Comment by peterburkimsher | Hacker News Reader

Comment by peterburkimsher | Hacker News Reader

peterburkimsher

I'm interested in learning more about VGA and HDMI, because I'd like to build a hardware freeze button.

On an old church projector, there was a button on the remote so I could freeze the screen. Then I could switch from PowerPoint to QuickTime Player (or whatever else) without disturbing everybody who was watching. Newer equipment (some projectors, most TVs) lack this feature. I'd like to build a box that stores the current frame in RAM, and has a simple toggle switch between the stored frame or the live video feed.

After a recommendation for the NeTV, I asked bunnie, and he said that the NeTV2 is a good choice for HDMI. It's pretty expensive though, and doesn't support HDCP.

https://github.com/AlphamaxMedia/netv2-ideas/issues/21

If anybody else has some guidance about how to proceed with this project, or some mutual interest that could translate into nagging me to actually do it, please get in touch!

This is actually a rather involved thing that you want to do here. Short answer is that you really need a presentation switcher or something similar that uses FPGA. If you want to roll your own, you can do it, but it's probably not gonna be worth the time investment.

NETV2 (Libre mode) is probably the best bet for hardware that will both do the job and has at least some example stuff that will be similar. It's FPGA based, but it will require a lot of effort to implement.

Other than that you are looking at the HDMI or DVI TxRx cards along with an FPGA dev board. Terasic's Altera boards and expansion cards, for instance will do the job and they offer VGA, DVI and HDMI interfaces for a large number of their dev boards. Anything along this vein will cost a lot more than NeTV2

IMO If you want to rely on something for a large commercial public presentation, I really wouldn't hack something together. Just buy a presentation switcher.

If an off the shelf solution is okay, look into live veejay/VJ software and hardware, or maybe game streaming/screencasting or other live broadcast tools. You can add VGA and HDMI capture cards to a computer, then use software to pause or switch inputs.

Yes, I bought an Elgato Cam Link 4K recently, and I could do it with CamTwist. I'd rather reduce the lag though, and the physical size/complexity of an extra computer.

I wonder if you could do this with an HDFury Vertex or Integral. All the hardware is there (including dealing with HDCP), but I don't think they have devkits available that would let you add features to the firmware.

$8 VGA2HDMI converter box from ebay will make NeTV2 work with analog source, $10-20 hdmi splitter will strip HDCP

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