julian
fa65b2df86
Replace the camera stub with HttpCamera: Hikvision ISAPI and Dahua CGI snapshots over client-side HTTP Digest (new drivers/http-digest.ts). healthCheck() now pulls a real frame instead of returning ready/stub. Snapshot carries bytes (driver fetches); storage/imageRef is the caller's job, keeping the adapter free of storage deps. Fix the cosmetic Backend-push-IP field: add pushesToBackend to DeviceDriver (only Dingtian sets it), expose as pushCapable in the catalog, and gate the wizard's backend-IP fetch + field on it so pull-only devices hide it. Verified on hardware (Hikvision 10.0.10.121): healthCheck ready, captureSnapshot returns a valid JPEG.
56 lines
3.1 KiB
Markdown
56 lines
3.1 KiB
Markdown
---
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type: entity
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tags: [parking, hardware, readers, offline-first]
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sources: [parking-system-architecture]
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updated: 2026-06-15
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---
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# LPR Camera
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License-plate-recognition camera (recommended: **Milesight edge-AI LPR**). For
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**casual/transient** vehicles, the **plate acts as ticket + an independent record**. (See
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[[parking-system-architecture]] §8, §9.)
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- **Edge AI**: recognition runs **on-device**, so it keeps working with no internet — fits
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[[offline-first]].
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- It's a **host-side** identity source: only the host sees the read; the host decides and
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commands the relay open (the [[uhppote-controller]] is demoted to a commanded relay for that
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lane). See [[entry-exit-readers]].
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- Being host-in-the-loop is **good for fraud detection** — you get two independent records (the
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host's signed [[append-only-event-chain]] entry + the controller's remote-open event) that
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should reconcile one-to-one; any mismatch is an anomaly.
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- Mounting: within ~15° of vehicle travel at a controlled chokepoint for best reads.
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## Snapshot driver (entry/exit fraud-control record)
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Separate from edge-AI LPR: the camera driver (`packages/devices/src/drivers/camera.ts`) does
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**snapshot-on-event** — the host pulls a still over HTTP when an entry/exit fires and stores it,
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referenced from the signed [[append-only-event-chain]] entry as an independent record. The camera
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**pulls, it does not push** — so it is NOT `pushesToBackend` and the setup wizard correctly hides
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the "Backend push IP" field for it (gated on the driver's `pushesToBackend` flag; only
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[[dingtian-relay]] sets it).
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- **Hikvision** uses **ISAPI**: `GET /ISAPI/Streaming/channels/<id>/picture` (`101` = ch1 main
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stream) with **HTTP Digest** auth. The "Enable Hikvision-CGI" toggle (Network → Advanced →
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Integration Protocol) is a *different* legacy CGI surface — **not** needed for ISAPI.
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- **Dahua** uses CGI: `GET /cgi-bin/snapshot.cgi?channel=<n>` (0-based channel; the wizard's
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1-based channel is decremented).
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**Driver / storage boundary:** the driver FETCHES the image bytes (client-side HTTP Digest in
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`drivers/http-digest.ts`) and returns them on `Snapshot.bytes`; **storage is the caller's job**
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(the future entry/exit flow stores the bytes + mints a durable `imageRef`). This keeps the device
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adapter free of any filesystem/blob-store dependency. `healthCheck()` is honest — it actually pulls
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a frame (exercising reachability + auth + path/channel in one shot), not a fake `ready/stub`.
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### Verified on hardware (2026-06-15)
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A **Hikvision** unit ("Camera 20", MAC `94:e1:ac:…`, Hikvision OUI) at `10.0.10.121`, creds
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`admin` / `admin123` (Digest), TCP 80:
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- Initial `curl` test confirmed the ISAPI path returns a 2688×1520 JPEG (~306 KB).
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- The **real driver** (no longer a stub) was then run end to end against it:
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`healthCheck()` → `ready` (pulled a frame), `captureSnapshot()` → valid `image/jpeg`, ~322 KB,
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correct JPEG magic. Digest handshake works through `HttpCamera`.
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- Reaching it from the WSL dev box required forcing the source address (`config.localAddress`,
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threaded into the driver) — see [[wsl-dev-networking]] (multi-subnet source-selection trap).
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