Barco R92112011, User Manual

Page: 97 / 210

7. Advanced
7.5.6.7 Transport Delay
What is Transport Delay ?
The Transport Delay is the interval between the time at which an image frame is received from the fi rst FPGA of the PMP and the
time at which the processing of this frame starts in the second FPGA of the PMP.
frame B frame C frame D
frame B frame C frame D
z
z = transport delay or TDR
signal coming
from PMP (1st step)
signal processing
in PMP (2nd step)
Image 7-77
Transport delay
During 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 fl ow 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 fi rst pixel to be displayed is not pixel 1 of the original line 1, but pixel x (>1) of the
original 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 7-78
Transport Delay basic principle
The 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 distorted
images 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 menu
2. Push the cursor key ↑ or ↓ to highlight Transport Delay... and press ENTER to select.
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