// You can speed up the conversion using the following technique:
// 1) Generate video parts in parallel threads;
// 2) Combine these parts into final video.
// Let us say you have 20 slides.
// Then you can run a thread to convert 1-10 slides and another one to convert 11-20 slides.
// Finally combine these parts into a single one using .JoinWMVFiles(part1, part2, output) 
// or .JoingAVIFiles(part1, part2, output) functions.

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Threading;
using BytescoutImageToVideo;

namespace MultiThreadProcessing
{
    class ThreadData
    {
        public string[] InputFiles;
        public string OutputFile;

        public ThreadData(string[] inputFiles, string outputFile)
        {
            InputFiles = inputFiles;
            OutputFile = outputFile;
        }
    }

    class Program
    {
        private static int _numBusy;
        private static ManualResetEvent _doneEvent;

        static void Main(string[] args)
        {
            _doneEvent = new ManualResetEvent(false);
            _numBusy = 2;

            // variable to store video file extension
            string sVideoFileExt;

            // are we using WMV or AVI video format for output
            bool isWMV = false;

            // if is WMV then use .wmv extension
            if (isWMV) 
            {
                sVideoFileExt = ".wmv";
            }
            else // else use AVI
            {
                sVideoFileExt = ".avi";
            }

            // Start two conversion threads
            Console.WriteLine("Start first thread...");
            ThreadData threadData1 = new ThreadData(new string[] { "slide1.jpg", "slide2.jpg", "slide3.jpg" }, "Part1" + sVideoFileExt);
            ThreadPool.QueueUserWorkItem(DoWork, threadData1);

            Console.WriteLine("Start second thread...");
            ThreadData threadData2 = new ThreadData(new string[] { "slide4.jpg", "slide5.jpg", "slide6.jpg" }, "Part2" + sVideoFileExt);
            ThreadPool.QueueUserWorkItem(DoWork, threadData2);

            // Wait for both threads finished
            _doneEvent.WaitOne();

            // Join generates parts
            Console.WriteLine("Join parts into the final video file...");
            ImageToVideo converter = new ImageToVideo();

            if (isWMV)
            {
                converter.JoinWMVFiles("Part1" + sVideoFileExt, "Part2" + sVideoFileExt, "Result" + sVideoFileExt);
            }
            else
            {
                converter.JoinAVIFiles("Part1" + sVideoFileExt, "Part2" + sVideoFileExt, "Result" + sVideoFileExt);
            }

            // Open the output video file in default media player
            Process.Start("Result" + sVideoFileExt);

            Console.WriteLine("Done. Press any key to continue...");
            Console.ReadKey();
        }

        static void DoWork(object data)
        {
            ThreadData threadData = (ThreadData) data;

            try
            {
                // Create BytescoutImageToVideoLib.ImageToVideo object instance
                ImageToVideo converter = new ImageToVideo();

                // Activate the component
                converter.RegistrationName = "demo";
                converter.RegistrationKey = "demo";

                // Add slides
                foreach (string file in threadData.InputFiles)
                {
                    Slide slide = converter.AddImageFromFileName(file);
                    slide.Duration = 3000; // 3000ms = 3s
                    slide.Effect = SlideEffectType.seEaseIn;
                }

                // Set output video size
                converter.OutputWidth = 640;
                converter.OutputHeight = 480;

                // Set output video file name
                converter.OutputVideoFileName = threadData.OutputFile;

                // Run the conversion
                converter.RunAndWait();

                // Release resources
                Marshal.ReleaseComObject(converter);

                Console.WriteLine("Thread finished.");
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }

            if (Interlocked.Decrement(ref _numBusy) == 0)
            {
                _doneEvent.Set();
            }
        }
    }
}