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Video Scaler v4.0 User Guide www.xilinx.com 19
UG805 March 1, 2011
Chapter 2
Overview
Video scaling is the process of converting an input color image of dimensions X
in
pixels by
Y
in
lines to an output color image of dimensions X
out
pixels by Y
out
lines.
Within predefined limits, the Xilinx Video Scaler supports the modification of the X
in
, Y
in
,
X
out
, Y
out
input parameters during run-time on a frame basis. Furthermore, you may also
dynamically crop selected subject area from the input image prior to scaling that area. This
dynamic combination lends itself well to applications that require shrink and zoom
functionality.
The Xilinx Video Scaler supports real-time video inputs and memory interface inputs (that
is, a frame buffer). When connected to a real-time input source, the input clock and
horizontal and vertical (H/V) timing signals come directly from the input video stream. In
the case of a memory interface, standard memory handshaking signals may be used in
place of the H/V timing signals.
While maintaining image quality is usually of primary interest, it is subjective and heavily
dependent upon the end application. Moreover, image quality comes at a price in terms of
FPGA resources. Hence, while the core structure and architecture of the scaler is
maintained for all applications, flexibility is made paramount to enable users from all
applications to use this IP.