
Stereographic 3D hasn't arrived until it arrives in the home. TDVision has a proposal: a standard that works with any display, with both 2D and 3D in one stream, with no additional hardware. |
We have a proposal for the mass adoption of 3D, using our TDVCodec 2D+Delta encoding and decoding system. TDVision's "Encode Once, Deploy Everywhere" methodology means that, for the first time ever, videos can be viewed simultaneously in 3D and 2D from a single file, at the full HD resolution per eye, on every existing display.
As we have been focused on the mass adoption of stereoscopic 3D in the home, we believe that the best way to achieve it is by providing four key elements.
QUALITY
TDVision's approach to Full HD Stereoscopic Encoding calls for full 1080p per eye, no loss in color, quality or resolution, and no interpolation.
What some people did in olden times when encoding 3D for the home was to squeeze the left view and the right view into a single 1920x1080 frame. That meant discarding half of the pixels in order for both eyes to fit, then scaling each of these half-frames back up to fill the entire frame.
This up-scaling interpolation has to invent new sets of pixels, which inevitably creates the same kinds of artifacts you see with up-converting 2D - aliasing, pixelation and bleeding colors.
Even worse for 3D, up-conversion also interpolates depth. This compromises the 3D images, because they now have the wrong depth cues. It also compromises the work of artists who simply want to capture their artistic vision, and convey it as clearly as possible.
Our TDVCodec 2D+Delta stores the full resolution of both left and right views into the video stream. We compare the two views, and extract the difference information, or the delta, between the two views, without repeating any pixels that are the same in both views. When we decompress, we have all the pixels from both views, with no scaling or interpolation. The result: mathematically lossless compression.
COMPATIBILITY
There are 3D formats being proposed that offer, say, a side-by-side view, or two views in a single frame, whether by checkerboard patterns or other methods.
What happens when you turn to a channel showing one of these? If you don't have a 3D television, you will see double or blurry images. Under these proposals, program content providers will need a complete, separate channel to service the legacy world.
Our goal is to create the same kind of seamless experience that you saw in the transition from black and white to color. A single signal provided an image that was compatible with every television.
We built our format in such a way that if you have a 2D television, you'll see the 3D broadcast as full resolution 2D HD. The encoded broadcast passes through the decoder chip you already have in your television. It looks at the signal and says, I see this 3D information, but can't do anything with it. I'm going to pass over the 3D, and just display the 2D information.
An updated decoder says, I see 3D information, and guess what? I have a 3D display, so I know how to play this back as 3D.
This gives us a variety of options. Our TDVCodec is fully compatible with MPEG2, H.264, VC-1 and MVC (Multi View Coding), so, for example, our TDVCodec can be included in a file encoded for Blu-ray. Put that disk in a current Blu-ray player, and it will play in 2D. Put the same disk in an updated player that supports 3D, and it plays back in 3D.
We were the first company in the world showing such an implementation, more than a year ago.
DISPLAY AGNOSTIC
We are also compatible with the nuances of preparing the 3D signal for multiple types of native formats for each kind of display: 3D DLP, 3D LCD, dual projectors, etc. - all of them at the best native resolution to offer a prime experience to the user.
We are also agnostic toward the specifics of the kind of 3D output. To be honest, we're not the biggest fans of anaglyph, but if that's what somebody wants, it's simple. We just shift the color values before we pop them out of the HDMI port.
What if someone wants a checkerboard pattern between the two views? Well, just a simple process called pixel addressing is needed. Hardware in display devices already does that, sending the right pixels to the right places.
The same is true for sideby- side or dual device output. We push the mapped pixels through the HDMI cable, and there you have it. It's basically just dumping out the frame buffer, as is.
SOFTWARE/FIRMWARE SOLUTION (NO ADDITIONAL HARDWARE)
The fourth part of speeding the widespread adoption of 3D is that we should not require any extra hardware.
Stereoscopic 3D can be enabled by pushing our TDVCodec via a firmware update on certain chipsets or a simple software
download for Blu-ray players, PCs and set-top boxes, so that they can work in 3D immediately.
Our MPEG-based compression compatibility means that any existing MPEG systems can be used for storage, transport and 2D playback seamlessly, without the need for any additional hardware.
THE FUTURE
We have recently partnered with a company called Magnum Semiconductor to create the world's first Full HD Stereoscopic 3D (1920x1080p per eye) realtime encoder, using this same "Encode Once, Deploy Everywhere" approach.
Instead of the long encode times for, say, Blu-ray compression, our partnership with Magnum Semiconductor allows us to encode full 1920x1080p/60 for both eyes in under 20 ms. This very tight encoding time opens up stereoscopic 3D encoding for DBS, cable and IPTV - as well as studio dailies and live-event streaming to cinemas.
Broadcast also benefits from real-time encoding.
As I mentioned, our major advantage is that a single stream is fully compatible with both 2D and 3D displays, an "In 3D HD where available" approach.
We are not putting this proposal forward because we want to rule the world, or we want to win the war. We do it because we want to be responsible to this world of high definition 3D. We believe that this does justice to all these years of technological evolution.
Our number one goal is the mass adoption of every aspect of 3D technology.
There have been a lot of 3D movies in the past couple of years, so let's get them out on Blu-ray. We'd also like to see more 3D content going out on existing channels. We can roll it out gradually, as we did with HD. A late night talk show in 3D, a sportscast in 3D, even an entire 3D network - we could do it tomorrow.
It just takes the will of people who realize that you don't have to wait. You can have everything, and you can have it now.
Ethan Schur
Los Angeles, California USA
Ethan is the Chief Marketing Officer for TDVision Systems, and Chief Standards Engineer for their contributions to SMPTE, SCTE, ATSC, CEA and others. He is also the chair of 3D@Home's ST3, their Worldwide promotional subgroup. Ethan's experience includes post houses, studios and military virtual reality applications, and Electronic Arts, where he was a build engineer working with developer toolkits, internal logic and optimization.