Reading ID3V2 Tags in C language

Hello everyone,

I am a beginner in programming and I have an assignment from my university to wright a code in C for reading mp3 files in ID3V2 format. I have searched the web and tried to put together some pieces and I came up with this code. Although that I have put many error warnings from top to bottom I can not still understand where is the mistake.

My first problem is that the code it compiles with only one warning:
warning: format ‘%s’ expects a matching ‘char *’ argument [-Wformat]

Unfortunately I do not know what is my mistake here. I am trying to print the input of the user in case of a mistake, thought by doing this I get this warning.

My second problem is when I am executing the code I get as an output:
The program has failed to get the Tags

Any help would much appreciated.

Thank you in advance for your time reading my problem.

Best Regards,
Thanos

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct{
   char tag[3];
   char title[30];
   char artist[30];
   char album[30];
   char year[4];
   char comment[30];
   unsigned char genre;
}mp3Info;

 int main (int argc, char *argv[])
   {
	   if ( argc != 1 )  /* Input from user argc should be 1 for correct
						  *	execution. The argument count variable
						  * stores the number of arguments plus one. */ 
		{
			 /*We print argv[0], if the program that user has chosen for
			  * execution it is not correct as input if has more inputs*/ 
			printf( "Please choose one file: %s  <silence.mp3> \n", argv[0] );
		}
		else 
		{
			FILE *file; /* A file pointer is a variable of type FILE, 
						 * we declare a file pointer.*/
						 
			file = fopen("silence.mp3", "rb");  /* Open the file
												 * silence.mp3 in
												 * "reading" mode "r". */
												 
			if (file == NULL) {
				/* If the file could not open for a variety of reasons
				 *  the program should inform us by print the document
				 *  and exit.*/ 
				printf("I couldn't open: %s for reading.\n");
				exit(0);
			}
			
			else 
			{
				mp3Info tag_in;

				/* Set the fseek to the beggining of the document with
				 * the help of the command SEEK_SET, condition if fail*/
				 
				if (fseek(file, 0 *sizeof(mp3Info), SEEK_SET) == -1)
				{
					fprintf(stderr, "Not able to fseek");
					return EXIT_FAILURE;
				}

				/* Read the first name "tag" */
 				if (fread(&tag_in, sizeof(mp3Info), 1, file) != 1)
				{
					printf("Could not read the tag\n");
					exit (0);
				}

				/* Compare memory areas for verification */
				
				if (memcmp(tag_in.tag, "TAG", 3) == 0)
				{
					/* Verify that names are where as we expect */
					printf("Title: %.30s\n", tag_in.title);
					printf("Artist: %.30s\n", tag_in.artist);
					printf("Album: %.30s\n", tag_in.album);
					printf("Year: %.4s\n", tag_in.year);

					if (tag_in.comment[28] == '\0')
						
					{
						printf("Comment: %.28s\n", tag_in.comment);
						printf("Track: %d\n", tag_in.comment[29]);
					}

					else
					{
						printf("Comment: %.30s\n", tag_in.comment);
					}
						printf("Genre: %d\n", tag_in.genre);
					}
			
				else
				{
					fprintf(stderr, "The program has failed to get the Tags\n");
					return EXIT_FAILURE;
				}

			fclose(file);
			return 0;

			}
		}
	}