Case Study: S4C – A Public Service Innovation in Connected TV

CTV Platforms

S4C, the Welsh public service broadcaster, partnered with FX Digital to overhaul its Connected TV (CTV) presence. The broadcaster required a scalable solution that could meet stringent accessibility, compliance, and bilingual service standards, whilst performing reliably across a fragmented landscape of legacy and modern devices.

FX Digital delivered a complete rebuild using LightningJS, creating a modular architecture deployed across six platforms from a unified codebase. The solution delivered:

    • First-to-market bilingual audio support on Freeview

    • GDPR-compliant consent management

    • 70% automated test coverage across real devices

    • Accelerated rollout and certification on key platforms

By solving both technical and strategic challenges, FX empowered S4C to expand reach, enhance user experience, and uphold its public mission – setting a new benchmark in accessible CTV delivery.

About S4C

S4C is the only Welsh-language public service broadcaster, offering a diverse mix of content to audiences in Wales and beyond. With a growing digital user base and a responsibility to serve both Welsh and English speakers, S4C needed to modernise its OTT strategy to align with evolving viewing habits and accessibility standards.

The Challenge

S4C’s legacy app, developed on the Preact framework, was unable to reach certification for Everyone TV (formerly Digital UK), resulting in lost audience access and a breach of public service expectations.

But beyond fixing the Freeview issue, S4C needed to future-proof its entire CTV presence. The project required eliminating legacy technical debt and building a flexible foundation for multi-platform deployment with advanced feature support.

Core Pain Points:

  • Certification failure leading to platform exclusion
  • Device fragmentation, especially across older Freeview units
  • Mandated accessibility and bilingual service standards
  • Urgency to modernise without sacrificing reach or compliance

The Solution: A Unified, Future-Proof CTV Framework

FX Digital rebuilt the CTV suite from the ground up using LightningJS, a WebGL-based framework optimised for low-spec hardware. The solution was architected around a shared modular codebase, enabling scalable deployment across Freeview, Fire TV, LG, Samsung, Virgin Media, and YouView.

By focusing first on Freeview – the most technically constrained platform – FX established a robust foundation that scaled efficiently across higher-performance devices.

Key Solution Highlights

Modular Multi-Platform Architecture

  • Deployment time reduced from 18 months to 2 months for subsequent launches
  • Supported both legacy set-top boxes and modern smart TVs

Performance & Certification Strategy

  • Freeview-first optimisation ensured compliance with strict platform thresholds
  • In-person development and testing at Everyone TV’s Bedford lab secured approval across 90%+ of Freeview’s hardware base
  • Resolved historic certification blockers through targeted performance enhancements

New Incremental Revenue

  • Activated pre‑roll and mid‑roll ad delivery on Freeview and other legacy devices
  • Drove new incremental revenue by enabling advertising on platforms that were previously unable to serve ads.

Multilingual & Inclusive Features

  • First Freeview deployment to offer dual audio tracks for live content (Welsh/English)
  • Integrated subtitles, signed content in British and Welsh Sign Language, and dedicated signed-content navigation
  • High-contrast, WCAG-aligned UI with support for alternative inputs (LG Magic Remote, USB mouse)

Privacy-First Consent Management

  • GDPR compliance achieved via ConsentManager.net
  • Enabled seamless mobile control of preferences without disrupting on-screen UX

Advertising & Monetisation

  • Integrated FreeWheel to orchestrate pre‑roll and mid‑roll advertising across Freeview and all other supported platforms.
  • Unified ad behaviour (timeouts, tracking beacons, error handling, and adblocker fallbacks) within the LightningJS framework to keep playback resilient on constrained hardware.
  • Opened up monetisation on platforms that previously couldn’t surface ads, without compromising compliance or performance.

QA Automation at Scale

  • Custom automation framework delivering 70% test coverage across multiple CTV platforms
  • Vision-based regression testing executed nightly on Freeview (Humax Aura), Samsung, YouView (STB & Sony), and Fire TV devices
  • Reduced manual QA workload and increased release confidence across diverse hardware environments

Results

The S4C and FX Digital collaboration delivered measurable success across functionality, performance, and regulatory dimensions, redefining what’s possible for public broadcasters on Connected TV.

Efficient Multi-Platform Launch

  • Certified and deployed across Freeview, Fire TV, LG, with Samsung and others in final stages
  • Unified experience and feature parity achieved across all platforms

New Incremental Revenue

  • Enabled advertising delivery on previously unsupported legacy devices, unlocking new revenue streams for S4C
  • Introduced pre-roll and mid-roll ad placements via a custom FreeWheel + VMAP/VAST integration
  • Provided a scalable monetisation framework adaptable to new platforms without additional SDK dependencies.

Breakthrough Innovation

  • First known Freeview app with live bilingual audio support
  • GDPR solution set a new standard for consent handling in CTV apps

Enhanced Accessibility

  • Delivered signed video, multilingual subtitles, high-contrast UI, and input flexibility
  • Created a more inclusive experience aligned with PSB values

QA Excellence

  • Extensive automated testing ensured reliability across fragmented devices
    • Faster regression cycles and reduced defect rates

Strong client Endorsement

  • Multiple NPS scores of 9 or 10 from S4C
  • Praised for technical execution, communication, and proactive support

Looking Ahead

FX Digital’s partnership with S4C continues to evolve, with upcoming launches, on Virgin Media, and Sky (in development). Future focus areas include enhanced subtitle standards, advanced analytics, alternative input support, and integration with Freely for IP-based live TV.

This engagement demonstrates FX Digital’s broader capability to deliver high-impact, compliant, and future-ready CTV solutions. By combining bespoke frameworks with deep public broadcasting expertise, FX consistently navigates certification hurdles, legacy hardware, and fragmented ecosystems – cementing its position as a trusted long-term partner for broadcasters.

Optimising Your CTV Strategy

As streaming evolves, ensuring a seamless, high-quality experience on Connected TV is more important than ever. At FX Digital, we help content owners and distributors prepare for the future of media consumption by building and optimising CTV apps with cutting-edge test automation.

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