Understanding ULTRA HD

Resolution – According to the CEA

An Ultra HD TV must support a minimum pixel count of

3840 Horizontally2160 Vertically

The other resolution standard - DCI

4096 Horizontal2160 VerticalDigital Cinema Initiatives, LLC (DCI) was created in March, 2002, and is a joint venture of Disney, Fox, Paramount, Sony Pictures Entertainment, Universal and Warner Bros. Studios.

Colour Sampling

Colour sample ratio refers to the ratio of luma (Y′) samples to each colour difference sample (CB and CR). For example, 4:2:2 colour sampling means that for every four pixels of Y′ data stored, only two CR samples and two CB samples are stored. By reducing the number of chroma samples, less colour detail is recorded and less bandwidth is required for storage and transmission. Because we are less sensitive to colour detail than we are to luma detail, subsampling the chroma signal can be considered perceptually lossless.

Sample Ratios

Sample ratio Description4:4:4 Each R, G, and B channel, or each Y , CB, and CR channel, is sampled at the same rate. Maximum colour detail is maintained.′

4:2:2 The colour channels are subsampled so that the colour resolution is halved. For example, the first pixel in a line contains Y , CB, ′and CR samples. The next pixel contains only a Y sample. This pattern repeats. Most professional video formats use 4:2:2 colour ′subsampling.

4:2:0 This ratio indicates that the CB and CR channels are subsampled both horizontally (as in 4:2:2) and vertically. This reduces colour resolution in both the horizontal and vertical dimensions compared to 4:2:2, which only reduces horizontal chroma resolution.There are several methods for locating CB and CR samples relative to Y samples, yielding several different 4:2:0 formats.′

Bit Depth

The number of bits used per sample determines how accurately the sample is stored, as well as how much intensity variation is possible within the signal. For example, a video signal with a bit depth of only 1 bit can have a value of either 0 or 1, resulting in only black or white pixels. Two bits per sample results in four possible values: 00, 01, 10, or 11, or any of four shades of grey (or some other colour) per sample.

Perceptual Coding and Gamma

The limited number of brightness steps in 8-bit digital video requires efficient use of the 256 available codes. Because perception of brightness follows a power law function, humans are more sensitive to absolute intensity changes in dark areas. In other words, the amount of light required to make a perceptual shift in brightness increases exponentially. Therefore, a gamma correction is applied to video so that the step between each code represents a perceptual shift in brightness.

Frame Rate

Think of a motion picture camera as a relentless still camera, taking many still photographs every second. Movies create the illusion of motion by showing still images in rapid succession. The number of images photographed per second is referred to as the frame rate of the movie and is measured in frames per second (fps). Frame rate describes both the speed of recording and the speed of playback.

The Society of Motion Picture and Television Engineers

The Oscar® and Emmy® Award-winning Society of Motion Picture and Television Engineers® (SMPTE®), a professional membership association, is the preeminent leader in the advancement of the art, science, and craft of the image, sound, and metadata ecosystem, worldwide.

Film VS TV

Almost all films (The Hobbit: An Unexpected Journey is one of the few exceptions) are filmed at 24fps.

TV and especially sporting events do not respond well to the “Film Effect” of 24fps and are exclusively transmitted at 50fps in Europe and 60fps in America.

Bandwidth Requirements

Available Bandwidth

Copy Protection

Along with new and higher bandwidth requirements, commercially available 4K content will be encrypted with a new technology

HDCP 2.2

WHY?

• HDCP Master Key Confirmed; Blu-ray Content Vulnerable• BY MARK HACHMAN• SEPTEMBER 16, 2010 07:00PM EST• The leaked HDCP master key protecting millions of Blu-ray discs and devices that was posted

to the Web this week has been confirmed as legitimate, Intel representatives said late Thursday.

The leaked HDCP master key protecting millions of protected devices, including Blu-ray drives, that was posted to the Web this week has been confirmed as legitimate, Intel representatives said late Thursday.The disclosure means, in effect, that the content flowing over the encrypted HDMI connection may be recorded and authenticated using an unlicensed device.Intel spokesman Tom Waldrop said after two days of investigation, the company had informed its partners and licensees that the key, which was posted online on Tuesday, was indeed legitimate."We have tested this published material that was on the Web," Waldrop said. "It does produce product keys... the net of that means that it is a circumvention of the code."