Thanks, I tried to implement GetAverageTimePerFrame in your ShowVideoFormats function below. Get the same value for all formats: 3333333 Seems I must advance TIEDirectShow for each format. Dont see how to get there ??
  // fills video formats list box
  ListBox1.Clear;
  with ImageEnView1.IO.DShowParams do
    for i := 0 to VideoFormatsCount - 1 do
    begin
      with VideoFormats[i] do
        begin
          s := SysUtils.Format('%s %dx%d %.0f MB/s', [Format, BitmapWidth, BitmapHeight,    BitRate / 1048576]);   
          s := s + ' '+inttostr(10000000 div GetAverageTimePerFrame);
          ListBox1.Items.Add(s);
        end;
    end;