As we slowly move away from the now-dated 1080p into the brand new crisp era of the 4K, the issue of connectivity is surfacing beneath the promising benefits the 4K will bring. Most predominant issue is interconnectivity, the question of how our 4K devices will interact with each other in an easy set up with no hassles.
Despite the level of innovations presented by the 4K displays itself, the connectivity is only catching behind. The first generation 4K displays could only offer HDMI 1.4 connectivity. HDMI 1.4 however, despite its qualities, could not deliver original 4K content beyond 30fps. It could also not do 3D at 4K, which is a big let down considering the great opportunities 4K has to offer.
This is where the HDMI 2.0 comes into play, to deliver what 4K truly has to offer in terms of viewing experience. This statement, as astonishing as it sounds, however, does not exactly hold true. For instance, consider the proliferation of 4K displays today. Despite many screens claiming to offer true 4K resolution, the reality is unfortunately far from it, at least for now. HDMI 2.0 is currently living a similar drama, with manufacturers announcing new connectors left and right despite the lack of true 4K support.
Many HDMI 2.0 connectors available today doesn’t have the right capabilities to handle 4K images at every aspect ratio. Home Theatre Review website has few ideas why HDMI 2.0 fails to deliver what it promises right now.
COLOUR COMPRESSION IN 4K
The colour space compression comes out as the first problem with current HDMI 2.0 compatibility. Currently there are three compression options; 4:4:4 (less compression, highest quality), 4:2:2 and 4:2:0 (most compression, lower quality). In order for HDMI chips to be officially compatible with 4K, they could just offer 4K image on 60 frames with only 4:2:0 compression, which would require a bandwidth of 8.9 Gb/s. This bandwidth, although seems plausible, is far below what 4K can truly deliver, which is 60 frames at 4:4:4 compression, requiring 17.82 Gb/s.
As many additional performance levels are only optional for the HDMI 2.0 specification, chipset manufacturers can claim 4K & HDMI 2.0 compatibility. As the production costs of HDMI 2.0 chips lowering; we’ll probably see a similar adaptation by the market to full bandwidth HDMI 2.0 capabilities. We are already seeing new specifications on the Ultra HD Blu-ray side, which promises lower compression of colour space. In the coming years, we are hoping to see full market adaptation of HDMI 2.0 to offer 4:4:4 compression.
The performance drawbacks of current HDMI 2.0 connectivity does not stop at colour compression. The second problem is HDCP, the copy protection system between HDMI interfaces. The HDCP specifications require that every component of a system, let it be TV or Blu-ray player, has to be on the same specification level, which is currently on iteration version 2.2. First generation 4K displays failed to support the 2.2 standard due to unavailability at the time. With the HDCP 2.2 specifications recently being revealed, we should expect many of the upcoming entertainment components to support this new specification. Until then, however, it’s the best practice to make sure that every component of your entertainment system is HDCP 2.2 compatible to prevent future frustration.
2015 will possibly be the biggest leap in the electronics to adapt 4K with widespread component compatibility. The great product announcements at CES 2015 was the strongest indicator of this growing trend. All in all, we are excited to see how the high bandwidth of HDMI 2.0 will play out in capturing the true potential 4K aims to deliver.