HDMI is the most popular A/V interface currently dominating the A/V market, covering almost all fields such as TV, monitor, computer, projector and splicing screen. So what are the improvements to HDMI 2.1 compared to the current mainstream HDMI 2.0?
As far as the market is concerned, 4K (3840 × 2160) resolution is already in vogue, but 8K (7680 × 4320) resolution is on the way, not to mention 10K resolution.
HDMI 2.1 is the latest version to the current HDMI specification, with advanced features of the HDMI ecosystem. It supports a range of higher video resolutions and refresh rates, as well as using the new 48G HDMI cable to increase bandwidth.
The increase in bandwidth is the most significant improvement brought about by HDMI 2.1. The bandwidth of HDMI 2.0 is 18 Gbps, while the bandwidth of HDMI 2.1 is an impressive 48 Gbps. The dramatic increase in bandwidth makes it possible for a number of other features supported by HDMI 2.1, such as 8K and 10K video resolution, 4K video resolution with a refresh rate of 240Hz, and so on. To enjoy the benefits of HDMI 2.1, users need new cables—it should be marked “Ultra High Speed HDMI” (very High Speed HDMI)—which isn't too expensive compared to the new features offered. HDMI 2.1 also supports VESA’s “display stream compression” to further boost bandwidth.
8K and 10K resolution may be a long way off, but the HDMI 2.1 standard also enhances 4K resolution output, and has now been upgraded to support the transmission of 4K@120Hz content. In addition to resolution, which has the greatest impact on image quality, another significant difference is the improvement of high dynamic range(HDR), and the new HDMI 2.1 standard now supports Dynamic HDR.
It would be a pity if not to have seen the real HDR picture. It improves color and higher contrast, and improves image quality to a much higher resulution than the original, which rose from 1080P to 2160P. Having watched several films in support of the dolby vision, the TechHive’s building administritor was quite unsatisfied to his regular television. Honestly, if you can choose between a 4K resolution picture that doesn't support HDR and a dolby 1080p resolution picture, most users will choose the latter. After all, the picture quality of the latter is much better.
In addition to these new features, HDMI 2.1 also adds several technologies that can enhance refresh rate for video, movies, and games, ensuring users to enjoy fluent and blockless image when using high resolution. For example, the variable refresh rate (VRR) used in the game can reduce the delay, blocking and tearing phenomenon of the image, making the player enjoy more fluent game. There is also the “quick media switch (QMS)” for video and movies, which eliminates the delay that leads to a white screen before content is displayed. While “rapid frame transmission (QFT)” is aimed at VR (virtual reality), which greatly reduces delay and makes the experience of real-time interaction better. There is also “automatic low latency mode (ALLM)”, under which the optimal delay can be set automatically.
The audio improvements in HDMI 2.1 come from higher bandwidth. Bandwidth has increased from 1Mbps of HDMI 2.0 to 37 Mbps, which enables it to support high-bandwidth, object-based surround coding—such as Dolby Atmos and DTS:X.
It should also be noted that the transmission of 192kHz audio is a huge waste of bandwidth, since it transmits audio frequencies that do not exist in the audio source, and even if those frequencies exist, the user cannot hear them. The idea that higher data means better sound quality is ingrained in the market. Under one occasion, this is almost true. Compared with16-bit audio, 24-bit audio reduces background noise so that even in ultra-quiet environments, people with very good hearing cannot detect it.
Anyway, surround stereo enthusiasts will find that HDMI 2.1 supports better surround sound. It should be noted that eARC requires the use of HDMI cables which enable Ethernet.
The upgrade to the HDMI 2.1 specification is theoretical, and it will take time for the average consumer to enjoy the benefits. And there is currently no chip to support HDMI 2.1, which means that consumer electronics that support HDMI 2.1 won’t be available until late 2018 or early 2019.
HDMI 2.1 will first be used in high-end graphics cards for gamers, as well as in medical, industrial and scientific imaging systems. Since the Tokyo 2020 Olympics will be broadcasted with 8K technology, it is not surprising that a small number of 8K TVs are already on the market.