Broadcasting in 8K

Thursday, June 25, 2020 12:06

The move to 8K content is fast approaching. Home audio and video setups are quickly becoming capable of cinema-quality experiences. But what does it truly take for modern engineers to produce 8K broadcast content? And how ubiquitous is the market truly going to get?

This article explores the Ultra HD revolution, along with everything engineers and other production professionals need to know to adapt to the changing market. This is your guide to the world of 8K video.

What is 8K?

An 8K UHD TV has a display resolution of 7680x4320, and more technology capable of recording, storing and broadcasting it is hitting the market every day. This standard is defined in SMPTE ST 2036-1, and it contains four times the pixels of a 4K resolution. Frame rates can also reach 120/1.001, making it an ideal gaming resolution.

Although the consumer market for 8K video is relatively small right now, it’s expected by market analysts to reach 31 million sales by 2025. It’s not just growing in the TV market either – both Sony and Microsoft announced 8K compatibility for their next-generation PlayStation 5 and Xbox Series X video game consoles. Samsung’s latest Galaxy S20 line-up supports 8K too. When paired with a high-resolution audio track using a 48kHz sample rate and up to 22.2 audio channels (vs 5.1 available in 1080P HD), 8K has immersive realism that’s even perfect for VR.

Transmitting 8K content relies on codecs, and the HEVC/H.265 codec has been used for the past decade to ensure high-quality audio and video can be transmitted over existing data lines. As broadcast television loses its place on the wireless spectrum to make way for more 5G wireless communications, the path is being laid for 8K to dominate the airwaves.

Requirements for 8K broadcast

The biggest problem faced in widespread 8K distribution is the limitations of current broadband internet connections. One minute of 8K uncompressed video is around 6 GB of data. As most cable or DSL connections take a lot longer than 60 seconds to download a 6 GB file, streaming would not be possible. This is where the compression algorithms above come in, along with new technologies under development.

Japan’s 8K satellites, for example, were launched in December 2018 to broadcast HEVC using a newly developed ISDB-S3 transmission system and 16APSK modulation scheme. These broadcasted bands are secured using left-handed circularly polarized (LHCP) radio waves in addition to the RHCP waves already used in Japanese satellite broadcasts, effectively forcing home receivers to be upgraded for wide band IF.

Due to the technology used, both 4K and 8K signals can be broadcast without interference from existing 2.4-GHz Wi-Fi devices. Japan and SMPTE’s technical standards for 8K broadcast are just the beginning – even Samsung is jumping into the fray, using deep learning to create an adaptive codec powered by artificial intelligence (AI) called ScaleNet. This AI codec effectively compresses 8K quality through downscaling for a smaller transmission, then upscales at the source for a crisp and clear UHD image.

While bandwidth is limiting 8K production and broadcast right now, that doesn’t mean it’s not on the way. These signals are easily downscaled to 1080p resolutions to accommodate users who don’t have capable displays. As the compression and display technologies become more commonplace, consumers are going to expect a more polished UHD product, so future-proofing content is necessary.

The future of 8K audio and video Production

It’s not just satellites where Japan is leading the 8K charge – its production studios are highly focused on UHDTV content. In fact, a serial digital interface/internet protocol (SDI/IP) hybrid is used to ensure 8K is integrated into its current array that’s focused on both 2K and 4K content. Testing started back in 2016, and additional 8K compatible studios were added entering the 2020s. These studios enable UHDTV signals to be edited and broadcast for sports and other events.

The studio uses 12G-SDI cables and routers, mixed with large-scale compression that reduces the file sizes to about a third of the original size. The SDI output is passed through an IP gateway and then fed into the downstream keyer and audio multiplexer for proper editing and monitoring through your network media interface. Of course, even Sony’s NMI only supports 4K, so the 8K stream is split into four streams viewable on four 4K monitors.

These setups can be complicated and expensive for many studios to adopt, so it’s typically integrated into the existing structure. A single 8K monitor can be combined with existing 4K and 2K monitors for a more organic 8K studio production.

Although 8K isn’t the standard right now, it will be soon. It’s also expected by early adopters and professionals. Even if the 8K capability isn’t used in a camera or broadcasting board, it still improves the quality of a 4K broadcast. Increased sharpness, clarity and refresh rates make for an overall improved viewing experience that may well end up becoming the new bar for every content creator to overcome.

Major problems involving the introduction of 4K video performance have been mostly resolved since it became the new U.S. broadcasting standard in 2017. The shift to 8K represents the next step in this constantly evolving industry. It’s necessary to make televised events like the Super Bowl or NCAA Finals feel immersive and realistic, to improve the graphics on video games and to make virtual reality experiences visually passable.

How you prepare for this new normal will have a large impact on your ability to reach viewers moving forward.