User guide

9–2 Chapter 9: Clipper MegaCore Function
Parameter Settings
Video and Image Processing Suite January 2013 Altera Corporation
User Guide
Error Recovery
On receiving an early endofpacket signal, the Clipper stalls its input but continues
writing data until it has sent an entire frame. If it does not receive an
endofpacket
signal at the end of a frame, the Clipper discards data until the end-of-packet is found.
1 For more information about the stall behavior and error recovery, refer to “Stall
Behavior and Error Recovery” on page 1–3.
Latency
Table 9–2 lists the approximate latency from the video data input to the video data
output for typical usage modes of the Clipper MegaCore function. You can use this
table to predict the approximate latency between the input and the output of your
video processing pipeline.
The latency is described using one or more of the following measures:
■ the number of progressive frames
■ the number of interlaced fields
■ the number of lines when less than a field of latency
■ a small number of cycles O (cycles)
The latency is measured with the assumption that the MegaCore function is not being
stalled by other functions on the data path (the output ready signal is high).
1 The latency associated with the initial buffering phase, when a MegaCore function
first receives video data, is not included.
Parameter Settings
Table 9–3 lists the Clipper MegaCore function parameters.
Table 9–2. Clipper Latency
Mode Latency
All modes O (cycles)
(1)
Note to Table 9–2:
(1) O refers to a small number of clock cycles, and is not of zero value.
Table 9–3. Clipper Parameter Settings (Part 1 of 2)
Parameter Value Description
Maximum width
32 to input image width,
Default = 1024
Specify the maximum width of the clipping rectangle for the input field
(progressive or interlaced).
Maximum height
32 to input image height,
Default = 768
Specify the maximum height of the clipping rectangle for the input field
(progressive or interlaced).
Bits per pixel per
color plane
4–20, Default = 8 Choose the number of bits per pixel (per color plane).
Number of color
planes in sequence
1–3
Choose the number of color planes that are sent in sequence over one
data connection. For example, a value of 3 for R'G'B' R'G'B' R'G'B'.