Canal Overseas, a division of leading French broadcast group Canal+, is using the PANORAMA dtv HDCC-200A HD/SD-SDI closed-captioning bridge to enable efficient handling and storage of World System Teletext (WST) subtitle data within an HD/SD playout infrastructure.

By encoding subtitles within an HD ingest workflow and subsequently decoding those subtitles back at the time of playout, this new card supports a single cost-effective video ingest and playout workflow regardless of the availability of subtitles. It also adds to the bottom line by eliminating the need for duplication of SD and HD video storage.

"The teletext data solution provided by Wohler perfectly met our project's functional specifications and constraints," said Gino Ma-Paw Youn, technical manager at Canal Overseas. "We were searching for an innovative solution for managing WST subtitles with HD material, and the Wohler closed-captioning bridge helped us optimize this process within our new HD broadcast facilities. The Wohler system is easy to implement and use, and we consider it to be the most efficient, cost-saving solution with respect to our needs."

Canal Overseas uses 11 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, or from HD tape programs with EBU subtitle files and subsequently 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 either 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 cost-saving system allows Canal Overseas to store content only in HD, rather than both SD and HD, while maintaining playout in both formats. A spare kit, including two additional Wohler units, provides backup for the broadcaster's subtitling operations.

"Our HDCC-200A product is designed to provide flexible encoding and decoding of closed-caption data for media companies working in any broadcast standard," said Carl J. Dempsey, Wohler president and CEO. "The HDCC-200A is the product of extensive work with Europa Australia's Elio Deluca, one of the world's preeminent experts in the field of closed-captioning. The installation at Canal Overseas demonstrates the efficiencies the resulting signal processing technology can bring to European broadcasters working in both SD and HD."