School Author: Misaruka
Domestic HDMI wire market and confusion, often encountered compatibility, such as the most common 1.4 and 1.3 incompatible, 1.4 and 2.0 are incompatible. Seeing this may say that this is a chaotic, clear version of HDMI after CAT2, and the line is common.
In fact, this sentence is not accurate, in detail below.
HDMI complete wire includes two parts: interface and cable:
In terms of interface, the HDMI alliance defines 5 specifications of Type A / B / C / D / E, with the double-port B basic no manufacturers in doing (only one product is registered in the official website) does not use it, the remaining C and D-mouth is Mini HDMI and Micro HDMI. The former camera may be used, the latter is common in small mobile devices such as mobile phones (there are many small D than C), and the E-mouth is a car special port, which is 21.9mm long, and there is anti-falling outside. The barb is less. The most common on the market is A port, 13.9mm long, including TV, monitor, player, game host, etc., many household digital devices.
The cable part, the HDMI alliance divided into 9 categories, and also puts forward a certification process called Category. After the process is completed, according to the bandwidth value of the sample cable, divided into category1 / 2/3 three Different certification criteria, as follows:
Standard HDMI Cable
Standard HDMI Cable with Ethernet
Standard Automotive HDMI CABLE
High speed HDMI CABLE
High speed HDMI Cable with Ethernet
High speed Automotive HDMI CABLE
Premium High Speed HDMI CABLE
Premium High Speed HDMI Cable with Ethernet
The Ultra High Speed HDMI Cable
The start of Standard is CAT 1, with the bandwidth of less than 2.25Gbps; high speted is CAT2, not below 10.2Gbps (HDMI 1.3 introduction), and Ultra High Speed is CAT3, which is the latest HDMI2.1 standard match New cable bandwidth 48 Gbps. In addition to Cat3 and Premium High Speed, CAT1 and CAT2 certification, it corresponds to three, respectively, and the Normal Edition, the web version, and Automotive, the car version.
It should be noted that premium high speed is very special, the official did not explain it belonging to CAT2, but because Ultra High Speed is Cat3, then put it in 2 inside, or it can be said to be CAT2 super, bandwidth 18Gbps. The device has a yellow QR code sign through the apparatus, which is not previously available. From the HDMI Union official website, the online version of Premium seems to be used by the old version of the high speed blue mark, which can be found in the following model.
Seeing this here, how will it be a combination of 9 cables and 5 interfaces? Considering the difference between the interfaces, then 9 * 5 * 5 = 225 combinations will appear.
In fact, as mentioned earlier, the B port is substantially absent (HDMi official website only 1), and the car-loaded E port is very small (using A port), and the C port is replaced by the D mouth. It is a D-mouth in recent years, there is also a USB-C excessive trend (saving the valuable space of mobile devices). So, only 9 of the A ports is almost.
But you think so, don’t.
The HDMI Alliance continued to engage in, and raised a so-called HEAC (HEC + ARC) bus (BUS), simply, the above-mentioned Ethernet (100M Ethernet) and ARC (Audio Back). Ethernet and Arc are transmitted by using the opposite signal, and for actual products, these two functions exist. In other words, those online version of the “with ethernet” can also use ARC function. With this understanding, it is not only the CAT2 network version of the ARC, and the CAT1’s network version can also exist. If these products have to appear in the world, it is possible to further interfere with the user choice.
Fortunately, the current product is mainly based on Cat2 and Cat2 webmates, and the product of the Cat1 online version seems to be seen. Even the products marked with HEACs in the international market are also very few (except for the Japanese companies such as Bavaro), the Sony, one of the initiators, is also written by HEC and ARC.
The above mentioned CAT1, CAT2, premium, etc., based on bandwidth, then before purchasing the cable, we can also try the HDMI bandwidth required by our own equipment.
The simplest method is that the resolution X refresh X color depth, such as 60Hz 60 Hz, 8bit color depth:
1920 * 1080 * 60 * 10 * 3 (multiplication is divided into three channels due to RGB)
However, this data is incomplete because it is not 100% to transmit video data when TMDS-based HDMI transmission data, and signal data that does not contain video (such as Blanking Intervals) is required. As for how the specific TMDS is to do, it is necessary to see what time series standard in which it is used. The mainstream has a CVT-R2 standard and a CTA-861-G standard. The former is an integral part of EDID (Extended Display Identification Data)). The latter is E-EDID (formerly extension). Simply speaking, they are used to match the device compatible data by reading the built-in chip, and of course the timing information is also included. Interested in viewing standards, do not repeat them here.
