Read information from song

MetaDataSong.cpp

/*
*reference from :
*http://supportforums.blackberry.com/t5/Cascades-Development/Reading-mp3-tags/td-p/2126579
*/
#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;
} mp3Tag;

QString ClassName::ReadInfoSong(const QString MP3_FILENAME) {
	FILE *fp = fopen(MP3_FILENAME, "rb");
	if (!fp) {
		perror("File open failed");
		return "1";
	}

	mp3Tag tag;
	// Seek to 128 bytes before the end of the file
	if (fseek(fp, -1 * sizeof(mp3Tag), SEEK_END) == -1) {
		perror("fseek failed");
		return "2";
	}

	// Read the tag
	if (fread(&tag, sizeof(mp3Tag), 1, fp) != 1) {
		fprintf(stderr, "Failed reading tag\n");
		return "3";
	}

		// Make sure we've got what we expect.
	if (memcmp(tag.tag, "TAG", 3) == 0) {
		// Found the tag where we expected
		printf("Title: %.30s\n", tag.title);
		printf("Artist: %.30s\n", tag.artist);
		printf("Album: %.30s\n", tag.album);
		printf("Year: %.4s\n", tag.year);

		if (tag.comment[28] == '\0') {
			printf("Comment: %.28s\n", tag.comment);
			printf("Track: %d\n", tag.comment[29]);
		} else {
			printf("Comment: %.30s\n", tag.comment);
		}
		printf("Genre: %d\n", tag.genre);
	} else {
		fprintf(stderr, "Failed to find TAG\n");
		return "4";
	}
	return tag.title+"-"+tag.artist+"-"+tag.album+"-"+tag.year;
}

/*
* Note MP3_FILENAME is a file path from song.
*/