2 Configuring Your Network Adapter for GigE Visionscape System Components – Add in the 2.59 milliseconds to actually send the data. 2.59 + 27.71 = 30.3 milliseconds per frame. – The camera could run at 33 fps. – Set the inter-packet delay in the registry in exactly the same way as you set the packet size. Note: The Visionscape GigE Camera Control Tool includes a tool to calculate the inter-packet delay. Feel free to use this only when you understand the material presented here! FrontRunner Live Video When you go into Live Video in FrontRunner with the zoom set to 1, a frame rate is displayed on the top left corner of the picture. For instance, it might say 30.1 fps.
This means that Visionscape is displaying images at 30.1 fps. It does not mean that the camera is running at this rate and, in fact, it means that the camera is running at least twice as fast as that. This is due to the way FrontRunner handles live video from the camera. Imagine that you are using a VGA camera that can output data at slightly more than 90 fps. The display on the PC can probably only manage 60 fps. FrontRunner works as follows: The camera is put into a continuous acquisition mode. If the inter-packet delay is negligible it will indeed be acquiring frames at 90 fps. FrontRunner will take a frame and then process it before displaying it on- screen.
This process is sequential and FrontRunner will not take another frame until it has finished with the image display. It is not “pipelining” the process the way it does when acquiring images at runtime with triggers. The sequential nature of the capture-draw-capture-draw process means that the best FrontRunner can ever do is 50% of the camera frame rate. This also depends on how fast the memory is, how fast the CPU itself is, and how fast the drawing operations are. It may in fact take more than the frame time to complete the drawing in which case FrontRunner will only show one in three frames.
Experiments on a Core2Duo workstation with a dedicated graphics card and an Intel Pro/1000 NIC connected to a camera showed that the maximum frame rate for live video in FrontRunner was 36.9 frames per Visionscape GigE Camera Guide 2-35