Amidst the hubbub of 3D this and 3D that at last week's Consumer Electronics Show (CES) in Las Vegas, the technical requirements of 3D HDTV and Blu-ray 3D became a major topic for discussion.
One of the primary questions was this: Will current HDMI hardware and cables be sufficient to accommodate the increased bandwidth requirements of full HD 1080p 3D? Or will consumers have to plunk down additional dough for all-new cables, A/V receivers and switching devices that are compliant with the recently-finalized HDMI v1.4 specification? Complicating things further was the fact that answers seemed to vary depending on who you talked to.
With DIRECTV's announcement that 3D satellite channels will be appearing on the listings guide in a matter of months - and will work with customers' existing set-top boxes - and with every major CE manufacturer showing off a new 3D Blu-ray Disc player, now seems like a good time to get to the bottom of the HDMI question. If you're already saving your pennies with the goal of bringing your home theater into the third dimension, it would be helpful if you knew just how much coin you need to stash under the mattress.
Since Blu-ray 3D is by far the highest-quality 3D content consumers are apt to see at home, it makes sense to focus our attention there. The assumption being, whatever will work for Blu-ray 3D will also work for DIRECTV 3D, ESPN-3D, and whoever else decides to venture beyond two dimensions.
As mentioned earlier, virtually all of the CE industry's heaviest hitters had a Blu-ray 3D player on display at CES. One of them, Panasonic's DMP-BDT350, features dual HDMI outputs: one for HDMI v1.3 and one for HDMI v1.4. Speaking with a Panasonic representative about this, I was told that consumers using non-3D HDTV displays could use the HDMI v1.3 output and they can use the player much as they do today with their current DVD or Blu-ray Disc player. When they eventually upgrade their display to 3D, they can simply switch over to using the HDMI v1.4 output. This would seem to imply that HDMI v1.4 is a requirement for Blu-ray 3D delivery.
However, also at CES, Sony made the announcement that in addition to its upcoming 3D Blu-ray Disc player (the BDP-S770), they would soon be releasing a firmware update for the Playstation 3 (PS3) which would make the gaming console Blu-ray 3D-compatible. The PS3 is not a new device and its onboard HDMI hardware is only compliant with the HDMI v1.3a specification. So if the PS3 can output 3D Blu-ray content, that should tell us that HDMI v1.4 is in fact NOT required. Right? Confused yet?
"You've beaten my giant, which means you're exceptionally strong, so you could've put the poison in your own goblet, trusting on your strength to save you, so I can clearly not choose the wine in front of you. But, you've also bested my Spaniard, which means you must have studied, and in studying you must have learned that man is mortal, so you would have put the poison as far from yourself as possible, so I can clearly not choose the wine in front of me..."
-The Princess Bride
Inconceivable, I know. Before going any further, allow me to shed some light on the Panasonic's dual HDMI outputs. The primary reason for this is to allow a direct HDMI v1.4 connection between your Blu-ray 3D player and your 3D HDTV, with the secondary HDMI output can be used to deliver just the digital audio stream to your A/V receiver for soundtrack decoding. Since all current A/V receivers are only HDMI v1.3-compatible, this seems like a smart way to do things, at least until everything migrates to HDMI v1.4.
On a related note, it's worth pointing out that HDMI v1.4 includes a new command protocol for 3D displays (new extensions to the EDID protocol) that reportedly help a compatible display to configure itself when a 3D signal is detected -- in fact they allow the display device to tell the source component that it's OK to send over a 3D signal. Since this feature is not available with HDMI v1.3, it's assumed that the setup process there may require additional manual intervention on the PS3 once the promised Blu-ray 3D upgrade becomes available.
BPBS: Do consumers need HDMI v1.4 end-to-end in order to take full advantage of Blu-ray 3D?
