BBC R&D’s IP Studio: Live production of big TV events in a web browser
Wednesday, 07 June 2017
Interested in cloud-based high end post production? Live events and TV shows need live production. A post on the BBC R&D blog explains the challenges of making a system that can do live TV production in a web browser.
They are basing their research on a system ‘IP Studio’:
…a platform for discovering, connecting and transforming video streams in a generic way, using IP networking – the standard on which pretty much all Internet, office and home networks are based.
No buffering allowed:
It’s unacceptable for everyone watching TV to see a buffering message because the production systems aren’t quick enough.
Production systems (and their IP networks) must be able to handle 4K streams - even if final broadcast is viewed at lower resolution:
We’re not just transmitting a finished, pre-prepared video, but all the components from which to make one: multiple cameras, multiple audio feeds, still images, pre-recorded video. Everything you need to create the finished live product. This means that to deliver a final product you might need ten times as much source material – which is well beyond the capabilities of any existing systems.
The trick is dealing with time. All the varying delays from hardware and software have to be synchronised.
IP Studio is therefore based on “flows” comprising “grains”. Each grain has a quantum of payload (for example a video frame) and timing information. the timing information allows multiple flows to be combined into a final output where everything happens appropriately in synchronisation. This might sound easy but is fiendishly difficult – some flows will arrive later than others, so systems need to hold back some of them until everything is running to time.
The production setup has to be able to deal with all this data, so browser-based switching and mixing software has to be tuned to fit the PC/tablet/phone it is running on and the servers it interacts with:
…we are showing lower resolution 480p streams in the browser, while sending the edit decisions up to the output rendering systems which will process the 4k streams, before finally reducing them to 1080p for broadcast.
Find out more at the BBC R&D blog.