Is it common to call these sprites in British English? I would call them "thumbnails".

Back in the day a sprite was a smaller 2d bitmap you'd superimpose on the screen. A key frame was a marker like this.

A long time ago, we used this approach to play videos at 15 fps in IE6, with no flash or realplayer plugins required! No sound though...

I've used vcs[0] to make contact sheets from videos. It has a nice feature that if it detects the frame is blacked out, it will shift the capture time so every frame on the sheet has something to look at. Easy syntax to set capture at every delta or capture x number of frames evenly distanced, columns per row, ignore a set length of end time, and frame size.

[0] https://p.outlyer.net/vcs

A "sprite" is commonly understood to have no background, so I'd say these are closer to thumbnails.

I wish there was some way to get vlc to use external sprite files.

While I'm thinking about it, external chapter files would be great too. Then you could make your own bookmarks without modifying the video file.

I get chills every time I watch this open source video. I don't know who created these mongrel creatures, but it's worse than a horror flick.

interesting will probably integrate as sprite mode in my ffmpeg video editor https://newbeelearn.com/tools/videoeditor/

Cool thanks