Cinema-Slate auto-connection approval for bluez and location-observe

store-requests privileged-interfaces
1

Dear Snapcraft Team,

We are requesting auto-connection approval for the following interfaces for our Snap package cinema-slate.

Name: cinema-slate Description: Cinema Slate is a professional digital clapperboard and production slate for film and video. It marks takes with an animated clap, generates and displays SMPTE timecode, maintains a shot log, and syncs timecode with external devices on set. Snapcraft: Not publicly available Upstream: PRIVATE Upstream-relation: The snap is published by the upstream developer.

Interfaces:

bluez

  • request-type: auto-connection
  • reasoning: The bluez interface is required to discover and communicate with Bluetooth timecode devices such as Tentacle Sync. Wireless timecode lock and jam sync are core Pro features of Cinema Slate; without Bluetooth access, users cannot connect these devices and keep cameras and the slate frame-accurate on set.

location-observe

  • request-type: auto-connection
  • reasoning: The location-observe interface is used to obtain accurate GPS-derived time for Time of Day timecode. Film sets rely on precise wall-clock sync across cameras and the slate; GPS time provides a reliable time reference when generating Time of Day timecode, which is a common and expected capability of a production slate.

Both interfaces are essential to Cinema Slate’s timecode workflow, and their auto-connection aligns with user expectations for a professional digital slate.

Please let us know if any further information is needed.

2

This request has been added to the queue for review by the @reviewers team.

3

Hello @navideck,

Given the described snap functionality, bluez inteface auto-connection feels like reasonable and expected access. As for location-observe, this feels like very broad access for the described usage and this is generally not granted auto-connection without being an explicit mapping service. Could you provide more detail surrounding the technical issues justifying the need for location access over using another clock source? Thank you!

4

@elisehdy the location-observe interface serves two purposes:

  1. Geotagging — Stores GPS coordinates for each camera take into metadata (via GeoClue → geolocator → GeotaggingService).

  2. Time of Day timecode — Derived from the system clock. GPS satellite time is the most accurate time source available (UTC from atomic clocks), and we need frame-level accuracy (~30–40ms at 24–30fps). Film sets often lack internet, so either way NTP is not an option. Requiring users to manually configure gpsd+chrony is unreasonable — GeoClue via location-observe is the standard Linux pathway for this out of the box.

Hope that clarifies things.

5

Hello @navideck, thank you for the expanded detail.

Given the functionality requirements, this is a +1 from me for granting auto-connect of the bluez and location-observe interfaces to snap cinema-slate. While the location-observe need is not obvious, I believe it is necessary access and manual-connect is not practical for an application like this. What do other @reviewers think?