S4C on Freely: How a local broadcaster delivered a complex live TV workflow with AWS Elemental Media Services

This article details how S4C, a Welsh-language broadcaster, built a live TV streaming pipeline using AWS Elemental Media Services to deliver content on Freely, the UK's free-to-air streaming platform for connected TVs.

• S4C implemented a four-stage AWS pipeline: Elemental Live encoding, MediaPackage packaging, MediaTailor ad insertion, and CloudFront delivery
• Pipeline meets Freely's technical requirements: DVB DASH adaptive streaming, EBU-TT-D subtitles, and accessibility metadata
• Supports multi-language audio tracks (English, Welsh, Welsh audio description) with frame-accurate segment alignment
• Integrated FreeWheel ad decision server for server-side ad insertion with personalized advertising
• Custom transcode profile handles multi-language ad delivery and embeds Kantar audience measurement markers
• Preserved ad markers throughout pipeline from playout system to final delivery
• Small engineering team successfully deployed complex streaming infrastructure without custom development

S4C's implementation demonstrates that broadcasters can meet modern streaming requirements through integrated AWS media services, regardless of team size.