为什么值得关注

它将二维码传输重新构想为连续高速光学通道，结合 RaptorQ 喷泉码、双通道二维码渲染和 WebAssembly 编解码器，实现可靠的纯浏览器气隙文件传输。

适合谁使用

需要在气隙或网络受限设备间传输文件的隐私敏感用户
研究二维码、喷泉码或 WebAssembly 的开发者
需要在无网络基础设施下完成离线设备到手机传输的团队
评估光学侧信道传输方法的安全研究人员

典型使用场景

在气隙或网络受限环境中将文件从屏幕传输到手机
在不向应用服务器上传文件的情况下传输文件
使用实验室 1 Mbps 配置测试高吞吐二维码流传输
在摄像头模糊、丢帧或二维码乱序时仍能恢复文件

项目优势

传输完全在浏览器中完成，文件不会上传到应用服务器
RaptorQ 交织让接收端可中途加入、丢弃模糊帧、接受乱序帧，并在收到足够唯一符号后重建数据
多层校验：逐帧 CRC、RaptorQ 对象 CRC、压缩载荷 CRC 和原始文件 CRC
测试工具使用真实 WebAssembly 渲染器和扫码器并加入曝光噪声，同时验证生产构建

使用前须知

高速双通道模式要求发送端全屏播放、接收端启用双通道模式，并让手机横向靠近且保持稳定
吞吐量受摄像头采集能力和二维码密度限制；1 Mbps 是实验室中摄像头损耗前的标称值
需要支持 WebAssembly 和摄像头访问的现代浏览器，不适用于所有设备

README 快速开始

QRFerry

QRFerry moves a file from one device to another as a live animated QR stream. The sender and receiver run entirely in the browser; the file is never uploaded to an application server.

Use it

Open the root page on the sending screen and choose a file.
Open /scan on the receiving phone and allow rear-camera access.
Start the QR stream and keep the complete code inside the phone's guide.
Save the file when RaptorQ recovery and the whole-file checksum reach 100%.

Robust through Turbo 30 use one stable QR target. Turbo 60 uses two V30-L lanes, updating them alternately at 30 fps each so one remains stable during every display transition. The opt-in 1 Mbps laboratory profile uses the same dual-lane design with V40-L for a nominal 1.40 Mbps optical payload channel before camera loss. Dual modes require fullscreen sender playback, the receiver's Dual lane option, and a landscape phone held close and steady.

Demo

This inline preview is generated from the final privacy-redacted demo. The full-resolution recording remains local at videos/qrferrydemo_timed_redacted.mov and is intentionally excluded from Git.

Protocol

Brotli quality 11 and gzip level 9 are both attempted; only the smallest representation is retained, and only when it saves optical bytes.
QR frames use raw byte mode, avoiding the Base45 expansion of the previous protocol.
Every frame carries a compact binary header, a RaptorQ symbol, and CRC-32.
File metadata is inside the protected RaptorQ object instead of repeating in descriptor beacons.
Source and repair symbols are interleaved. The receiver can join mid-cycle, discard blur, accept frames out of order, and reconstruct after receiving enough unique symbols.
Turbo 15 uses one V30-L code held for four refreshes on a 60 Hz screen. Turbo 30 holds one code for two refreshes. Turbo 60 alternates updates across two V30-L lanes, so each lane remains stable for two refreshes while their combined stream carries 60 symbols per second. The 1 Mbps laboratory profile applies the same scheme to two denser V40-L lanes.
Playback is synchronized to browser display refreshes. The sender reports its measured render rate; the receiver reports negotiated and delivered camera fps, completed scans per second, and decoder p50/p95 latency.
Dual scanning acquires at most two codes per exposure and

qr-data-transfer