[_flux]

I didn't read the spec, but I assume that if a single-picture format doesn't have the concept of making use of reference pictures (so previous or future frames), it's leaving _a lot_ of compression potential on the table.

You can of course just have a sequence of individually compressed frames, just as you can do with PNG, TARGA, or JPEG, but these are not usually the ways you would want to distribute the video due to the huge sizes.