XOR encryption to file in C lang

encryption.c

#include <stdio.h>
#include <stdint.h>
int main()
{
    uint8_t  c=0;
    const char *in="safe-mp4-1.bin";
    const char *out="video.mp4";
    FILE *fin=fopen(in,"rb");
    FILE *fout=fopen(out,"wb");
    if(fin&&fout){
        fseek(fin,0,SEEK_END);
        int64_t file_size=ftell(fin);
        fseek(fin, 0L, SEEK_SET);
        for(int64_t i=0;i<file_size;i++){
            if(fread(&c, sizeof(uint8_t), 1, fin)!=1){
                break;
            }else{
                c=~c;
                fwrite(&c,sizeof(uint8_t), 1, fout);
            }
        }
        fseek(fout,0,SEEK_END);
        file_size=ftell(fout);
        fclose(fin);
        fclose(fout);
    }
    printf("ok");
    return 0;
}