CTA-861-G (predecessor EIA / CEA-861) is developed by CTA, all name consumer technology association, namely Ding Ding’s American Consumer Technology Association, the annual CES exhibition is hosted by it, member exceeds 2,200 companies.
CVT-R2 is developed by VESA, a CVT standard for a CRT display, and later introduced R2 versions of the LCD display, that is, the current CVT-R2. Relatively Almighty CTA, VESA is a small amount of more than 1/10 of the former.
These two standard timing methods have differentials, and the calculation of bandwidth is different (in general, CVT-R2 is small). The 861 of CTA is primarily used (including HDMI alliances), while VESA is mainly used in the display. Early Some graphics cards were used by TMDS (at that time, or DVI, ie HDMI’s predecessor), the graphics drive panel can even change it:
Exterior, not only the old yellow N card used the Silicone TMDS chip, ATI (now AMD) has also been purchased.
Since the 861 has a ready-made PDF, click on 861 (Although VESA is also free standard, you need to register).
According to the standards of the CTA 861, 1080p and 2160p corresponding to the 60 Hz refreshing are 280/45, 560/90, respectively, and the pixels of this portion are also incorporated into the original horizontal resolution, and 8bit is included inside the TMDS. 10bit conversion, so final:
(1920 + 280) * (1080 + 45) * 8 Bit * 60Hz * 10/8 * 3 = 4.455Gbps
(3840 + 560) * (2160 + 90) * 10bit * 60Hz * 10/8 * 3 = 22.27Gbps
Another is also a more common computational bandwidth method, first calculate the cost of the HDMI code 8bit to 10bit, such as the HDMI 2.0 18Gbps bandwidth is 18Gbps * 8bit / 10bit = 14.4Gbps
So, (3840 + 560) * (2160 + 90) * 10bit * 60Hz * 3 = 17.82Gbps
At first glance, it seems to meet 18Gbps, but there are 8bit to 10bit encoded conversion due to HDMI 2.1 below, actually only 14.4g bandwidth, has been discounted in advance, so it is still not satisfied with 4K60Hz RGB 444.
According to the above formula, the 4K60Hz of 8 bit444 calculates 14.256GBP, just satisfied with the 18 Gbps / 14.4 Gbps standard of 2.0, so if there is no HDR, it is also possible to reach RGB with 8bit. But Sony, etc., 4K Blu-rays, UHD BD standards, Blu-ray movies have almost all HDR, and 10bit is its must require, only other way out.
Solve in addition to the 2.1 version of the device, you can also switch to the YCBCR420 and 422 format (a sample compressed format, compressible volume) to save data, divide 2 and 1.5 of the above calculated bandwidth, which can be easily Meet the maximum bandwidth. Such as Sony’s PS4 Pro host, when it turns on 4K HDR, the 420 replaces RGB 444, which is because the HDMI 2.0 protocol bandwidth is insufficient.
The next place returned to the beginning, why said “Cat2 (ie HDMI 1.3, High Speed) has a problem (here, there is 2.1).
First, PREMIUMHIGH SPEED authentication and high speed are still different, although the latter now has many products to promote their own bandwidth of 18/14.4Gbps. The official explained that Premium will increase EMI (electromagnetic interference) while detecting bandwidth, avoiding other equipment due to HDMI problems (such as wireless speakers used by the home theater, etc.), and High Speed does not. After all, consumers are not ATC, and it is impossible to test it. The premium product that passes the official certification test is basically more expensive than the latter, and the former even has a product that is higher than the transfer efficiency of silver.
Second, the High Speed Standard Edition and Premium High Speed Standard Edition has no network characteristics, that is, there is no ARC, if you want to use ARC to return to other devices audio, then the network version is not acknowledged, and the standard version of the product cannot be purchased.
Finally, common domestic manufacturers do not press HDMI official certification standards, they have their own routines.
In the 7 found companies of the HDMI Alliance, there are currently two wires of Sony and Philips. As a founded member, the two or the comparative rules use the official standard to identify the product, the packaging position is labeled is Standard (CAT1) or high speed (cat2), or Premium High Speed. But even Philips, most products did not mention Arc, even those models labeled network certification, the product introduction map also has many mistakes, which is not uncommon to put other manufacturers.
