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Osprey-300 User’s Guide
If you enable cropping, key in some custom
settings, and then disable cropping, an
uncropped specification will be displayed and
your settings will disappear from view. However,
the driver does remember your custom settings,
and if you enable cropping again, they will
reappear.
An important note: The Osprey AVStream driver
only downscales video; it never up-scales it.
That is, the output video must be equal-sized or
smaller than the raw size of the incoming video.
If your crop specification would result in up-
scaling, the driver will ignore it and will capture
or display uncropped video.
For example, if your reference size is 720x480,
and the left, top, right, and bottom edges of your
cropping rectangle are 180, 120, 540, and 360,
so that the cropped size is 360x240, then your
video cannot be larger than the cropped size,
360x240.
Finally, recall that the cropped ROI is based on
a frame. Thus if a cropped ROI is setup defining
a 360x240 area, for example, then a capture of
video sized at 360x240 will result in video being
captured from two fields. If the source was
interlaced you may see interlacing artifacts in the
captured video. This may be initially confusing
since most users typically think of 360x240 video
capture only coming from a single field and thus
would not have interlaced artifacts.
However, in this case, the source video is only
360x240 in size (i.e. the cropped ROI) and thus
any captured video that is greater than the
field height within the cropped ROI (equal to
½ cropped ROI height) will result in a scaled
capture of multiple fields. Any capture less than
or equal to the field height within the cropped
ROI will result in a scaled capture of just a single
field within the ROI. Thus for this example, video
sizes greater than 120 in height to 240 in height
results in video from both fields being processed
by the scaler. In this example video sizes less
than or equal to 120 in height will result in video
being captured only from a single field.
Summary of Contents for Osprey-300
Page 1: ...Osprey 300 User s Guide...
