Canal Overseas simplifies operations with Wohler closed-captioning solution
April 24, 2008
Canal Overseas, a division of French broadcast group Canal+, is using the Wohler Technologies HDCC-200A HD/SD-SDI closed-captioning bridge to handle and store World System Teletext (WST) subtitle data within its HD/SD playout infrastructure.
SysMedia, a UK-based systems integrator, provided the Wohler unit, which enables Canal Overseas to store teletext subtitle data with ingested HD content in such a way that content does not also need to be stored in an SD form.
Canal Overseas uses six HDCC-200A units to embed WST data in the HD-SDI signal (VANC) during ingest. Six programs are simultaneously recorded from external HD feeds with SD and the VBI-related signal from external SD feeds upconverted during the ingest process. Alternatively, HD tape programs with EBU subtitle files are stored on an HD broadcast server.
On playout, Canal Overseas uses 16 HDCC-200A bridges to extract the HD-VANC data and re-encode it as conventional VBI teletext subtitling into a parallel SD-SDI signal downconverted from HD. The SD-VBI subtitles are then displayed for local monitoring (preview channels), converted into DVB teletext subtitles on the downconverted SD transmitted channels or converted into DVB subtitling on HD-transmitted channels.
This solution, installed at Canal Overseas HD facilities outside Paris, simplifies playout of various programs on 14 different channels transmitted by satellite to West Africa, Polynesia, the Caribbean, Caledonia, Reunion and Mauritius. The system allows Canal Overseas to store content only in HD, rather than both SD and HD, while maintaining playout in both formats. For more information, visit
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