adiungere

Latin: to join, to attach to.

A dashcam with two cameras does not write two files. It writes one file holding both, and every gallery shows the first camera and nothing else. The rear camera is in the file. Nothing offers to show it.

Reaching it today means a command line and an external tool. That route works, and it silently discards the vendor telemetry the camera recorded alongside the video: the camera identity, one satellite fix per second, and the motion records that say how hard the car was hit.

These recordings are used as evidence. adiungere finds them, plays either camera or both together, and exports each one without re-encoding it, keeping the telemetry that every other route throws away. Nothing is uploaded: the work happens on the device holding the recording.

Not built yet. This is the foundation, in the open, from the first commit.

What exists today is the plan, the decisions behind it, the register of everything still unknown, and the tests that refuse to let the project claim more than it can prove. What does not exist is the product.

What it will prove, and what it will not

The strongest true statement any tool of this kind can make is that a sequence of bytes matches a digest recorded earlier. That is worth having, and it is narrow. adiungere will show that an extract carries the same video samples as the recording it came from, that a file has not changed since it was first seen, and that it existed no later than a given moment.

It will never say a recording is authentic, or that what it shows happened. Nothing attests for the camera, and no tool can reach either question. Saying otherwise would be the one thing that makes such a tool worse than useless in the place it is meant to be used.

Follow along