IP Studio In Action: Multi-Site R&D All-Staff Production
Once a quarter we hold an R&D all-staff meeting. This provides an opportunity for us to share highlights of recent work in different research areas and to communicate logistical and strategic information. Until recently BBC Research & Development was based at two main sites: one in West London and one at MediaCity in Salford. With the opening of new facilities near Euston Station in June this year, two have become three. You'll be pleased to hear that we don't all jump on a train every three months to travel to the all-staff. Up to now we've used an open source videophone system enhanced by engineers in the department to set up a video link between the two sites. But the addition of a third site has made our simple unicast videophone solution impractical.
This dilemma created an ideal opportunity to road test some of the technology we've been working on in the IP Studio team. The IP Studio Project aims to understand the benefits and challenges of using non-specialist computer hardware and IP networks in the TV studio by developing a set of software components that can be flexibly combined to make video and audio processing pipelines.
The challenge was this: Link MediaCity UK, Centre House and Euston Square with video and audio for a live event. The audience at each site must be able to see and hear presentations given from any of the three sites and to participate in Q&A sessions. The presentations may include powerpoint slides or videos.
Take a look at the video to see a tour of what we built:
So how did it all work? Camera feeds of audience and presenter from each site were multicast as RTP sessions onto the network. The HDMI output from the computer hosting the presenter's slides and video at each site was captured and multicast as an additional RTP session. All video feeds were streamed in both low resolution proxy and full resolution versions. Audio feeds from all presenter and audience mics were packaged with the audio from the video playout computer and sent as a multichannel RTP audio session.
At each site we installed a small production "gallery" comprising IP video multiviewer, audio mixer and vision switcher control panel. Large screens were placed at the front and the back of the room. These were used to display live video feeds of remote presenters, slides and remote audiences, with the experience tailored for each site by the local production staff. The audio mixer at each site fed a PA system to reproduce the audio from remote sites and to provide local sound reinforcement where necessary.
The vision switcher control panel is a simple web application that accesses web services on the IP Studio RTP Receiver components feeding the large screens to change their multicast subscription. Reception of proxy video streams by the multiviewer and reception of audio streams were statically configured.
Talkback between production personnel on all sites was also carried on the IP infrastructure. For convenience this was implemented using conferencing features on VOIP telephones which were fitted with headsets. An overall director for the production was employed to coordinate the teams on the three sites, communicating the running order, cueing cameras and sound and making suggestions about shot choices to be displayed on the screens in each location.
What we achieved was a working distributed production environment, with three sites separated by hundreds of miles each enabled to produce their own local version of a live event in parallel from shared video and audio elements. Feedback from audience and production personnel involved was positively enthusiastic.
As well as solving a tricky logistical challenge, putting on this show has been a valuable learning experience. It's taught us which of our software components are robust and which need more work. It's also sparked a shower of new ideas about potential optimisations and enhancements. By putting these ideas into practice we'll ensure that next time it will be quicker to set up and we'll be able to produce a slicker, richer experience for the all-staff audience, presenters and production personnel.
For now, this successful trial is a small but important step towards proving that IP networks can be used in a real live TV production environment. For the future this approach could unlock new levels of flexibility, agility and new audience experiences in the world of broadcast.