CS-Script

//css_nuget taglib
using System;
using System.IO;

string source = @"\\media-server\tv_shows\Get Smart\Season1";

void main()
{
    foreach (string file in Directory.GetFiles(source, "*.mp4"))
    {
        string episode_name = Path.GetFileNameWithoutExtension(file);

        var mp4 = TagLib.File.Create(file);
        mp4.Tag.Title = episode_name;
        mp4.Save();

        Console.WriteLine(episode_name);
    }
}

C:\Temp>cscs mp4_retag.cs

dynamic script = CSScript.LoadCode(
                           @"using System.Windows.Forms;
                             public class Script
                             {
                                 public void SayHello(string greeting)
                                 {
                                     MessageBox.Show(""Greeting: "" + greeting);
                                 }
                             }")
                             .CreateObject("*");
script.SayHello("Hello World!");
//-----------------
var product = CSScript.CreateFunc<int>(@"int Product(int a, int b)
                                         {
                                             return a * b;
                                         }");
int result = product(3, 4);
//-----------------
var SayHello = CSScript.LoadMethod(
                        @"using System.Windows.Forms;
                          public static void SayHello(string greeting)
                          {
                              MessageBoxSayHello(greeting);
                              ConsoleSayHello(greeting);
                          }
                          static void MessageBoxSayHello(string greeting)
                          {
                              MessageBox.Show(greeting);
                          }
                          static void ConsoleSayHello(string greeting)
                          {
                              Console.WriteLine(greeting);
                          }")
                         .GetStaticMethod("*.SayHello" , ""); 
SayHello("Hello again!");