Setting Driver Properties
70
ViewCast
deinterlacing filter is applied. This may be initially confusing since most users typically think of 320 x
240 video capture only coming from a single field and thus would not have interlaced artifacts.
However, in this case, the source video is only 320 x 240 in size (i.e. the crop rectangle) and thus any
captured video that is greater than the field height within the crop rectangle (equal to ½ cropped
ROI height) will result in a scaled capture of multiple fields. Also, the driver will use both fields
whenever they are needed to interrogatively scale the output with best possible accuracy.
Default Output Size
The standard DirectShow Properties dialog allows you to select the height and width of captured
video from a drop-down list (Figure 50). The drop-down list has a particular range of choices that
may or may not fit your needs. The drop-down list includes one default size that is provided by the
capture driver. The Default Output Size control allows you to set up what default size will be shown.
Figure 50. Default Output Size
If you enable
Auto Size
, your default video size will be automatically sized to your crop settings. The
three radio buttons, 1X, 1/2X, and 1/4X, determine whether the output size is scaled down from the
crop size.
Example 1
: If you are running standard 640 x 480 NTSC video, and the Enable Cropping check box is
not checked, your crop size is 640 x 480. With Auto Size checked, and the 1X Crop radio button
selected, your default size will be 640 x 480; with 1/2X, 320 x 240; and with 1/4X, 160 x 120.
Example 2
: If you have enabled cropping with size 320 x 240 (one quarter of the full video area), the
default Auto Sizes are as follows: 1X, 320 x 240; 1/2X, 160 x 120; 1/4X, 80 x 60.
If you leave Auto Size unchecked the default size radio buttons are disabled and the height and
width edit boxes are enabled. You can set any default size with the following two restrictions:
Since the driver does not upscale video, the default size must be smaller than the crop size. For
example, if the crop size is 320 x 240, you cannot set default output size 400x300.
Sizes are subject to the granularity requirements of the selected video format, as explained in the
Granularity section above. For example, if your video format is I420 and you try to set a default
width of 360, it will get adjusted down to 352 as soon as you click on another control.
Note: Pin Properties dialog default entry does not appear in the default VFW/DirectShow mapper
dialog. Thus, unless a VFW application, like Virtual Dub, specifically allows for custom
resolutions, the VFW app will only be able to select from the options the VFW/DirectShow mapper
lists.
Summary of Contents for Osprey PCI
Page 1: ......
Page 6: ......
Page 29: ...Osprey PCI User Guide ViewCast 23 Figure 15 VbiGraph utility...
Page 56: ...Setting Driver Properties 50 ViewCast Figure 35 Extras...
Page 67: ...Osprey PCI User Guide ViewCast 61 Figure 46 Weighting...
Page 70: ...Setting Driver Properties 64 ViewCast...
Page 77: ...Osprey PCI User Guide ViewCast 71...
Page 107: ...Osprey PCI User Guide ViewCast 101...
Page 114: ......
Page 118: ...Appendix C Troubleshooting 112 ViewCast...
Page 125: ......