BBC Post Production in partnership with Siemens Business Services has transferred HD media between BBC sites for the first time without the need for dedicated HD circuits, writes Fergal Ringrose.
Utilising a combination of Avid DNxHD compression, the existing SD infrastructure inside each building and new fibre connectivity between Bristol Broadcasting House and London Television Centre provided by Siemens Business Services, HD material was moved between BBC Post Production's Bristol machine room and London eQ Suite.
Avid DNxchange compression technology reduces high bandwidth HD-SDI down to an SDTI bit stream capable of being carried by existing SDI circuits. Decoding back to HD-SDI allows the HD signal to re-enter the native HD infrastructure that supports BBC Post Production's HD production village in Television Centre.
In a further step, the raw DNxchange bit stream was routed via Avid AirSpeed into one of BBC Post Production's Avid Unity/Avid Media Composer Adrenaline systems. Using the Frame Chasing ability of the system it was then possible to start editing the incoming HD material within seconds of its arrival.
The experiments carry significant implications for future HD tapeless workflows and may form the foundations of a practical method of moving HD between sites at short notice in the immediate future. Clive Hodge, Head of Operations BBC Post Production: "By pushing the boundaries of the existing technology, we have demonstrated a method to enable content creators to rapidly transfer HD media for effective working. DNxHD is one of a number of compression technologies available however our familiarity with it as part of the post production process is an advantage as is the compatibility with some of our existing HD editing systems. The fact it utilises the current SD infrastructure, without the need for expensive HD lines, means that it is cost effective too."