7. Advanced7.5.6.7 Transport DelayWhat is Transport Delay ?The Transport Delay is the interval between the time at which an image frame is received from the first FPGA of the PMP and thetime at which the processing of this frame starts in the second FPGA of the PMP.frame B frame C frame Dframe B frame C frame Dzz = transport delay or TDRsignal comingfrom PMP (1st step)signal processingin PMP (2nd step)Image 7-77Transport delayDuring this delay all image information is stored in a memory block on the PMP.A Transport Delay set to the maximum value of 1023, corresponds with a delay of 16 ms.What can be done with the Transport Delay ?The data flow of any frame starts with pixel 1 of line 1 of this frame and is processed line by line.In the example of a top side bow distortion, the first pixel to be displayed is not pixel 1 of the original line 1, but pixel x (>1) of theoriginal line 1. This means that every pixel which comes before pixel x in the original line 1 must be stored in a temporary memory,before the processing of the frame can start.Image 7-78Transport Delay basic principleThe Transport delay can be adjusted manually or can be set to automatic.A short Transport delay creates a small delay with respect to the source, but a large delay is needed in case extremely distortedimages are needed (extremely curved screens).A delay set too short may introduce ’clipping’ phenomenons in the image.How to set Transport Delay to manual or automatic ?1. Start up the Geometry Edit menu2. Push the cursor key ↑ or ↓ to highlight Transport Delay... and press ENTER to select.R59770330 SIM 7QP SERIES 08/12/2014 93
