4K is the marketing term to cover what is officially named Ultra High Definition (UHD) video. UHD video is distinguished from current high definition video by having a higher picture resolution (more pixels) as well as more realistic colors and higher frame rates (meaning more pictures per second).
Let’s start with some definitions. 4K video is defined by the Consumer Electronics Association as a video stream that has at least 3,840 X 2,160 pixels. This contrasts to existing high definition (HD) video that has 1,920 X 1,080 pixels and standard definition video (SD) that has 720 X 480 pixels. These are not precise standards—for example there is some SD video that is broadcast at 540 pixels. There is also an existing standard for some video cameras that record at 4,096 X 2,160 pixels which is also considered 4K.
The 4K standard was developed in an attempt to be able to deliver digital media to movie theaters. This would save a lot of money compared to shipping around reels of film. Standard HD does not project well onto the big screens and 4K will overcome a lot of these shortfalls. But high action movies require more definition than is provided by 4K and will require the upcoming 8K video standard to be able to be digitally transmitted for use on the largest screens.
Interestingly, there is not a huge increase in quality from shifting home viewing from HD to 4K. There is a huge improvement in quality between SD and HD, but the incremental improvements between HD and 4K are much harder to discern. The improvements are more due to the number of different colors being projected, because the human eye cannot really see the pixel differences when viewed on relatively small computers or home TV screens. It’s easy to get fooled about the quality of 4K due to some of the spectacular demo videos of the technology being shown on the web. But these demos are far different than what run-of-the-mill 4K will look like, and if you think back there were equally impressive demos of HD video years ago.
The major difference between HD and 4K for the broadband industry is the size of the data stream needed to transmit all of the pixel data. Current 4K transmissions online require a data path between 18 Mbps and 22 Mbps. This is just below the FCC’s definition of broadband and according to the FCC’s numbers, only around 20% of homes currently have enough broadband speed to watch 4K video. Google just recently announced that they have developed some coding schemes that might reduce the required size of a 4K transmission by 40% to 50%, but even with that reduction 4K video is going to put a lot of strain on ISPs and broadband networks, particularly if homes want to watch more than one 4K video at a time.
I recently read that 15% of the TVs sold in 2015 were capable of 4K and that percentage is growing rapidly. However, lagging behind this is 4K capable settop boxes; anybody that wants to get 4K from their cable provider will require a new box. Most of the large cable providers now offer these boxes, but often at the cost of another monthly fee.
Interestingly, there is a lot of 4K video content on the web, much of it filmed by amateurs and available on sites like YouTube or Vimeo. But there is a quickly increasing array of for-pay content. For instance, most of the Netflix original content is available in 4K. Amazon Prime also has Breaking Bad and other original content in 4K. It’s been reported that the next soccer World Cup will be filmed in 4K. There are a number of movies now being shot in 4K as well as a library of existing IMAX films which fit well into this format. Samsung has even lined up a few movies and series in 4K which are only available to people with Samsung 4K TVs.
One thing is for sure, it looks like 4K is here to stay. More and more content is being recorded in the format and one has to imagine that over the next few years 4K is going to become as common as HD video is today. And along with the growth of 4K demand will come demand for better bandwidth.