C# - DirectX.capture; - Frame captured Length too big

See more:

C#

DirectX

capture

frame

, +

Using Directx.Capture; to Capture a picture from a Webcam (Capture the Frame from the Preview PictureBox). Displaying Length of that Frame is sometimes (rare) ok : around 25000 Most of the time is more than 10x larger, around 320000! Why is that? width and height always the same in both cases though! (640x480)

 public Filter VideoInput = null;
 public Capture CaptureInfo = null;
 public Filters InputOptions = new Filters();


 private void startCap(int camNum = 0) {
      this.VideoInput = this.InputOptions.VideoInputDevices[camNum];
      this.CaptureInfo = new Capture(this.VideoInput, null);
      this.CaptureInfo.PreviewWindow = pictureBox1;
      this.CaptureInfo.RenderPreview();
      this.CaptureInfo.FrameCaptureComplete += new Capture.FrameCapHandler(CaptureInfo_FrameCaptureComplete);
      CaptureInfo.CaptureFrame();
}

 void CaptureInfo_FrameCaptureComplete(PictureBox Frame)
      {
           Image nwImage = Frame.Image;
           using (MemoryStream ms = new MemoryStream())
           {
               nwImage.Save(ms, ImageFormat.Png);
               Debug.WriteLine("length "+ms.Length);  //<===== length
               ms.Close();
               ms.Dispose();
           }
  }

Just saying, the ligter image with low length of 25000, is correct and displaying properly. And i would like to find where the problem comes from to keep the Frames ALWAYS around that size only. please help :)