AP: It's not required to use 1.4 as long as everything in the signal path is capable of handling the 3D payload. This means, for example, that HDMI 1.3a can be used if all components, including cables and HDMI switching devices (such as A/V receivers) are "High Speed HDMI." It's important to check with the manufacturer of any switching device to see if it complies with High Speed data rates. If not, then the 3D player's video output should be connected to the 3D display directly using High Speed HDMI cables, with audio connected to the A/V receiver via analog or other digital outputs.
[update (July, 2010): It turns out that Mr. Parsons was a little optimistic about the capabilities of an HDMI 1.3 receiver to pass along the Blu-ray 3D video stream. Because HDMI 1.3 receivers cannot pass through the new 3D-specific EDID parameters, it is not possible to pass a Blu-ray 3D stream through one of these receivers and on to a display. Some of the first generation players such as Panasonic's DMP-BDT350 and Samsung's BD-C7900 feature two HDMI outputs for just this reason - the HDMI 1.4/3D video output is connected to the TV while the audio is passed via a secondary HDMI output to a non 3D-ready receiver.]
(For more information on "High Speed HDMI" and the HDMI Licensing organization's HDMI classifications, check out HDMI.org.)
BPBS: In the BDA's press release surrounding Blu-ray 3D, it states that "...the specification supports playback of 2D discs in forthcoming 3D players and can enable 2D playback of Blu-ray 3D discs on the large installed base of Blu-ray Disc players currently in homes around the world." It also states that "...the Multiview Video Coding (MVC) codec... can provide full 1080p resolution backward compatibility with current 2D Blu-ray Disc players."
Does this mean that 2D and 3D versions will co-exist on the same disc? Are separate 2D and 3D discs bundled within one SKU a possibility? Or is it only one video encode that we're talking about, one that can simply be rendered in either 2D or 3D depending on the type of player? Bottom line: is it conceivable that we'll see 3D Blu-ray titles that only provide a 3D experience, where 2D playback is "sold separately?"
AP: The Blu-ray 3D specification provides a way to author 3D discs such that the left eye represents the 2D version of a film, with the right eye containing additional information for the 3D effect on compatible displays. This means that a 2D-only player can detect the left eye portion of the data stream on such discs as if they are traditional 2D programs. On discs that are authored this way, the net result is that a 3D disc can accommodate both 2D and 3D players with the same data stream. It is not a requirement that discs be mastered this way, but it is an option for the studios to do this in order to provide backwards compatibility.
[Update (July, 2010): Andy e-mailed us to clarify that studios that choose to author Blu-ray 3D titles without 2D compatibility must label said disc clearly as "3D only" so as to alert consumers.]
As to the question of multiple discs and 2D being sold separately, that's more of a packaging and marketing issue, and the BDA doesn't get involved with that side of things.
BPBS: OK, so would a Blu-ray 3D player require 3D playback of a 3D Blu-ray title, or can consumers opt for 2D playback of a 3D title, even though they may have a 3D-compatible HDTV and a 3D Blu-ray player? For example, let's say a consumer upgrades to 3D, but isn't impressed with the 3D effect on one of his 3D Blu-ray titles. Can he choose to watch the 2D version of that title, even if he's using 3D hardware?
AP: As far as I know, there is no requirement for a 3D player to provide a 2D playback mode with 3D titles. It would certainly not be easy to do so if the disc were authored for 3D playback only. This scenario might happen with films that cannot provide a 2D equivalent version in the left eye portion due to the way they were originally produced to create the 3D effect. But for titles authored with both 2D and 3D playback modes, it would certainly seem like a nice idea for players to offer a selection capability for those who may not wish to (or are unable to) view a film in 3D at any given time.
Like anything else in the CE industry, penetration and roll out of Blu-ray 3D and HDMI v1.4 is going to take time. It's not going to happen overnight and manufacturers realize that few consumers are going to be willing to upgrade their entire video chain all at once. That said, Onkyo's CES announcement of their first A/V receiver to feature HDMI v1.4 switching should come as no surprise. And whereas they may be the first, they certainly won't be the last.
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