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Chapter 5: Analog Video Driver Properties
If you select “Both”, the horizontal granularity is
at least 2, because the Preview YUY2 format has
horizontal granularity 2. You would notice this
only if you select RGB32.
Enable Cropping
If you uncheck the Enable Cropping checkbox,
your video will not be cropped regardless of any
crop settings you might previously have made.
The edit boxes showing the edges, height, and
width of your crop will be read-only and will show
settings for full-frame, uncropped video.
If you check the Enable Cropping checkbox,
your video will be cropped to the indicated
boundaries. Previously stored crop settings will
be recovered.
Note that the crop width and height are subject
to the granularity requirements of the selected
video format, as explained in the previous
section. For example, if your video format is
I420 and you try to set a crop width of 360, it will
get adjusted down to 352.
It will be useful to understand when cropping is
performed in the hardware. Figure 14 shows an
overview of typical video processing.
The input to cropping is considered a full
resolution frame. Thus, although one may
think of video as being composed of fields, the
cropping parameters assume operation on a full
resolution interlaced frame (composed of two
fields) or a full resolution progressive frame.
Cropping then sets up a region of interest (ROI)
for further scaling and processing.
Once cropped, all other video operations are
processed on the cropped resolution. If you
check Enable Cropping, the six edit-boxes are
enabled. The Top and Left boxes are always
used to set the top left corner of the ROI. The
Right and Bottom boxes can be used to set the
bottom right corner of the ROI. The Right and
Bottom boxes implicitly set the width and height
of the ROI and modifications to these values
are reflected in the Width and Height boxes.
Optionally, you may set the Width and Height
boxes, which is often more natural anyway, and
let the driver implicitly change the Right and
Bottom values.
Typical Video Processing
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Summary of Contents for Osprey-300
Page 1: ...Osprey 300 User s Guide...
