...The system requires no direct network path, pairing process, native application, or permission beyond camera access. Fountain coding makes the stream tolerant of missed, blurred, duplicated, and out-of-order frames without requesting retransmission. Each QR frame includes session and file metadata, allowing a receiver to join an active stream or reset when a new session begins. QR decoding runs through zxing-cpp compiled to WebAssembly and uses workers to process camera frames efficiently. Configurable settings control payload size, transmission speed, QR density, capture resolution, and worker count, while a final hash verifies the recovered file.