What's New in HDMI 2.1 Version - VNZANE

HDMI Specification 2.1 supports end-to-end 8K/4K resolutions and higher refresh rate solutions with a single upgraded cable for seamless integration with the HDMI eco-system.

8K delivers a super-immersive viewing experience with 2x the horizontal and vertical resolution of 4K, and 4 times as many pixels; and combined with 60Hz refresh rate enables smooth and sharp viewing of content with high-speed action. 4K@120Hz enables ultra-fast motion UHD images to be crisp and razor sharp; and sports, action movies, high-performance gaming and VR benefit significantly.

In addition to 4K and 8K, a range of other resolutions are supported including 5K and 10K for commercial AV, industrial and specialty usages. Also supported are the latest color spaces such as BT.2020 with 10 or more bits per color and at higher frame rates.

The HDMI 2.1 Specification supports multiple static and dynamic HDR solutions. HDR enhances video images with an extended dark to bright contrast range for deeper blacks and brighter whites, greater detail in both the dark and bright parts in the same image, and greater detail within an extended color space.

Dynamic HDR enables a noticeable progression in overall video image quality from SDR to static HDR, and now static HDR to dynamic HDR. Dynamic HDR support ensures every moment of a video is displayed at its ideal values for depth, detail, brightness, contrast, and wider color gamuts—on a scene-by-scene or even a frame-by-frame basis. HDR-enhanced content is available for movies, videos, TV shows, video and PC games and VR.

HDMI 2.1 features Enhanced Audio Return Channel (eARC) which is an advancement over the previous Audio Return Channel (ARC). eARC simplifies connectivity and provides greater ease of use for multiple components discovery and audio optimization. It supports the latest high-bitrate audio formats up to192kHz, 24-bit, and uncompressed 5.1 and 7.1, and 32-channel uncompressed audio. It also supports DTS-HD Master Audio™, DTS:X®, Dolby® TrueHD, Dolby Atmos®. Now it’s easier than ever to experience movie theater quality sound in a living room for an immersive multi-dimensional experience and enhanced audio detail and depth.

eARC enables the audio to a TV that originates from cable, satellite, streaming or source devices to be sent to an AVR or sound bar through a single HDMI cable. This ensures the simplicity of connectivity and that the original audio can be experienced.

• Variable Refresh Rate (VRR) reduces or eliminates lag, stutter and frame tearing for more fluid and better detailed gameplay.

• Auto Low Latency Mode (ALLM) allows the ideal latency setting to automatically be set allowing for smooth, lag-free and uninterrupted viewing and interactivity.

• Quick Media Switching (QMS) for movies and video eliminates the delay that can result in blank screens before content is displayed.

• Quick Frame Transport (QFT) reduces latency for smoother no-lag gaming, and real-time interactive virtual reality.

One of the highlights from the HDMI 2.1 specification’s multiple gaming and media features is Variable Refresh Rate. VRR reduces or eliminates lag, judder and frame tearing for more fluid and better detailed gameplay. VRR enables a gaming source such as a console or computer to deliver video frames as fast as it can, which in many cases is slower than the normal static refresh rate.

Graphics processors require different absolute periods to render each frame, and this time is dependent upon the complexity of the scene, the horsepower of the GPU, the resolution selected and the frame rate. When the GPU is taxed by the other three factors and does not finish rendering the next frame by the time it needs to be displayed, the source must either repeat the current frame or display the partially-rendered next frame, which causes judder and tearing.

By waiting until the next frame is ready to transport it, a smoother gaming experience can be provided to the user.

Auto Low Latency Mode enables the ideal latency setting to automatically be set allowing for smooth, lag-free and uninterrupted viewing and interactivity. In many cases this is referred to as game mode, and it usually has to be set manually which involves going through menus and settings and then switching back again for normal viewing.

ALLM lets a game console, PC or other device send a signal to the display which will cause it to automatically switch to a low-latency, low-lag mode for gaming. This could benefit other uses, such as karaoke and video conferencing too.

But a low latency setting may not be ideal for other types of viewing since some processing features on a TV may be stopped in order to reduce latency. So with ALLM when the source no longer requires this mode—for example, when switching to a movie stream—the source disables the signal and the display reverts back to its previous mode for optimal picture.

HDMI 2.1 features Quick Media Switching for movies and video which eliminates the delay that can result in blank screens before content is displayed. QMS uses the VRR mechanism to eliminate the blackout period when all devices in the HDMI connection chain change video modes. As long as the resolution remains the same and only the frame rate changes, QMS will smoothly switch between frame rates.

For example, when looking at trailers from a streaming service, some may be in 24Hz, 50Hz, or 60Hz. Every time a trailer with a different frame rate is selected, the entire system must change its clocking and re-sync, causing an A/V blackout (a “bonk”). Knowing that a change-of-video mode causes bonks, streaming services may compensate and add a built-in delay so that users don’t miss the first part of the trailer. Or they may output everything at the same frame rate which requires either the streaming service to provide single-frequency streams or the streaming box to perform the conversion.

QMS eliminates bonks by using the VRR mechanism to change frame rates, allowing rapid, smooth changes from a nominal 60Hz rate to any media rate below it (down to 24Hz). The viewer never sees blank screens and gets a seamless experience.