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Are you saying that when Netflix streams a 480p version of a 4k movie to my TV they do not perform downsampling?



Yes. Down sampling makes only sense if you store per pixel data, which is obviously a dumb idea. You get a stream for 480p which contains frames which were compressed from the source files, or the 4k version. At some point there might have been down sampling involved, but you never actually get any of that data, you get the compressed version of those.


Not sure if I’m being dumb, or if it’s you not explaining it clearly: if Neflix produced low resolution frames from high resolution (4k to 480p), and if these 480p frames are what my TV is receiving - are you saying it’s not downsampling, and my TV would not benefit from this new upsampling method?


Your TV never receives per pixel data. Why would you use a NN to enhance the data which your TV has constructed instead of enhancing the data it actually receives?


OK, I admit I don’t know much about video compression. So what does my TV receives from Netflix if it’s not pixels? And when my TV does “upsampling” (according to the marketing) what does it do exactly?


It receives information about the spacial frequency content of the image. If you're unfamiliar, it's definitely worth looking into the specifics of how this works, as it's quite impressive! Here's a few relevant Wikipedia articles, and a Computerphile video:

https://en.wikipedia.org/wiki/JPEG#JPEG_codec_example

https://en.wikipedia.org/wiki/Discrete_cosine_transform

https://www.youtube.com/watch?v=Q2aEzeMDHMA




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