Recent video codecs are very efficient denoisers, removing film grain from old movies, so they don't look like the originals when decoded (and disappointing some people).
There are ideas for solving this going on, like characterizing the film grain with a model with some parameters. Then, the model and its parameters, not the actual pixels with the noise, are transmitted and generated at the decoder. with a processing that will make them ressemble the originals (without being exactly the originals). That is somehow a kind of semantic communication, in which instead of the actual information, you transmit the meaningful information, not the pixels at bit resolution. I see it a bit like using vector graphics instead of pixels for images (SVG vs. PNG), to be able to generate images of arbitrary resolution from the meaningful info. This is a way of breaking Shanon capacity limits. ---------------------------------------------------------------------- Date: Fri, 3 May 2024 13:48:37 +1200 From: Ulrich Speidel <u.spei...@auckland.ac.nz> To: starlink@lists.bufferbloat.net Subject: Re: [Starlink] It’s the Latency, FCC Message-ID: <77d8f31e-860b-478e-8f93-30cb6e073...@auckland.ac.nz> Content-Type: text/plain; charset="utf-8"; Format="flowed" There's also the not-so-minor issue of video compression, which generally has the effect of removing largely imperceptible detail from your video frames so your high-res video will fit through the pipeline you've got to squeeze it through. But this is a bit of a snag in its own right, as I found out about two decades ago when I was still amazed at the fact that you could use the parsing algorithms underpinning universal data compression to get an estimate of how much information a digital object (say, a CCD image frame) contained. So I set about with two Japanese colleagues to look at the reference image sequences that pretty much everyone used to benchmark their video compressors against. One of the surprising finds was that the odd-numbered frames in the sequences had a distinctly different amount of information in them than the even-numbered ones, yet you couldn't tell from looking at the frames. We more or less came to the conclusion that the camera that had been used to record the world's most commonly used reference video sequences had added a small amount of random noise to every second image. - the effect (and estimated information content) dropped noticeably when we progressively dropped the least significant bits in the pixels. We published this: KAWAHARADA, K., OHZEKI, K., SPEIDEL, U. 'Information and Entropy Measurements on Video Sequences', 5th International Conference on Information, Communications and Signal Processing (ICICS2005), Bangkok, 6-9 December 2005, p.1150-1154, DOI 10.1109/ICICS.2005.1689234 Did the world take notice? Of course not. But it still amuses me no end that some people spent entire careers trying to optimise the compression of these image sequences - and all that because of an obscure hardware flaw that the cameras which their algorithms ended up on may not have even suffered from. Which brings me back to the question of how important bandwidth is. The answer is: probably more important in the future. We're currently relying mostly on CDNs for video delivery, but I can't fail but notice the progress that's being made by AI-based video generation. Four or five years ago, Gen-AI could barely compose a credible image. A couple of years ago, it could do video sequences of a few seconds. Now we're up to videos in the minutes. If that development is sustained, you'll be able to tell your personal electronic assistant / spy to dream up a personalised movie, say an operatic sci-fi Western with car chases on the Titanic floating in space, and it'll have it generated in no time starring the actors you like. ETA: Around 2030 maybe? But these things will be (a) data-heavy and (b) aren't well suited for CDN delivery because you may be the only one to every see a particular movie, so you'll either need to move the movie generation to the edge, or you need to build bigger pipes across the world. I'm not sure how feasible either option is.
_______________________________________________ Starlink mailing list Starlink@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/starlink
