After some hours of trying to make a still photo slideshow with ffmpeg, I gave up. Some of the features are missing on the Windows version, would probably have been easier using Linux.
So I used the inbuilt video editor in Windows 10 to take a bunch of still photos, add music courtesy Steppenwolf. Then finally added my watermark of DonCharisma.org with ffmpeg.
So, long story short – it’s some photos I took, with music 🙂 Experimenting with a different format for presenting my photos – rather than a long page of photos.