OK. That's good to know about the webm container. So HLV then? I mean MPEG gave us DVDs and motion detection for surveillance cameras by only streaming the changes in the video frames... Why can't resolution be just another stream to peel out?
Discussion
From what I can find, H264 technically has your concept in the spec, but no actual widespread implementation of that. Basically no way to use what people have right now to show them different video qualities without separate transcodes. Kind of an odd baked in limitation