The binary could not be started at all (missing, not executable, bad args).
ffmpeg started and exited with a non-zero status.
The configured timeout elapsed and the process was killed.
An AbortSignal fired and the process was killed.
The binary is not present.
The binary is present but cannot be executed.
ffprobe failed or produced unusable output.
The installed binary is too old for a requested feature.
A capability guard rejected the request.
Arguments or paths failed validation before anything was spawned.
Atomic output was requested for a target that cannot support it.
Stable, machine-readable failure classification.
These values are part of the public API. New codes may be added; existing ones are not renamed or repurposed.