Hybrid-Log Gamma is set to be the future of broadcast
Two companies, Japan’s NHK and the UK’s BBC, have just taken one more step towards broadcast 4K HDR – it’s called Hybrid-Log Gamma.
The technology, which has been used to broadcast Planet Earth 2 in 4K to select Panasonic TVs via iPlayer, is nearly ready for primetime according to sources at the Digital Television Group (DTG).
In an interview with Inside CI, DTG’s Project Director AV, David Daniels, said that “the BBC has been privately testing UHD for some time, and this isn’t the first public trial – it provided last year’s Queens Speech in UHD. However, this is its first HDR/HLG trial so it is significant for the addition of High Dynamic Range, meaning the promise of delivery of so called “better pixels” can be tested in a real world environment.”
DTG, for those who don’t know, publish and maintain the technical specifications for broadcast TV in the UK so them adopting Hybrid-Log Gamma into its standards bodes well for the future of 4K HDR.
Speaking to Inside CI, Daniels said that the testing that’s currently taking place through iPlayer will “highlight any issues with backwards compatibility both in the displays that are currently in production, but also in the infrastructure available to deliver such services. There may well be unforeseen challenges in streaming such bandwidth hungry programming and any trial can only help us to find ways to overcome them.”
One of the biggest problems for broadcasting 4K HDR programming both in the UK and in the US and Australia is the bandwidth required to display that picture – a single minute of uncompressed 4K footage can be as much as 5.3GB.
But another problem the technology faces is that current HDR technology requires you to send two signals – one to HDR 4K TVs and one to SDR HD TVs.
What HLG promises is backwards-compatible signal that’s not only compatible with the latest 2016 TVs, but also older HD sets. Without it, TV broadcasters would have to transmit two separate signals, which would be over-complicated and expensive.
Should these tests go well, it will only be a matter of time before we see more channel operators take the necessary steps to broadcast their own networks in Ultra-HD HDR – a solid win for all of us who’ve invested in 4K TVs.