Decimen · optical transfer
Move a file between two screens using nothing but light.
The transmitter shreds your file into LT-fountain droplets and paints them as an animated QR stream. The receiver watches the pixels, feeds every readable frame into the same WebAssembly codec, and rebuilds the file once enough droplets land — in any order, with no retransmission and no back-channel.
Self-describing frames
Each QR carries an 18-byte header: file id, total length, block size and the droplet seed. Point a camera at the stream mid-flight and it still decodes.
Loss is time, not failure
Droplets are XOR combinations chosen by a seeded PRNG shared by both ends. Any sufficiently large subset reconstructs the file; dropped frames only cost seconds.
Two screens, for real
Switch the receiver to Camera and point this phone at another device running the transmitter — the same decode path handles live optics.