HD 101: The difference between sequential and side by side 3D
By Ben Drawbaugh 
posted January 12th 2010 5:13PM
posted January 12th 2010 5:13PM
Sequential transmission to sequential display
Side by side transmission to sequential display
All this 3D is cool and all but it can be difficult to understand all the new formats and as much as people want it, there's no new format war here. In fact the differences in the 3D technologies are more like the differences between 720p and 1080i or LCDs and plasmas. We talked a lot about the differences between circular polarized and active shutter glass systems in our 3D is coming home feature (these two are like LCD vs plasma) but we didn't talk about the ways to store and transmit 3D (kinda of like 720p vs 1080i). There are more than two ways, but since sequential is what the Blu-ray spec and active shutter TVs use, and side by side is what DirecTV announced, we're going to focus on them. Now just like 720p vs 1080i, a signal can be transmitted in either format but still displayed differently on the HDTV. And also like a 1080p HDTV can really only display 1080p images (everything else is converted) a sequential 3DTV can only display sequential 3D, this of course means the TV converts it. In the case of Blu-ray, the video is sent out of the player at 1080p 24 frames per second, per eye; or 48 frames per second. This signal goes to the TV but the glasses are what ensures each eye sees the correct image -- pretty simple right. But for side by side systems like DirecTV is using, a single 1080p frame that holds both the right and left eye's images is sent at 24 frames per second. The TV receives this signal, splits it into two frames, displays them sequentially and then stretches 'em out. Obviously this isn't as good as Blu-ray, but it uses way less bandwidth and makes it so DirecTV can just release a firmware update instead of replacing all the set-top boxes. It is expected that cable companies will use the same technique -- the reason exceptions were added to the HDMI spec -- but even ESPN said it wasn't exactly sure what format it would use.
Good little article. I hadn't read too much on this and was wondering how direcTV was getting by with just a firmware update.
@madgamer2000
What's interesting is that no firmware is required to decode the side by side 3D signal. They only needed to update the UI to render over 3D and the HDMI to shake with a 3D TV so it knows the display can handle the 3D signal.
3D is pointless
@(Unverified)
so is 1080p, shit so is T.V but moving forward is moving forward. The closer we get to virtual reality/holodeck the better.
@Ryujin 3D is useless as it has no commercial value.
This is not a new concept and is nothing more than a "GIMMIC"
I am all for "CAVES" , "Holodecks", but yet again Content,Content,Content and cost , cost , cost.
I am also disappointing in the very slow roll out for HD and the fact that we are moving to 3D so quickly, full HD TV for our current TV's being years away.
So i guess they completely killed hdm1.4 for now. Also any word if you a/v receiver can pas the 3d loop onto the the tv?
I wonder if we will get to a point where there will be an option when you watch a channel to convert to 2d, 2d HD, 3d, 3d HD.
Good overview of past technology, but they do not state any of the drawabacks:
side-by-side: half horizontal resolution
"Xpol" line-inerleaved: half vertical resolution.
This also means, if 3D content is stored in side-by-side and displayed as line-interleaved, you end up with a quarter of the originial resolution.
Anaglyph / ColorCode: horrific color quality, headache inducing.
Checkerboard: half resolution, but since it's somewhat "diagonally" half, it's easier to upscale back to original frames.
Full HD sequential: requires frame parity signalling. HDMI 1.4 does this by placement in an enlarged video frame. Others seem to sacrifice the last line for "blue-lining". The "noticebale flicker" they mention occurs only when the frame rate can not be doubled for the transmission. HDMI 1.4 does this doubling.
Above-below (also called over-under, top-bottom): half vertical resolution.
line interleaved and checkerboard can not be encoded with the current video codecs, because the 4:2:0 color compression would result in sharing the same color for the left and right frames.