

//printf("error diff is %u, channel1_diff is %u\n", error_diff, channel1_diff);

}

return 1;

}