Transition Minimized Differential Signaling (TMDS) is the algorithm that underlies both DVI and HDMI digital video interfaces, and is an output option in DisplayPort ++ (dual mode DisplayPort, aka DisplayPort 1.2) enabled devices. TMDS is a foundational element of contemporary A/V integration and needs to be a familiar concept to anyone involved in the design, installation or deployment of presentation systems.
Ultra HD is part of the next generation of video technology. Today we watch high definition video content in a format known as 1080p. This means that the image has 1080 horizontal lines of pixels (picture elements) stacked on top of each other in a manner roughly analogous to the logs in the wall of a log cabin. There are 1920 individual pixels (think “dots”) lined up next to each other on each scanning line. We often refer to this as a 1920 x 1080 image.
If we multiply 1920 pixels times 1080 scanning lines we come up with 2,073,600 discrete pixels composing the image. Therefore there are approximately two million “dots” making up the picture you see. The “p” in 1080p indicates a progressive scan implementation wherein the full frame of pixels is shown 60 times (50 times in Europe) every second. This system is sometimes referred to as a D2K image (D for digital and 2K for approximately 2,000 pixels in each horizontal scanning line).
When we try to move to even higher definition pictures, we keep the same relationship but increase the pixel density. The industry is now moving towards the widespread adoption of D4K (standards also being developed for D8K) images. Roughly speaking, a D4K picture (sometime written as simply “4K”) has twice as many pixels in each horizontal scanning line, and twice as many horizontal scanning lines. Following the same logic used above, a D4K image has 2,000 scanning lines composed of approximately 4,000 pixels each resulting in (2,000 x 4,000 = 8,000,000) about eight million pixels of resolution, four times the resolution of today’s already outstanding HD televisions.
Several 4K resolutions exist in digital television and digital cinematography. In October 2012, the Consumer Electronics Association (CEA) announced that the official term “Ultra HD” would be used for any display with a 16 x 9 ratio with at least one digital input capable of a minimum resolution of 3,840 x 2,160 square pixels. This delivers a stunning 8.3 megapixels (8,294,400 to be exact) with a widescreen aspect ratio of 16:9. Ultra HD images are only delivered in a progressive scanning manner (there are no official interlaced D4K standards) at frame rates of 120p, 60p, 50p and 30p.
While we will have to integrate new source devices that can generate these terrific data rates with a new generation of flat panel LCD and projection displays, we won’t be seeing any new connections. D4K and Ultra HD content is supported by HDMI, DisplayPort ++ and HDBaseT connections.
This article was written by Joseph D. Cornwall, CTS-D (Technology Evangelist — Lastar, Inc.) and originally appeared on C2G. You can view the original article here.