[mistercow]

I know it may be a little tangential to the original point, but I reckon you could cut this down considerably if you had more accurate psychophysical models than we do. Humans are probably not actually processing anywhere near 1.25 mbps of input, and as far as our actual experience, we're discarding the vast majority of the information we even take in.

Consider, for example, that if you could perfectly predict the exact path of a person's fovea as they watched an SD movie, you could aggressively compress everything more than a dozen pixels away from that. A few pixels further, and you wouldn't even need to store chroma information at all. Let's say you can do that at 100 kbps, and the pixels on the fovea are 1 mbps. That would put your total bitrate at about 105kbps for video. If you don't optimize audio at all, that brings the cost down to about $170B/year.

And that's not even with new psychophysics; it's just better input. Sure, playing it back would be hard, but in principle, you could fool a brain into thinking it was experiencing the data firsthand. I think it's reasonable to think this is still a massive upper bound. It's not unreasonable to think that a lifetime of human sensory experience could be encoded on the order of hundreds of gigabytes, if not less.

[gknoy]

If I were recording my life, I would not want to discard that, however -- I don't want to record merely what I actually saw/noticed, but rather what I would have seen or noticed if I had been looking elsewhere in my field of view.