I'm having trouble getting PowerPoint slides to display properly on a screen, but it's not the usual black edge problem I've seen in my Google searches. At least I don't think so.



I'm feeding the output of an HD video camera into a Roland V-1HD video switcher, via HDMI. I've also got a PowerPoint file open on an iPad Mini 4, and it's feeding into a second input on the switcher, also via HDMI. The PowerPoint file consists of slides designed to be "lower thirds," iow informational titles which will appear in the lower third of the screen.

The idea is to composite, or overlay, the lower third onto the video, so it will appear in the video. You've seen this sort of thing in news and sports shows. The switcher makes this relatively easy, except...

The process goes smoothly at first. I engage the composite effect, and the lower third appears in the video. But after a minute or two, black edges appear on all 4 sides of the composited video, obscuring the portions of the source video which lie beneath the black edges. The source video does not get smaller...it is the same size it was, but parts now lie behind the black edges.

This happens even if I don't touch anything. It also happens if I do make changes...for example repeatedly engaging and disengaging the effect. It will work fine for a few or several times, then the black edges appear.

If I turn the switcher off and then on again, everything is fine for a few minutes, then the black edges reappear.

I called Roland tech support, and the technician said it's a PowerPoint issue. I'm not sure of that, but it's worth a try. The switcher is very high quality and works well in all other regards.

I also tried feeding the PowerPoint into the switcher from my laptop, but then the black edges are ALWAYS present if I'm using the overlay effect. The laptop is set to its maximum screen resolution, which is 1600x900.

The video from the camera is 1920x1080. The PowerPoint slides are 16:9. I've also tried 16:10, and various custom sizes. Nothing cures the problem.

Pretty dang frustrating. Any thoughts? Thanks.