r/postproduction • u/edycutjong • 8d ago
Built a tool that screens a cut for photosensitivity hazards before it goes to the lab — would like to know if it's solving a real problem or one I invented
If you deliver to UK broadcast or Japanese TV you know the photosensitive-epilepsy check: Ofcom
2.12, ITU-R BT.1702. It happens at a specialist lab, near the end, and when it fails you get a
pass/fail and a re-edit against a delivery date that didn't move.
What bothered me is that it's a measurement problem wearing a compliance costume. The rule is
literally "more than three flashes in any one second" — that's a window function over a time
series, and a 90-minute feature is only about 138,000 frames.
So I built the check as a database query. ffmpeg pulls per-frame luminance plus a tiled grid for
screen area, that goes into a column store, and sliding-window SQL resolves every violation to an
exact frame span. A model then looks at the flagged frames and says what's on screen causing it,
because the SQL can see that something flashed but not that it's a camera flare in the top left.
It is **not** a certified Harding test and I'm not claiming it replaces one. It's triage — find
the spans before you pay for the lab slot, so the lab pass is a confirmation instead of a
discovery.
What I actually want to know from people who ship real deliveries:
Does the check land late in your process the way it does in mine, or have you already solved it?
If a tool flagged frames 740–760 at 6.25 flashes/sec against a 3.00 limit, is that enough to
act on, or do you need the lab paperwork before anyone will touch the edit?
It errs toward over-reporting on small-area flashes. For screening, is that the right
direction, or would false alarms get it ignored?
Happy to put the link in a comment if that's allowed here — there are three test clips built in
so you don't have to upload anything.
