SDI2USB 3.0 User Guide
DirectShow video adjustm ents
It em
Descript ion
video, the Epiphan drivers will scale the im age for you (unless you
uncheck Scale im age t o m at ch st ream resolut ion, in which case the
im age will be cropped to m atch your chosen resolution).
Default im age
Select an im age to display when there is no signal captured from your
video grabber. The uncom pressed BMP im age m ust be located on
your video capture workstation.
Scale im age to m atch stream
resolution
If you are using a fixed resolution and choose not to scale the im age,
the captured im age will appear cropped to your specified resolution
when capturing with a DirectShow com patible utility. Generally the
cropping happens at the top left corner of the video, but test first to be
sure you see the sam e results.
Norm ally, when choosing to use a fixed resolution with DirectShow,
you'll want the Epiphan drivers to scale the im age for you. Use the
slider to determ ine the type of scaling you'd like. Scaling perform ance
is a tradeoff between quality and CPU cycles on the capture com puter.
Lower quality (left side of the slider) is faster and takes fewer CPU
cycles, where higher quality (right side of the slider) is slower and takes
m ore CPU tim e. Try different values out to find the one that works for
your specific use case.
Flip im age vertically
Use this check box to flip your captured im age vertically when sending
over DirectShow.
Lim it fram e rate to
Use this to lim it (or fix) the fram e rate for the data you send to
DirectShow.
For exam ple, if you're using a DirectShow-com patible application like
WebEx and you're sharing som ething relatively static (like a
PowerPoint presentation), you could lim it the fram e rate to 5 fps,
which would be plenty for people watching at the other end, and
would avoid filling your data pipe with identical im ages.
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