HDMI 1.4 Delivers Ethernet and Upstream Audio Over 1 Cable

HDMI 1.4 delivers two big features that earlier specs lacked: data and bi-directional audio. The new capabilities could eliminate the need for extra Ethernet and audio cables -- a single HDMI can do the trick.

Two-Way Data

With transfer speeds of up to 100 Mbps, the HDMI Ethernet Channel (HEC) will enable countless IP-based applications that previously required a dedicated Cat 5 cable connected to the home network.

Now, instead of running Ethernet to every component in an A/V stack, only one device needs to be connected to the network via Cat 5+. The rest of the devices get their IP connectivity over HDMI.

Internet connection sharing is one of the "clear" applications that will come out of the new feature set, according to Steve Venuti, president of HDMI Licensing LLC. "But I honestly think we don't know all of the applications people will come up with."

The HDMI group itself is not creating applications for the Ethernet channel. The functionality will come from UPnP and other providers, Venuti says. "This is pure pipe."

Research firm Instat reports that 24% of all consumer electronic devices will require Ethernet in 2009. All game consoles and digital media adapters will be networked in 2009, along with 80% of Blu-ray devices and 72% of PVR/DVRs, Instat estimates.

Assuming all of those devices are also connected via HDMI to other components, consumers could eliminate that many Cat 5 cables from the clutter.


HDMI without HDMI Ethernet Channel (left); HDMI 1.4 with HEC

HEC requires much more than a firmware update or other quick fix. The solution will need to be implemented in HDMI cables as well as the components.

The architecture of the cable changes little. "The difference in cable is not visible to the naked eye," Venuti says. "but you will need a cable that says 'high-speed with Ethernet.'"

HDMI developers have always reserved extra pins for data, he explains; they're just now getting around to implementing.

Upgrading devices to HDMI 1.4 will take some effort. Manufacturers will need a new chip and possibly some kind of Ethernet switching mechanism.

The group anticipates that some TV and settop box manufacturers may "go all out," Venuti says, possibly with built-in processors and software to stream content to and from other sources.

Two-Way Audio

As long as you're losing an Ethernet cable, why not drop the audio cable as well?

HDMI 1.4 provides for an audio return channel (ARC) that enables upstream audio over HDMI.

"What if you have a built-in tuner at the TV?" Venuti says. "How would you get the audio back to the receiver? You would need a separate cable like an S/PDIF."

Not anymore. HDMI 1.4 can handle the audio both upstream and downstream … along with HD video and two-way data.


HDMI without audio return channel (left); HDMI 1.4 with ARC.

HDMI 1.4 Roll-out

Venuti anticipates that the roll-out of HDMI 1.4 will mirror that of 1.3 in terms of adoption rates among A/V vendors.

The spec will be available for download by the end of June and and we'll probably see some compatible products in time for CES in January 2010.

In addition to Ethernet and upstream audio, HDMI 1.4 supports:

• HD resolutions up to 4096x2160
• 3D up to 1080p definition
• "Real-Time Content Recognition" (adjusting video settings automatically based on connected device)
• Additional color spaces, especially for digital still cameras
• Micro connectors
• Automotive connectors

(Read the HDMI 1.4 press release.)

What a development! HDMI 1.3 didn't bring anything discernible to the everyday TV viewer.

"1.3 was more about bandwidth, more of the same," says Venuti. "This, I think, is a whole new paradigm. It gives us a whole new ability to do things we've never done before.