/// <summary>Initialize a VideoStream for an existing stream</summary>
        /// <param name="aviFile">The file that contains the stream</param>
        /// <param name="aviStream">An IAVISTREAM from [aviFile]</param>
        public VideoStream(int aviFile, IntPtr aviStream)
        {
            this.aviFile   = aviFile;
            this.aviStream = aviStream;
            Avi.AVISTREAMINFO streamInfo = GetStreamInfo(aviStream);

            //Avi.BITMAPINFOHEADER bih = new Avi.BITMAPINFOHEADER();
            //int size = Marshal.SizeOf(bih);
            Avi.BITMAPINFO bih  = new Avi.BITMAPINFO();
            int            size = Marshal.SizeOf(bih.bmiHeader);

            Avi.AVIStreamReadFormat(aviStream, 0, ref bih, ref size);

            if (bih.bmiHeader.biBitCount < 24)
            {
                size = Marshal.SizeOf(bih.bmiHeader) + Avi.PALETTE_SIZE;
                Avi.AVIStreamReadFormat(aviStream, 0, ref bih, ref size);
                CopyPalette(bih.bmiColors);
            }

            this.frameRate         = (float)streamInfo.dwRate / (float)streamInfo.dwScale;
            this.width             = (int)streamInfo.rcFrame.right;
            this.height            = (int)streamInfo.rcFrame.bottom;
            this.frameSize         = bih.bmiHeader.biSizeImage;
            this.countBitsPerPixel = bih.bmiHeader.biBitCount;
            this.firstFrame        = Avi.AVIStreamStart(aviStream.ToInt32());
            this.countFrames       = Avi.AVIStreamLength(aviStream.ToInt32());
        }