ViewCast Osprey-450e - Manual (Page 32)

Setting Driver Properties
26 ViewCast
Source Width
Figure 22. Source Width
The Source Width control (Figure 22) can be used to trim the black left and right edges of an image.
This control is only available for NTSC video, and only when the Horizontal Format is set to Square
Pixels such that the reference size is 640 x 480.
To trim an image:
1. With video preview running, click 720 to display the entire image, which usually includes
black left and right edges. Changes appear interactively.
2. Use the Horizontal Delay control immediately above this control to center them image so
the black edges are of equal width.
3. Click 704 to trim the image to the nominal borderless width.
4. Click + and - to adjust the trimmed size so that the black edges are completely removed but
no active video is lost. The allowed range is 688 to 720.
It is possible to obtain the same result using the cropping control (Size and Crop Tab) but there are
some differences.

The Source Width control affects all pins and all filters on the device, whereas the crop
control must be set separately for all SimulStream filters.

In Post-Processing Mode, this operation is often more efficient in terms of processing than a
crop operation. The crop and scale are done in hardware, so if you are using the resultant
640 x 480 image directly without further cropping there is no scale/crop processing cost
incurred.