[peterburkimsher]

Looks great! Is there an FPGA board with HDMI in and out? I’d like to build an HDMI freeze button to transmit a single frame at the push of a button. (e.g. during a meeting or church when noticing mistakes on the PPT slides).

[mschuster91]

If you want something that's made for professional use, look at the BlackMagic ATEM series. I think that should have you covered.

[peterburkimsher]

Thanks, but I’d prefer open-source rather than professional.

[nsteel]

Have you conaidered a £10 HDMI capture card? Not open source, or much of a project, but it would Just Work.

[peterburkimsher]

I've got an Elgato Camlink, but need the freeze button (e.g. CamLink input to a Raspberry Pi full-screen, feeding through to HDMI output, with a GPIO button to pause the live stream).