Take a look at how other domestic manufacturers. Although the manufacturers have a total of 10,000 knives per year (the patent usage fee is counted as if the patented use fee is counted), it will not be able to indicate the CAT number or high speed and other certifications on the packaging. Up to just tell you the version number. In fact, in 2012, the HDMI alliance has banned to indicate the HDMI version on the package, but domestic manufacturers have their own ideas and did not follow up.
For example, these Jingdong sell a better explosion, although the same words are written on the product name, HDMI 2.0 and other words, but in fact, it is actually supported by the 18Gbps bandwidth of 2.0 to meet 4K60, you need to see its length. . However, this prompt, there is a very eye-catching place, the consumer is easy to ignore, you must recognize yourself before the order:
Since the same size, the same model is 5 meters away from 4k60, 5 meters outside.
Shengwei HDMI Line 2.0 version 4K digital HD line 3D video cable computer set-top box connection TV projector display data cable 1 meter HC-9010B18.9 yuan
Shanshi, the same model length supports 4K60, 3 meters outside the length of 3 meters.
Samzhe Super fine plated luxury version 2.0 HDMI digital HD line 5 meters support super clear 2k * 4K resolution 3D function SM-65052.9 yuan
The length does not attenuate the signal, and if you have too long, you will definitely not reach standard bandwidth to reduce standards. Some longer advanced wires will use programs such as power amplification to improve signals, and cost will increase much. But no matter what to say, this all makes a model too mess. Only one unrelated CCTV3 in the packaging of Shanshi, HDMI certification is also not mentioned.
In summary, you can’t just see the highspeed or indicate that 18Gbps bandwidth is bought. It is likely that it will meet 18Gbps due to length or authentication issues. It is also possible because it does not meet the ARC and cannot meet your audio return demand. .
So how should I buy, simply, I have to choose a certified product, followed by non-authentication, further subdivision according to my own needs,
Demand 4320P 100Hz, 2160P 120Hz, 2160P 60Hz RGB444, HDMI 2.1:
Individual manufacturers such as CLUB3D, Belkin have this specification, and there are few HDMI2.1 devices and wires, and they need to be paved in the market.
Demand 2160P 60Hz, HDMI 2.0, HDR, 3D, priority PremiumHigh Speed Certification:
Philips SWL6122A / 93
Philips (Philips) HDMI Line 2.0 version 4K HD line premium certified ARC 2K 165Hz refreshing eating chicken electricity display cable 1 meter SWL6122A / 9399 yuan
Philips SWL6122E / 93, multiple networks than 22A certification markers, may be the premium high speted hdmi cable with Ethernet that is mentioned above, if so, then support Arc
Philips HDMI Line 2.0 version 4K HD line premium certified eaten e-sports computer display projector HD cable 5 meters SWL612E / 93199 yuan
Demand 1080P 60Hz / 1080P120Hz / 1440P 60 Hz / 2160P 30Hz, 3D, preferred HIGH SPEED certified:
Sony’s High SpeedHDMI Cable with Ethernet, clear ARC support
Sony (SONY) HDMI high-definition line set top box TV computer 3D projector PS4 HD video cable speaker HDMI cable standard HDMI line 0.7 meters 68 yuan
The high refresh screen used by the game players, such as 1080p 144Hz, 180Hz or more, this generally display (TV is generally up to 120Hz, 861 is completely no corresponding standard), wire generally recommended DP, if not With HDMI, preferred high bandwidth, because the bandwidth of Cat2, high speed under 10bit is not 144 Hz 1080p, can only select HDMI 2.0, and 12Gbps bandwidth can be selected. If it is 1440p 240Hz or higher refresh 8bit / 10bit monitor, 2.0 can’t save you, only DP1.3 or HDMI 2.1 (existing display products should not have).
Apperates again. You need to play SACD or Dolby TrueHD, DTS Master HD, and DTS Master HD, after the non-destructive format, as long as the player can decode, the wire is no problem, but it is necessary to pay attention to the maximum resolution of the player, and whether there is also ARC and other needs (audio often appear at the same time, HDMI official website said that audio is not rigorous with the audio).
Finally, if you must choose a domestic model, but just there is no such certification, then you must first look at the HDMi version of the corresponding length; secondly to communicate with the customer service as 18Gbps bandwidth, ARC, 3D these characteristics support or not; It is also necessary to ensure that you don’t buy a fake product on the stall. These products not only reach the nominal bandwidth, but also because of pin design issues, it is likely to burn the port during the insertion process.