Yep that was the problem, it all works now, thanks!
I'd also like to program the LEDs to turn black (or switch off) when the arduino doesn't...
I already used another HDMI splitter that I had, and it gave the same issue. So I think it might be the video grabber that is fake.
I bought this...
I just finished a setup for any HDMI source using this guide. Everything works, however I have a problem with resolutions:
Separate names with a comma.
The vision of the MediaPortal project is to create a free open source media centre application, which supports all advanced media centre functions, and is accessible to all Windows users. In reaching this goal we are working every day to make sure our
software is one of the best.
The team works very hard to make sure the community is running
the best HTPC-software. We give away MediaPortal for free but hosting and software is not for us. Care to support our work with a few bucks? We'd really