MP3 reader Learn programming with C# Sharp exercises

Lesson:

File Management

Exercise:

MP3 reader 100

Objetive:

ID3 specifications apply to any file or audiovisual container. However, it is usually applied primarily audio containers. There are three versions of the specification that are compatible. For example, a file may contain labels simultaneously version 1.1 and version 2.0. In this case, the media player must decide which are relevant.

ID3 version 1
This first specification is very simple. It consists of attaching a fixed block size of 128 bytes at the end of the file in question. This block contains the following tags: A header that identifies the presence of block ID3 and version. Specifically, said header comprises TAG characters.

Title: 30 characters.
Artist: 30 characters.
Album: 30 characters.
Year: 4 characters.
Comment: 30 characters.
Genre (music): a character.

All tags using ASCII characters except gender, an integer stored within a single byte. The musical genre associated with each byte is predefined in the standard definitions and includes 80 genera, numbered 0 to 79. Some breeding programs have expanded their own defined genres (from 80th).

Code:

using System;
using System.IO;
public class MP3Reader
{
    public static void Main()
    {
        const int SIZE = 128;

        byte[] data;

        Console.Write("Enter name: ");
        string name = Console.ReadLine();

        if (!File.Exists(name))
        {
            Console.WriteLine("Not exists");
            return;
        }

        try
        {
            FileStream file = File.OpenRead(name);
            data = new byte[SIZE];

            file.Seek(-128, SeekOrigin.End);
            file.Read(data, 0, SIZE);

            file.Close();

            byte b1 = data[0];
            byte b2 = data[1];
            byte b3 = data[2];

            if (Convert.ToChar(b1) != 'T' || Convert.ToChar(b2) != 'A' ||
            Convert.ToChar(b3) != 'G')
            {
                Console.WriteLine("not mp3 valid");
                return;
            }

            int i = 3;

            string title = "";
            for (; i < 33; i++)
            {
                if (data[i] != 0)
                    title += Convert.ToChar(data[i]);
            }

            string author = "";
            for (i = 33; i < 63; i++)
            {
                if (data[i] != 0)
                    author += Convert.ToChar(data[i]);
            }

            string album = "";
            for (i = 63; i < 93; i++)
            {
                if (data[i] != 0)
                    album += Convert.ToChar(data[i]);
            }

            string year = "";
            for (i = 93; i < 97; i++)
            {
                if (data[i] != 0)
                    year += Convert.ToChar(data[i]);
            }

            string comments = "";
            for (i = 97; i < 127; i++)
            {
                if (data[i] != 0)
                    comments += Convert.ToChar(data[i]);
            }

            Console.WriteLine("Data of MP3:");
            Console.WriteLine("----------------------------");
            Console.WriteLine();

            Console.WriteLine("Title: " + title);
            Console.WriteLine("Author: " + author);
            Console.WriteLine("Album: " + album);
            Console.WriteLine("Year: " + year);
            Console.WriteLine("Comments: " + comments);
            Console.WriteLine("Genre: " + data[127]);
        }
        catch (Exception)
        {
            Console.WriteLine("Error");
        }
    }
}