train_utils.c

#include "stdlib.h"
#include "train_utils.h"

uint32_t swap(uint32_t x) {
    return ((x>>24)&0xff) |
           ((x>>8)&0xff00) |
           ((x<<8)&0xff0000) |
           ((x<<24)&0xff000000);
}

void swapInPlace(uint32_t* arr, int size){
	for(int i=0; i<size; i++){
		*(arr+i) = swap(*(arr+i));
	}
	return;
}

void readImgHeader(uint32_t* head, FILE* ptr){
	if(fread(head, 4, 4, ptr) != 4){
		printf("Error reading the Image header\n");
		fclose(ptr); exit(1);	
	}
	swapInPlace(head, 4);
	printf("-------------------------\n");
	printf("magic number: %d\n", head[0]);
	printf("number of images: %d\n", head[1]);
	printf("number of rows: %d\n", head[2]);
	printf("number of columns: %d\n", head[3]);
	printf("-------------------------\n"); 
	return;
}

void readLabelHeader(uint32_t* head, FILE* ptr){
	if(fread(head, 4, 2, ptr) != 2){
		printf("Error reading the Label header\n");
		fclose(ptr); exit(1);
	}
	swapInPlace(head, 2);
	printf("-------------------------\n");
	printf("magic number: %d\n", head[0]);
	printf("number of images: %d\n", head[1]);
	printf("-------------------------\n");
	return;
}

int readNextImage(uint8_t* img, int img_size, FILE* ptr){
	if(fread(img, 1, img_size, ptr) != img_size){
		if(feof(ptr))
			return 0;
		printf("Error reading images\n");
		return 0;
	}
	return 1;
}