# QRCode Clock — On Camera Decodable Clock

> On Camera Decodable Clock (iPhone/iPad app by Mark Gilbert.)

- Source: https://appshunter.io/ios/app/qrcode-clock/id6708236140 (this page in markdown: same URL + `.md`)
- Developer: [Mark Gilbert](https://appshunter.io/developer/593898292)
- Category: Photo & Video, Utilities
- Price: Free
- Age rating: 4+
- Requires: iOS 14.0 · 4 MB
- Languages: American English
- Released: 2024-09-27
- Data updated: 2026-08-12
- User reviews in markdown: https://appshunter.io/ios/app/qrcode-clock/id6708236140/reviews.md

## What is QRCode Clock?

* QRCode Clock is a tool for broadcast professionals to send local time to a remote Sienna ND Processing Engine system using a video stream of a camera pointed at the iOS device and thus present a QRCode of precision UTC time at the source.  This can be decoded by the Sienna ND Processing Engine to measure the total latency of the stream from the camera source all the way to the backend processing server.  This type of measurement is critical for tier 1 broadcast infrastructure. 

* QRCode Clock constantly checks accurate NTP time using time.apple.com to avoid clock drift in iOS.

*The App also outputs a local NDI stream showing the same QR Code so you can perform closed loop latency testing bypassing a camera.

* In addition to the primary purpose of measuring camera to server latency this app can be used as a general slate at the start of any recording which will provide a permanent time and date stamp for the recording, regardless of how it is copied or processed later.

* QRCode Clock also has an AV Sync Mode which displays a 1 second bar which fills over time, with a precise beep at the 0 mark.  This can be used to validate correct lipsync further down the process chain, after streaming, and used to measure then correct lipsync easily.


## Version history (last 1 release)

### 1.00 — 2024-09-27

No release notes.

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## More apps by Mark Gilbert

- [Strata Pro](https://appshunter.io/ios/app/strata-pro/id593898289)
- [Strata Lite](https://appshunter.io/ios/app/strata-lite/id594041964)
- [Strata View](https://appshunter.io/ios/app/strata-view/id594043002)
- [HyperRemote](https://appshunter.io/ios/app/hyperremote/id669079489)
- [WebNDI](https://appshunter.io/ios/app/webndi/id1073741051)
- [NDICam](https://appshunter.io/ios/app/ndicam/id1074065391)

All apps by Mark Gilbert: https://appshunter.io/developer/593898292

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-12.*