Creating binary fileformat

Below is an example of a C# console application that creates a single binary file containing all the audiobook files from a given directory, along with their metadata. This simple example demonstrates how to write the file names and contents into one binary file:

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556using System;
using System.IO;
using System.Text;
class AudiobookBinaryPacker
{
static void Main(string[] args)
{
// Replace with the path to your audiobooks directory
string audiobooksDirectory = @"path\to\audiobooks";
    // The output binary file containing all audiobook data
    string outputFile = @"path\to\output\audiobooks.bin";

    try
    {
        using (BinaryWriter writer = new BinaryWriter(File.Open(outputFile, FileMode.Create)))
        {
            PackDirectory(audiobooksDirectory, writer);
        }
        Console.WriteLine("Audiobooks have been successfully packed into the binary file.");
    }
    catch (Exception ex)
    {
        Console.Error.WriteLine($"An error occurred: {ex.Message}");
    }
}

static void PackDirectory(string directoryPath, BinaryWriter writer)
{
    foreach (string filePath in Directory.GetFiles(directoryPath))
    {
        PackFile(filePath, writer);
    }

    foreach (string subDir in Directory.GetDirectories(directoryPath))
    {
        PackDirectory(subDir, writer);
    }
}

static void PackFile(string filePath, BinaryWriter writer)
{
    FileInfo fileInfo = new FileInfo(filePath);
    byte[] fileNameBytes = Encoding.UTF8.GetBytes(fileInfo.Name);
    byte[] fileContentBytes = File.ReadAllBytes(filePath);

    // Write the length of the filename, the filename itself, the file size, and then the file content.
    writer.Write(fileNameBytes.Length);
    writer.Write(fileNameBytes);
    writer.Write(fileContentBytes.Length);
    writer.Write(fileContentBytes);

    Console.WriteLine($"Packed file: {fileInfo.Name}");
}

}

To use this code:

1. Replace path\to\audiobooks with the path to your audiobooks directory.
2. Replace path\to\output\audiobooks.bin with the desired output path for the binary file.

This program will create a binary file (audiobooks.bin) where each audiobook file is preceded by its filename length and content size (both as integers) followed by the actual filename (as bytes) and file content (as bytes).

This is just a starting point. Depending on your requirements, you might want to add more metadata, error checking, or features like compression or encryption.

Please note that this code does not include functionality to read from the created binary file. You would need to implement corresponding logic in your application that reads and interprets this binary format to extract individual audiobook files or play them directly from the binary file.