Throwback Thursday: From 320×240 to 4K
In a few weeks I’m speaking at Streaming Media’s Streaming Forum on the panel Is HD the Real End of the Line for Quality? In advance of the conference, I’ve been asked to share my thoughts on whether 4K will ever become widespread.
Video in the ’90s: 320 x 240
As it’s a Throwback Thursday, let me first take you back in time to the early 1990s. I was working at IBM on the beginnings of multimedia and video technology for the PC. Have a look at our video showcasing our the quality of our technology!
We were exceptionally proud of playing video at 320 x 240 x 256 colours x 15 frames per second. But what did that really mean for us back then?
So that 320 x 240 movie with 8-bit colour (256 colours) recorded at 15 frames per second produced a raw movie file that would require a data rate of 1,125 kilobytes (KB) per second (KB/s) (or 9,000 Kbit/s or 8.79 Mbit/s).
The associated audio back then was recorded at 11.025 kHz, 16-bit, and mono — this added another 21.5 KB/s.
That brought the aggregate the data rate to an “impractical” 1,146.5 KB/s. To play back that video at the average data rate of a single-spin CD-ROM – 150 KB/s – required a nearly 8:1 compression ratio.
Welcome to CODECs – COMpression / DECompression technology. Because it was processor intensive, we started with hardware-assisted compression and decompression. But we were eventually able to move to software-only, especially for decompression.
Video in the ’10s: 4K
Now how many of you think watching video at 320 x 240 x 256 colours x 15 frames per second is just silly? I mean, you’d never do that nowadays, right? Not even on your smart phone. But that was bleeding edge 20 years ago. And a technical challenge. Which we overcame.
So 4K. A picture says so much, so here’s a scale comparison of all the resolutions, from where we came from to where we’re going to. And that doesn’t even cover 8K and beyond.
That’s clearly a lot more data to both store (bytes) and deliver (bits), and it’s more than just a change in resolution. The colour bit-depth has also increased, as has the frame rate, and there’s interlaced versus progressive scanning. Just as CD-ROM speeds increased, terabyte (TB) storage prices are decreasing and in some territories we’re starting to see gigabit (Gb) broadband.
But what about compression / decompression technologies? Well, the pairing to 4K is High Efficiency Video Coding (HEVC), otherwise known as H.265, the successor to H.264 (MPEG-4 AVC). HEVC is supposed to be twice as good as H.264, which is today’s standard for HD delivery. But, HEVC is, guess what, processor intensive and requires hardware right now. Sound familiar? If you think this sounds like where we found ourselves 20 years ago, you’d be right.
4K and the consumer perspective
So what does this mean to the end consumer and will it see widespread adoption?
Well, you’re going to need a new telly, and the newer ones will probably have a hardware decoder for HEVC. Unfortunately the older ones don’t have a hardware decoder, which means some content won’t work. And the TV will be bigger to make it worth having all those extra pixels. The minimum seems to be about 55″. So there’s something new to consider as well — viewing distance. As the screen gets bigger, it needs to be farther away to see the whole screen, although how far depends on the aspect ratio. So you need both a bigger wall for the screen and a bigger room to view it in.
The good news is a lot of films and some television is now being mastered in 4K or above, if only for archive purposes and higher quality HD to begin with.
Delivery of 4K is starting. Netflix is now streaming House of Cards in UltraHD at 15.6Mbit/s to 4K TVs with a built-in hardware HEVC decoder. Not good news for those TVs without a hardware decoder. There’s also content on YouTube. Sony and Samsung (coming up) have 4K video players and high-capacity optical discs are in development.
So both technology and content are moving in the 4K direction. Widespread adoption will be based on how much value that adds to content enjoyment, cost and ease of use.
Find out more
For more on the history of video technology, read the video section on Maria’s chapter on OS/2 Multimedia.