The Truth Behind HDMI 1.4a

Way back on May 28, 2009, HDMI Licensing released the HDMI 1.4 spec. There were a few things that were exciting about HDMI 1.4. For home theater there was an increase in the maximum resolution to 4K × 2K (3840×2160p at 24Hz/25Hz/30Hz and 4096×2160p at 24Hz), an HDMI Ethernet Channel which allows for a 100 Mb/s Ethernet connection between two HDMI connected devices, and an Audio Return Channel. Most importantly, we were led to believe, was the inclusion of support for 3D. In those pre-Avatar times, this was perceived as a bit premature. Of course, we now know that it wasn't, as only recently HDMI 1.4 receivers are hitting the market.

But wait, it's less than a year later (March 4, 2010) and here comes HDMI 1.4a.

We're not going to say that HDMI 1.4a took us by surprise... OK it did a little. Practically before HDMI 1.4 products hit the shelves, the 1.4a spec was released. The big change from 1.4 was that 1.4a mandated two new 3D formats for broadcast on top of the game and Blu-ray formats. HDMI 1.4 required that 3D displays support the frame packing 3D format at either 720p50 and 1080p24 or 720p60 and 1080p24. HDMI 1.4a added side-by-side horizontal at either 1080i50 or 1080i60 and top-and-bottom at either 720p50 and 1080p24 or 720p60 and 1080p24. While some manufacturers would like you to believe that only their receivers/products sporting HDMI 1.4a will handle these formats, is it true?

We'll give you a big fat 'Maybe'.

Twice reported that HDMI stated that manufactures have to confirm for themselves that their devices will support the new mandated formats. This means that they'll have to test their recently released devices with content that hasn't been created yet. It's either that or upgrade to HDMI 1.4a. This is harder for some than others.

For sources, they only need to support one of the mandated 3D formats (which makes sense). Receivers need to be able to pass all four and displays need to be able to accept and display all four. According to Steve Venuti, President of HDMI Licensing, HDMI 1.4 equipped AVRs (receivers) should be able to pass all four formats as the new broadcast formats are essentially the same as 2D video. Of course, he put the onus on the manufacturers to make sure that his statement was true for their specific devices.

Displays are in a completely different boat. Consumers will want to pay close attention to the supported 3D formats on any new 3D display they are thinking of purchasing. If the device has HDMI 1.4, you know it can support the Blu-ray and game 3D formats. The formats they'll want to look for are the broadcast ones - Side-by-Side Horizontal (1080i at 50 or 59.94/60Hz) and Top-and-Bottom (720p at 50 or 59.94/60Hz as well as 1080p at 23.97/24Hz).

The question in many consumer's minds is whether or not their receiver can pass the new formats or be upgraded via firmware to be HDMI 1.4a compatible. The answer is - yes. Depending on the initial implementation of the HDMI 1.4 spec, it may be out of the box ready or require a firmware update. In fact, Harman Kardon is already planning to upgrade three of their 1.3a receiver to 1.4a. Since they are saying that their receivers will be upgraded to "HDMI v.1.4a with 3D," we assume that means you'll get all the additional features as well (not just 3D). We're not sure how this is possible since HDMI initially claimed that you needed a different chipset for 1.4. If so, however, you'll need HDMI 1.4 cables to take advantage of the Ethernet Channel feature (the Audio Return Channel is more or less supported with current generation cables). Other HDMI 1.3a receiver owners shouldn't hold their breath for upgrades, however, as no other manufacturer has announced any similar plans.

Conclusion

While you're going to see more and more HDMI 1.4a devices released in coming months, those with HDMI 1.4 receivers shouldn't be too concerned. Chances are, your 1.4 receiver will either work with the new HDMI 1.4a 3D formats out of the box or can, in theory, receive some sort of firmware upgrade. Whether it will or not remains up to the manufacturer. The real concern should be for people with new 3D displays. They are going to want to make sure that their display will support all four of the 3D formats in order to take advantage of, in particular, any broadcast 3D possibilities that may come up in the near future.