bt829bkrf ETC-unknow, bt829bkrf Datasheet - Page 38

• Manufacturer Part Number: bt829bkrf
• Description: Video Streamii Decoders
• Manufacturer: ETC-unknow

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1.0 Functional Description
1.7 Video Scaling, Cropping, and Temporal Decimation
1.7.6 Image Cropping
where:
values locally, the READ operation can be eliminated.
use a single field as opposed to using both fields. Using a single field will ensure
there are no inter-field motion artifacts on the scaled output. When performing
single field scaling, the vertical scaling ratio will be twice as large as when scal-
ing with both fields. For example, CIF scaling from one field does not require any
vertical scaling, but when scaling from both fields, the scaling ratio is 50%. Also,
the non-interlaced bit should be reset when scaling from a single field (INT = 0 in
the VSCALE_HI register). Table 1-8 lists scaling ratios for various video formats,
and the register values required.
Cropping enables the user to output any subsection of the video image. The
ACTIVE flag can be programmed to start and stop at any position on the video
frame as shown in Figure 1-14. The start of the active area in the vertical direction
is referenced to VRESET (beginning of a new field). In the horizontal direction it
is referenced to HRESET (beginning of a new line). The dimensions of the active
video region are defined by HDELAY, HACTIVE, VDELAY, and VACTIVE. All
four registers are 10-bit values. The two MSBs of each register are contained in
the CROP register, while the lower 8 bits are in the respective HDELAY_LO,
HACTIVE_LO, VDELAY_LO, and VACTIVE_LO registers. The vertical and
horizontal delay values determine the position of the cropped image within a
frame while the horizontal and vertical active values set the pixel dimensions of
the cropped image as illustrated in Figure 1-14.
If your target machine has sufficient memory to statically store the scaling
On vertical scaling (when scaling below CIF resolution) it may be useful to
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= bitwise AND
= bitwise OR
= bit shift, MSB to LSB
D829BDSA
VideoStream II Decoders
Bt829B/827B