kig · HackerTrans

2개월 전discuss

For fun, here's a copy-paste-into-devtools version: (async()=>{const r=await fetch(`data:text/plain;base64,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`),d=r.body.pipeThrough(new DecompressionStream('gzip')),t=await new Response(d).text();eval(t);})();

kig

2개월 전discuss

Thanks for trying it, sounds like a bug I've been running into for a couple days where the wasm stream decoder does a bad memory access. I made some buffer lifetime fixes, next up a more complete stress test and fuzzing to see if I can pinpoint it.

kig

2개월 전discuss

Depends on the zoom. With this setup you can transfer about 0.1 B/s per pixel of 60 FPS video. So a 65" screen and 1080p camera at 10 meters away would max out at 2 kB/s with the normal lens (26mm equiv) or 45 kB/s with the tele lens (120mm equiv.)

I'm cooking something faster but depends on the job situation and funding whether I have time to spend on it.

Napkin math: QR codes encode 0.75 bits per module, each module needs about 3 pixels of camera resolution, and the temporal resolution is quite dodgy as well, maybe 0.25 * min(cameraHz, screenHz). So if everything is perfect, 44 kB/s at 60Hz per a 500x500 pixel patch. I've seen ~250 kB/s when a 1920x1080@60 transfer is working well. At 4k@30, you might reach 0.5 MB/s. If you throw in the 2x subsampled UV channels to transfer data as well, you might get an extra 50%.

kig

2개월 전discuss

The handshake details are passed alongside the data so that if a direct connection is successful, the network races the optical transfer.

kig

2개월 전discuss

This is cool and minimalistic!

I've been noodling on https://qr-send.com which is a slightly more polished version of the "erasure fountain codes + stream of QRs"-idea, inspired by divan's Txqr posts but using Wirehair FEC for the fountain code (basically: you receive ~file size bytes via QR codes and it magically assembles them into the source file regardless of missed codes).

It's an offline-first progressive web app and there are native & wasm builds for the sender. The browser-to-browser transfer falls up to WebRTC when possible because 30 MB/s over wifi beats a 100 kB/s QR stream. The QR scanner is a heavily-optimized WASM build of zbar, scanning at 60 fps on mobile & multiple QRs per frame (but it's finicky! Work in progress.)

kig

5개월 전discuss

If you want to mess with this at home, I've been vibe coding https://github.com/kig/formalanswer to plug theorem provers into an LLM call loop. It's pretty early dev but it does have a logic rap battle mode.

kig

6개월 전discuss

"We leverage APIs like CUDA streams to avoid blocking the GPU while the host processes requests.", so I'm guessing it would let the other GPU threads go about their lives while that one waits for the ACK from the CPU.

I once wrote a prototype async IO runtime for GLSL (https://github.com/kig/glslscript), it used a shared memory buffer and spinlocks. The GPU would write "hey do this" into the IO buffer, then go about doing other stuff until it needed the results, and spinlock to wait for the results to arrive from the CPU. I remember this being a total pain, as you need to be aware of how PCIe DMA works on some level: having your spinlock int written to doesn't mean that the rest of the memory write has finished.

kig

3년 전discuss

Around 37 trillion cells, of which 25 trillion are red blood cells. Plus a 100 trillion gut bacteria.

The brain is about 0.1 trillion cells, of which 0.02 trillion cells are the cerebral cortex, which is occasionally consulted by the rest of the brain on matters such as what words to enter into this textarea.

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