One pass from camera frame to readable signal.

Syzygy is a small C kernel that turns a video frame into Braille dots, edge glyphs and a 16-bin spectrum in a single loop, using only integer arithmetic. It gives the same bytes on a laptop, a phone and a microcontroller, so a stranger can check any result against one number.

header-only C11
no malloc, no floats, no libc
6.8 KB as WebAssembly
same bytes in C, wasm and JS

Run it in this tab

Everything below is computed on your device, with no server involved. The same pass runs twice on every frame: once as the C kernel compiled to WebAssembly, once as an independent JavaScript port. The panel at the bottom tells you whether the two agreed, byte for byte.

Input

Dot threshold: 128 Edge threshold (squared): 6000 Spectrum row: 1

A synthetic pattern of moving rings, 160×96 pixels, which becomes 80×24 cells.

Braille · 8 dots per cell

Edge glyphs · 3×3 Sobel

Tone · argmax density

Spectrum · 16-point integer FFT of one row

Two engines, one answer

Frames compared

Identical, every byte

C → wasm, per frame

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JS port, per frame

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What happens inside the pass

The frame is read once into a fixed buffer. One loop visits every 2×4-pixel cell and works out its brightness, its Braille dots, its edge direction and its density character, all from values kept in local variables. One row of cells also goes through a small Fourier transform. Each result is written once, and the buffer is handed back exactly as it was found.

Diagram of the fused pass: NV12 frame, ingest into the arena, one loop per cell computing luma, Braille, Sobel edge glyph and argmax tone, a 16-point FFT on one row, outputs written once, and a CRDT mesh downstream. — Each numbered box is a shard: one header in `include/` and one test in `tests/`. Read the stage-by-stage walkthrough.

What the numbers let you do

Check someone else's result.Integer-only maths means a frame gives the same bytes on every CPU and compiler. The 32×16 test frame hashes to 0x6dbdd1a8 in native C, in WebAssembly and in JavaScript, so one number is enough to tell whether two devices saw the same thing.

Run where there is no runtime.No allocator, no floating point, no standard library. The same headers compile for a desktop, a 6.8 KB WebAssembly module with zero imports, and in principle a microcontroller.

Keep up with a live camera.The timing above is measured on your device. The pass has to fit in the time between display refreshes to keep up with a live camera, and it runs without a server round trip.

Share state without a coordinator.Grids of cells merge with a join that ignores order and duplicates, so devices that trade updates over a lossy link end up with the same picture without a server deciding who is right.