HDMI
Televisions, game consoles, monitors, players, set-top boxes... HDMI has taken over as the most widely used modern connector for transmitting audio and video signals in the home.
About HDMI
HDMI connectors are now found on almost every device that can display digital content. At first glance, it looks like any other cable, but not only can it transmit both image and sound, it can do so in near-perfect quality. That's because these cables transmit a lossless digital signal.
Connectors
HDMI has four different connectors:
Type A – the standard 19-pin connector found on televisions, consoles, and computers
Type B – a virtually unused 29-pin connector that you are unlikely to encounter in everyday life
Type C-mini – a 19-pin connector, the smaller brother of Type A, used in portable devices such as players and cameras
Type D-micro – a connector similar in appearance to microUSB, but Type D is narrower and taller. It still has 19 pins. It is mainly used in digital cameras and some tablets.
Type E – a connector used mainly in the automotive industry.
Version
Versions are a little more complicated. According to the HDMI Forum, it seems that you can refer to the HDMI version in a numerical series (e.g., 2.1, 1.4, etc.), but only if it is an HDMI specification, not if it is the cable itself—the cable must be labeled with the given nomenclature (e.g., PREMIUM HDMI CABLE). Since these names can seem lengthy and sometimes counterintuitive, it is better to refer to the maximum resolution and frequency that the cable can transmit (e.g., 4K2K@60Hz).
Table (standard color depth 8bpc)
| Standard version name | Cable version name | Max resolution and frequency | Highest max resolution and frequency with compression | Note |
|---|---|---|---|---|
| HDMI 1.0 | 1080p@60Hz | |||
| HDMI 1.1 | 1080p@60Hz | |||
| HDMI 1.2 | 1440p@30Hz / 1080p@60Hz | |||
| HDMI 1.3 | Standard HDMI® Cable | 4K@30Hz / 1440p@75Hz / 1080p@144Hz | 5K@30Hz | |
| Standard HDMI® Cable with Ethernet | 4K@30Hz / 1440p@75Hz / 1080p@144Hz | 5K@30Hz | Same as Standard HDMI® Cable, but has a special channel for Ethernet signal transmission | |
| HDMI 1.4 | High Speed HDMI® Cable | 4K@30Hz / 1440p@75Hz / 1080p@144Hz | 5K@30Hz | |
| High Speed HDMI® Cable with Ethernet | 4K@30Hz / 1440p@75Hz / 1080p@144Hz | 5K@30Hz | Same as High Speed HDMI® Cable, but has a special channel for Ethernet signal transmission | |
| HDMI 2.0 | Premium High Speed HDMI® Cable | 4K@60Hz / 1440p@144Hz / 1080p@240Hz | 8K@30Hz | |
| Premium High Speed HDMI® Cable with Ethernet | 4K@60Hz / 1440p@144Hz / 1080p@240Hz | 8K@30Hz | Same as Premium High Speed HDMI® Cable, but has a special channel for Ethernet signal transmission | |
| HDMI 2.1 | The Ultra High Speed HDMI® Cable | 8K@30Hz / 4K@144Hz / 1440p@240Hz | 8K@120Hz |
Higher color depths require higher cable bandwidth. For example, with a color depth of 10bpc, bandwidth utilization increases by up to 25%. This can reduce the maximum resolution along with the maximum refresh rate.
Compression
Compression allows us to achieve higher resolution, frequency, or even increase the color volume to 10 bits, but at the expense of image sharpness. This is usually not a problem with TVs (unless they are used as PC monitors or for reading text), but with personal computer monitors, compression can cause significant problems with text readability.
Versus DisplayPort
HDMI enjoys great popularity, similar to that experienced by VGA, for example, and for good reason—it offers everything a mere mortal could want and continues to evolve. However, it has one very dangerous rival—DisplayPort. Although it cannot boast the same popularity, it can boast better specifications and better user-friendliness, and most importantly, it is an open standard, which means that it does not require any license for implementation, but at the same time, it does not require any strict certification to check for proper implementation, which can be a double-edged sword, especially for the customer. HDMI also has slightly higher reliability at lengths over 2 meters, although VESA (the developer of the DisplayPort standard) guarantees reliability up to 15 meters.
One of the main differences between HDMI and DP is in their communication capabilities between the source and the display unit.
HDMI is designed for convenient use of multiple devices connected to a single display unit (most often a TV). If all devices are connected via HDMI and support HDMI-CEC technology, they can be controlled with a single remote control (which may be a TV remote control). So, for example, we can control both the TV and the game console or set-top box with this single TV remote control. This is because these devices communicate with each other through this cable. In addition, thanks to ARC or eARC technology, you will not need an additional cable to connect the sound between the home theater and the TV when connecting your home theater to the TV. HDMI takes care of this data itself.
DisplayPort does have CEC support capabilities, but few implement this feature. After all, HDMI is better suited for this and is more widely used for these purposes.
DisplayPort, on the other hand, is designed to transmit a signal from one device to several display units via a single DisplayPort input on a PC. Simply connect the PC to the monitor and then connect this monitor to another monitor using another DisplayPort cable, and so on. Just be careful, because with each connected monitor, the maximum possible resolution and frequency that this standard can handle decreases. HDMI does not offer this feature at all.
Although it seems that these two standards are perfect for huge commercial rivalry, they coexist in relative peace and try to assert themselves in their own territories, where they already dominate. HDMI still remains mainly a thing for ordinary households (TVs, cameras, game consoles), while DisplayPort is used in IT (gaming and office PCs).
USB may pose a greater concern with its new 4.0 version, which is dangerously close to HDMI specifications.
