Universal HbbTV MediaSync App | Second Screen Synchronisation

Experience it in Seconds

Enjoy synchronized second-screen content effortlessly.

Step 1: Discovery

Step 2: Choose Track

Step 3: Playback

The app can offer alternative audio, additional video, sign-language video, or other second-screen experiences, depending on what the broadcaster makes available.

Zero-Friction Deployment

Zero custom apps to build or maintain. Zero backend to run. Zero complex infrastructure to configure.

Broadcasters only need to add a lightweight HbbTV snippet that points to the companion DASH MPD. The app handles the rest: it discovers the TV on the local network, loads the manifest, and synchronizes with the TV content in real time.

dns No backend to run

movie No media-file changes

bolt Near-zero configuration

verified HbbTV standards-based

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Use Cases: Unlocking Next-Gen Multi-Device Experiences

Demonstrate the practical value of HbbTV MediaSync by delivering seamless, personalized, accessible, and immersive services without any friction for the viewer.

headphones

Personalized Audio Experiences

Private Listening
Alternative Audio Languages
High-Fidelity Audio

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Universal Accessibility

Alternative Audio Tracks
Audio Description on Smart Glasses
Sign Language on Second Screen

devices

Home Mobility & Enriched Content

Private Views & Continuity
Alternative Camera Views
XR & Next-Gen Ecosystems

Another use case in mind?
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Application Capabilities

Key built-in features engineered for seamless companion screen experiences.

language

Available in 7 Languages

The app interface comes pre-localized in 7 languages: Catalan, Spanish, Basque, English, German, Italian, and French.

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Background Audio

Minimize the application or lock your device while keeping the fully synchronized audio track playing in the background.

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Fullscreen Video

Expand complementary video tracks, alternative angles, or sign-language feeds into a fully synchronized fullscreen view.

What happens under the hood?

MediaSync keeps discovery, manifest parsing, user choice, and playback timing in one continuous flow, so the companion device can render the right component at the same programme time as the TV.

1

The mobile scans for MediaSync devices

The app searches the local network for HbbTV terminals that advertise MediaSync capability.

2

The TV publishes the target MPD

The HbbTV app enables MediaSync and shares which DASH MPD the second device should receive.

3

The mobile reads the manifest components

Once it receives the MPD, the app parses every available component: audio, video, accessibility, language, and role metadata.

4

The user chooses what to watch or hear

Viewers select the component they need, from an alternate audio track to a sign-language video or companion feed.

5

DVB-CSS keeps playback within 20 ms

CSS-CII, CSS-WC, and CSS-TS endpoints align the second device to the TV timeline with less than 20 ms of delay.

Community Driven Innovation

Maintenance is open and community-driven. Any HbbTV member is welcome to propose and contribute new features to the core repository.

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Pull Requests

Contribute bug fixes or new device discovery adapters.

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Report Issues

Help us identify interoperability challenges across terminals.

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Discussion

Join the HbbTV working groups to define the future of second-screen.

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Frequently Asked Questions

Everything you need to know, whether you watch or you broadcast.

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For Users

How do I use the app? expand_more

On Android, download it from Google Play. Open the app while on the same Wi-Fi network as your TV: it automatically discovers the television, loads the companion content and synchronizes with what is playing on screen. No setup, accounts or pairing codes required.

Which TVs are compatible? expand_more

In theory, any TV supporting HbbTV 2.0.1 or later (from 2016 onwards) should work. In practice, some devices still have interoperability issues. We are building a list of verified compatible devices — if your TV works well, let us know so we can add it.

My TV is not working — what can I do? expand_more

If you run into a problem, please open an issue on GitHub describing your device and the behaviour you see. It helps us track interoperability problems across terminals and improve support.

Which channels and services can I watch? expand_more

The app works with services that broadcasters have enabled for second-screen sync. We will publish a list of compatible services soon so you know where to look.

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For Broadcasters

How do I activate the service? expand_more

Add a lightweight HbbTV snippet to your service that points to the companion DASH MPD. There is no backend to run and no media-file changes required — the app discovers the TV, loads the manifest and synchronizes in real time. Need help getting started? Contact us.

What is supported right now? expand_more

Over broadband, any service that uses an MPD manifest is supported: live streams (with and without DVR), VOD, and audio on demand.

Do I need to maintain a custom app? expand_more

No. The Universal MediaSync app is shared across all broadcasters, so there are no custom apps to build or maintain, no backend to run, and near-zero configuration.

Can I fork it and ship my own branded version? expand_more

The project is open source (MIT), so technically you can fork it and build your own branded version. However, we believe a single, shared app across all broadcasters is far more valuable for users — one app to discover and sync with any service, instead of a separate app per broadcaster. We encourage joining the common effort rather than fragmenting the experience.