HDMI 2.0 released: 18Gbps of bandwidth allowing for 4K @ 60 fps, 32 audio channels

HDMI 2.0 released: 18Gbps of bandwidth allowing for 4K @ 60 fps, 32 audio channels

Kicking off the IFA consumer electronics show in Berlin, the HDMI Forum has released HDMI 2.0. HDMI 2.0 introduces support for 4K (2160p) at 50 and 60 FPS, 3D playback at 4K resolution, up to 32 audio channels (up from a paltry eight), and some interesting features such as “dynamic auto lip-sync” and the ability to deliver dual video streams to multiple users on the same screen. The max throughput of HDMI 2.0 is a beefy 18Gbps (up from 10Gbps), and you’ll be glad to hear that your stupidly expensive HDMI cable will continue to work with the new spec.

HDMI 2.0 is the first major update to the HDMI specification since version 1.4, which was released way back in 2009. 1.4a and 1.4b were released in 2010 and 2011 respectively, but they mostly focused on support for 3D — which, as we now know, is dead. HDMI 2.0, you’ll be glad to hear, shifts the focus back towards what the interface was originally designed to do: transfer high-definition multimedia content. To this end, the main change in HDMI 2.0 is improving the per-channel bandwidth from 3.4Gbps to 6Gbps, allowing for higher-resolution audio and video to be transferred. (See: Xbox One and PS4: Analyzing their support for 4K video and gaming.)

The HDMI spec calls for three discrete channels, which are primarily used to carry three different kinds of data/signal: The DDC (display data channel) negotiates which audio/video formats are supported by the receiver, and is used for HDCP (content protection DRM); TMDS (transition minimized differential signaling) carries the actual audiovisual data; and CEC (consumer electronics control) is a channel that allows the user to control HDMI-connected devices via a universal remote, or alternatively allows HDMI devices to control the TV/other HDMI devices. (For example, Google Chromecast uses the CEC command One Touch Play to automatically switch to the Chromecast when it begins playback).

As far as I can tell, all three channels can be used for audiovisual data, for a combined total of 18Gbps — but this only helps if you want to display three separate images. I don’t think you can combine all three channels to create a single 18Gbps, ultra-high-resolution feed. 6Gbps is enough to carry 4K video at 60 fps, or 3D 4K at 30 fps, along with 32 audio channels, and that seems to be the limit of the HDMI 2.0 spec. The DDC and CEC channels don’t require anywhere near 6Gbps (more like Kbps and Mbps), so most of the remaining 12Gbps will go to waste — unless you use HDMI 2.0′s new “dual video streams” function, which presumably uses two TMDS channels to display two video feeds on a single display. (Or maybe it just halves the main TMDS channel — we’ll probably have to wait a few more months for the spec’s exact details to become public.)

HDMI 2.0 also introduces support for the 21:9 aspect ratio, up to 1536KHz audio sampling, and “dynamic synchronization of video and audio streams.” We’re not entirely sure what the last one means, but the press release suggests that it will help with lip syncing.

HDMI 2.0 uses the same connector and cables as HDMI 1.4, but there’s no easy way to upgrade HDMI 1.4 devices to 2.0. The HDMI Forum notes that it’s possible for manufacturers to provide a firmware and/or hardware upgrade to enable HDMI 2.0, and we presume that Panasonic, LG, Sharp, and anyone else who has already released a 4K display is looking at providing such an update, primarily to enable 4K @ 50 and 60 fps. We expect the first HDMI 2.0 devices to be shown off at IFA over the next week, and they should begin to hit the market in the next few months.