User guide

Chapter 4: 2D FIR Filter MegaCore Function 4–3
Functional Description
January 2013 Altera Corporation Video and Image Processing Suite
User Guide
Error Recovery
The 2D FIR Filter MegaCore function resolution is not configurable at run time. This
MegaCore function does not read the control packets passed through it.
An error condition occurs if an
endofpacket signal is received too early or too late for
the compile time configured frame size. In either case, the 2D FIR Filter always creates
output video packets of the configured size. If an input video packet has a late
endofpacket signal, then the extra data is discarded. If an input video packet has an
early
endofpacket signal, then the video frame is padded with an undefined
combination of the last input pixels.
1 For more information about the stall behavior and error recovery, refer to “Stall
Behavior and Error Recovery” on page 1–3.
Latency
Table 4–2 lists the approximate latency from the video data input to the video data
output for typical usage modes of the of 2D FIR Filter 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.
Table 4–2. 2D FIR Filter Latency
Mode Latency
Filter size: N × N
(N–1) lines + O
(cycles)
(1)
Note to Table 4–2:
(1) O refers to a small number of clock cycles, and is not of zero value.