When moving to an HD-SDI only link between playout and distribution, Canal+ has chosen the new OP-47 modules in Cavena's Subtitle Transmission Unit, STU, to carry subtitles from the playout to the distribution centre. Subtitle are encoded at playout to OP-47 and inserted into VANC in the HD-SDI signal. At the receiving end, the data is extracted and transcoded to DVB and teletext subtitles. The modular upgrades to the STUs allows Canal+ and CanalSat to continue building on their existing systems and implement a very cost efficient upgrade path to HD-SDI.