VGA, D-SUB, Div (-a,-D,-I), HDMI display/TV interface full explanation

VGA and D-sub are analog interfaces, while DVI and HDMI are digital interfaces.

DVI digital interface
D-sub is the analog signal interface.
The digital signal is more precise than the analog signal, so the DVI interface has a higher definition.

DVI explanation:
DVI-A: it is the same as VGA specification, including the analog interface of the rgbhv signal line.
RGB is the red, green, and blue signal, and HV is the line synchronization and field synchronization signals of both water and vertical scanning.
VGA interface specifications also provide rgbhv, so the DVI-A is compatible with VGA interface.

DVI-D is the real digital signal transmission.
DVI-A is just the definition of changing changes. It is actually the VGA Interface Standard.
DVI-I is integrated with the above DVI-A and DVI-D interface of the general term.

There are obvious differences between the three DVI Connector pins.

DVI-A (A = analog) is a analog signal interface, can only be connected to the DVI-A or VGA interface signal.
DVI-D (D = digital) is a digital signal interface, can only be connected to the DVI-D interface signal.
DVI-I (I = a + D = integrated) and the above two interfaces, when the DVI-I is VGA, is the DVI-A; when the DVI-I is DVI-D, DVI-D.

In addition, DVI-A and DVI-D are not mutually compatible/universal. The DVI-D can use an interface for the DVI-I.

Explanation of HDMI:
Similar to DVI interfaces, but containing all video and audio connection signals. Transmission of high definition digital TV signals for HDTV.
HDMI = video + HDCP + audio (digital video, copyright protection, digital audio ).
For backward compatibility considerations, HDMI is compatible with DVI, so there are many feasible solutions, such as DVI-D signals from the video source (HTPC, DVD player, set-top box, etc, collects the audio signals from other sources and connects them to the HDMI interface of the terminal.
You can also separate the video and audio signals at the HDMI interface of the signal source to provide your audio and video terminals separately.
HDMI supports standard, enhanced, and high-definition digital TV videos, as well as standard stereo, multi-channel surround stereo digital audio formats.
In the past, the traditional connection was analog signal or analog signal + digital signal transmission. And the new HDMI will be completely digital signal transmission.

How to use existing DVI cabling to ensure compatibility with the new HDMI interface:
Because HDMI is backward compatible with DVI, it can be directly connected, as long as there is a HDMI-DVI adapter to transfer it!
HDMI to DVI is backward compatible and there is no need to "Switch ". The "conversion Header" of DVI and HDMI is only the mechanical standard conversion of interfaces.

HDCP (high-speed broadband content protection) is a technology used by Intel to protect copyright of digital multimedia videos based on the Internet.

What is the difference between HDMI output and DVI to HDMI output?
When using a DVI video card to connect to an HDMI TV
Signal Source display DVI
The actual resolution is displayed in the signal format, for example, "1366*768 59hz"
There are few image options, and the color and sharpness options are blocked.
When you use an HDMI video card to connect to an HDMI TV
Signal Source display HDMI
The signal format does not show the actual resolution, but displays "720p", "1080i", or "1080p ". When the resolution of the video card is 1280 × 720 or lower, it is displayed as 720 p. When the resolution exceeds 1280 × 720, it is displayed as I/P.
The image options are rich, and the saturation, color intensity, and sharpness can be adjusted.

The video signal output by the DVI video card is RGB, and the signal encoding method output by the HDMI video card is YCbCr. The actual display results are also different.
The HDMI signal must be displayed point-to-point. The resolution of the TV (HDMI Interface) should be limited to 1280x720 or 1920x1080.
In contrast, the implementation of DVI graphics card point-to-point is not so harsh. That is to say, when connected to HDMI, the TV cannot be point-to-point, with black borders or excessive scanning.

DVI = HDMI? How can LCD TVs achieve point-to-point
LCD TVs are becoming increasingly popular. Recently, "point-to-point", "DVI to HDMI", and so on are increasingly seen.
After DVI is switched to HDMI, all problems cannot be displayed Point to Point. 1366x768 is the most common problem.
Is DVI like HDMI?
Why are some LCD TVs able to display normally, and some of them cannot display normally at a resolution of 1366X768?
Why frequent scans of DVI to HDMI input LCD TV display signals?

LCD TVs are video monitors. TV videos are dominated by (YCbCr) (chromatic aberration) signals, and the flushing rate is fixed at 60Hz. The signals used by computers and TV video signals are two different formats, which look very similar. One (rgbhv) and one (YCbCr) have many differences in usage.

First of all, starting from the computer graphics card DVI, most of today's graphics cards are DVI interfaces that mainly transmit (rgbhv) signals, (in fact, DVI can also be transferred (YCbCr) in addition to the transfer (rgbhv) signal) the essence depends on the source message number). Currently, all 1366x768 users use DVI output (rgbhv ).
While the HDMI interface that transmits signals from the DVI interface of the PC graphics card to the TV is known to be a digital (rgbhv), whether it is a DVI to HDMI connector, or the cable of one DVI head and one HDMI head is used for conversion. There is no line conversion except for the switch connector. The HDMI interface signal of the TV is still a DVI (rgbhv) signal.
The Design of HDMI is a new-generation interface generated by the combination of digital video (YCbCr) signals and audio. It can also be backward compatible with the (rgbhv) signals in DVI, of course there is no problem with the transfer.
However, LCD TVs are video monitors. The functional design is based on video (YCbCr). You can use the DVI interface of the HTPC graphics card to output (rgbhv) signals to the HDMI of the LCD TV. How to separate the two signals rgbhv/YCbCr after the interface receives the signal, or whether the two signals rgbhv/YCbCr can be switched at the same time in the Display Design circuit is critical.

Definition of HD and Full HD:
The standard of HD is that there are 1280 pixels in the horizontal direction, and 720 pixels in the vertical direction, that is, the 16-9 wide screen (1280: 720) that people often hear ), the screen resolution is 1280x720, which is the total number of images displayed on the entire screen.
In fact, Full HD doubles the number of pixels in the same area as HD images, that is, it can reach a resolution of X.