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Video2NAND – Abusing video codecs for great computational power
- pseudosavant 2mo agoCool that you can make a NAND gate like this, but I was more hoping for something that showed how to practically (ab)use a video encoder for "great computational power" to do something real. Not just how to make a NAND gate with one.
- tverbeure 2mo agoI was hoping for some variant of the FORCEDENTRY iPhone Messages exploit, which built an entire CPU with the PDF fax blitting operations.
- pseudosavant 2mo agoFair enough. Maybe not that far, but perhaps do a little one thing with these NAND gates they theorized? My issue may even be more with the HN title than the blog post, because the post never suggests anything like using a video codec for "great computational power".
- thenthenthen 2mo agoI tried looking it up but failed to find any technical write ups of how this was done, do you have any links maybe? Super interesting to read.
- deleted 2mo ago[deleted]
- arjvik 2mo agoSadly doesn't look turing complete (yet) :(
- mrheosuper 2mo agoif you can make a nand gate, you can make any other logic gate, thus turing complete
- phire 2mo agoI think you also need some form of intermediate storage to be Turing complete. Not that this example doesn't have intermediate storage... But I suspect you could create or discover a mechanism that is expressive enough to implement any chain of logic gates, but is incapable of expressing storage (can't even use the gates to implement a latch) I'm also a little dubious of granting the "Truing complete" label to something that can't conditionally terminate (at minimum) Maybe you can trick a video codec into looping forever without new key frames (in which case it can never terminate), but most likely this would need to be implemented unrolled, so always terminates after a fixed number of iterations.
- akoboldfrying 2mo agoIt looks like you can only make "wires" that go down or to the right, so there's no way to connect up NANDs to make a latch or flip-flop (which would require wires going back up or to the left).
- phire 2mo agoIf you were limited to just a single frame of itra blocks, then yes. This would be an example of logic without storage. Also quite limiting as wires could never cross. But I was kinda jumping ahead and assuming VP8 allows you to mix and match intra and inter prediction modes within a single frame (and that inter prediction will feed into intra prediction... that might be a flawed assumption...) Inter prediction should allow you to copy from any block on the previous frame, effetely creating unlimited length wires in any direction. This also makes the previous frame latched storage, without having to construct a latch from gates.
- Roselol 2mo ago[flagged]
- nomel 2mo agoLooks like VP8 has a max resolution of 16383x16383 pixels. Looks like minimum block size is 4x4 pixels, so 4096x4096 blocks, with maybe 7x7 blocks per gate, including some wiring, so maybe something like 500x500 logic gates? I don't think we'll be running Doom, but you could definitely make a little CPU, with programs!
- picture 2mo agoWhat is this math from? How do you suppose there to be less gates than pixels? Also, different implementations may unroll to different degrees, with some lower thruput hardware doing stuff sequentially by reusing the same logic
- zamadatix 2mo agoTo have more gates than pixels would require surmising a method different than the article, since it uses a decent number of blocks per gate.
- moralestapia 2mo agoFunny this is how people initially started re-shaping some computational problems to resemble graphic pipelines and get "great computational power"; back when it was called GP(General Purpose-)GPU computing.
- akoboldfrying 2mo agoI was wondering whether there's any way to make wires "cross", which would be needed to construct a non-planar circuit. But even if there isn't a way to do this directly, Gemini tells me that it's possible to construct a planar circuit (built out of XORs which are themselves built out of NANDs) that effectively "crosses" two wires!
- deleted 2mo ago[deleted]
- fch42 2mo agoMapping the abilities of (fixed-function) "stream transformers" to compute is old, much older than "GPU libraries" or render pipelines and all that. I remember the Commodore Amiga used the blitter's combine to decode/encode floppy data, but there are likely other examples predating that. In which sense is VP8 "different" there from another "fixed-function" processor?
- woflo 2mo ago[flagged]