VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Thu Dec 18 2014 - 14:31:56 CST

Hi,
  I wanted to send a quick update. After updating video drivers and
disabling the "deep color" display mode and upgrading the TV firmware
on the LG 4K TV I've been testing, I was able to get row-interleaved
stereo working with VMD on a GeForce 980, at full 4K resolution and without
any color bleeding from chrominance downsampling. I've been testing the
LG model 49UB8500-UA, but I believe that the same results would likely
apply to their larger 55", 60", etc models.

Here are my observations about getting the TV working with VMD:
 - If you drive the TV at native 4K resolution (3840x2160), and you have
   an up-to-date video driver and a GPU that can handle the full resolution
   without chrominance downsampling, you can simply enable "row-interleaved"
   stereo mode in VMD (nothing has to be done with the TV itself) and you'll
   get 3-D (you may have to enable VMD 3-D eye swap, particularly if the VMD
   OpenGL window gets moved around).

 - If you drive the TV at any resolution _below_ the native 4K hardware
   resolution (e.g. 1080p or less), the TV's built-in 3-D stereo decoder
   mode MUST be activated, and then you should set VMD's stereo mode to
   match whatever the TV's built-in stereo 3-D decoder is set to.

So far, we have driven the TV at full 4K resolution and stereo on Linux,
but we have not (yet) found a Mac laptop that is able to drive the TV
over HDMI at full 4K resolution. All of the Macs we have tried have
all maxed out at 1080p thus far. We haven't yet tried Windows laptops yet.
The various stereo modes worked fine with the Mac laptops, albeit at
only 1080p resolution.

One remaining issue I have observed when using stereo 3-D with the TV
is some apparent flicker during constantly-updating VMD rotation draws,
and an apparent lack of vertical retrace synchronization with the GPU.
So far this effect is relatively minor, but it is worth noting.
I'm looking into whether this is some video driver bug or something
else. I'll send further updates when I get it sorted out.

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Wed, Dec 17, 2014 at 10:45:24AM -0600, John Stone wrote:
> Hi,
> I think you missed my point -- row-interleaved hasn't worked for me
> when running at 4K resolution, only side-by-side and over-under have worked
> so far when running at the full display resolution. Row interleaved is one
> of the modes that could have issues if you've got downsampled
> chrominance (in my case the LG TV just disables these modes entirely).
>
> For the LG TVs I'm testing currently, the display panel appears to be
> row-interleaved at the hardware level, so running row-interleaved is the
> best choice for VMD, but I have to find a way to get the display to run
> at full 4K resolution with full resolution chrominance data. I'm going to
> try updating to a newer driver version and newer TV firmware and see if
> either of those has any impact. Another potential gotcha I'm working
> around is that some TVs support 30-bit color (10-bit per color channel)
> and that eats some of the available HDMI bandwidth. It is possible that
> row, column, and checkerboard stereo modes might be workable on the
> shallow color depth modes but not in 30-bit color. I'm working on testing
> that next...
>
> Cheers,
> John
>
> On Wed, Dec 17, 2014 at 05:34:14PM +0100, Norman Geist wrote:
> > But isn't more comfortable using the row interleaved stereo mode anyway,
> > where one hasn't to deal with all of that possible issues? It will have full
> > screen stereo, windowed stereo, and the TV doesn't even know that 3D content
> > is present. The only disturbing thing is the eye switch which comes by
> > moving and placing the windows.
> >
> > Or do I miss something?
> >
> > Norman Geist.
> >
> >
> > > -----Ursprüngliche Nachricht-----
> > > Von: John Stone [mailto:johns_at_ks.uiuc.edu]
> > > Gesendet: Mittwoch, 17. Dezember 2014 17:12
> > > An: Norman Geist
> > > Cc: 'Smolin, Nikolai'; VMD Mailing List
> > > Betreff: Re: vmd-l: VMD with 3D TV
> > >
> > > Hi,
> > > One interesting observation I had in testing VMD with some of the new
> > > LG TVs is that although the LG 4K TV supports 6 different stereo modes,
> > > only some of them are usable when the video driver is set for the
> > > native
> > > 4K display resolution of the TV, at least in my testing with a GTX 980
> > > and driver version 343.22. One potential catch with this is that video
> > > cards using HDMI 1.x outputs may downsample the color information by 2x
> > > or more, converting to so-called 4:2:2 or 4:2:0 color formats.
> > >
> > > I think that the downsampled color formats are inherently unworkable
> > > with
> > > row-interleaved, column-interleaved, and checkerboard stereo formats,
> > > which in the case of the LG TVs I've been testing leaves only the
> > > side-by-side and over-under video format. The drawback of the
> > > side-by-side and over-under formats is that they only work correctly
> > > with a full-screen window, and clearly that is somewhat limiting.
> > >
> > > I'm currently trying to sort out a video driver version that can run
> > > the TV without any downsampling of chrominance information, and I'm
> > > hoping
> > > that might allow the LG TVs I'm testing to run at full 4K resolution
> > > while also supporting windowed stereo. If you drive the LG TVs at
> > > 1080p,
> > > they do support all of the stereo modes, which is one reason I suspect
> > > that
> > > downsampled chrominance might causing the limitation in 4K modes.
> > >
> > > Cheers,
> > > John Stone
> > > vmd_at_ks.uiuc.edu
> > >
> > > On Mon, Dec 15, 2014 at 08:43:12AM +0100, Norman Geist wrote:
> > > > VMD also offers the stereo mode row Interleaved, so you can use
> > > any
> > > > passive 3D Display. The graphics card or machine doesn't really
> > > matter
> > > > than, except of supporting the 4k resolution.
> > > >
> > > >
> > > >
> > > > Norman Geist.
> > > >
> > > >
> > > >
> > > > Von: owner-vmd-l_at_ks.uiuc.edu [mailto:owner-vmd-l_at_ks.uiuc.edu] Im
> > > Auftrag
> > > > von Smolin, Nikolai
> > > > Gesendet: Freitag, 12. Dezember 2014 17:10
> > > > An: vmd-l_at_ks.uiuc.edu
> > > > Betreff: vmd-l: VMD with 3D TV
> > > >
> > > >
> > > >
> > > > Dear All,
> > > >
> > > > I am thinking to use VMD with 4k 3D TV.
> > > >
> > > > What is the best way to do it.
> > > >
> > > > Linux or Windows? which graphic card? Which TV is best for this?
> > > >
> > > > Now I have a Suse 13.1 with Quadro 2000D Workstation Graphics
> > > Card -
> > > > 1024MB, GDDR5, PCI Express 2.0 x16, Dual DVI, DirectX 11, Single-
> > > Slot.
> > > >
> > > > Can I use this workstation with 4k 3D TV.
> > > >
> > > >
> > > >
> > > > Thanks,
> > > >
> > > > Nikolai
> > > >
> > > > ------------------------------------------------------------------
> > > ---------------------------------------
> > > > Nikolai Smolin, Ph.D.
> > > > Research Associate
> > > >
> > > > Department of Cell and Molecular Physiology
> > > >
> > > > Loyola University Chicago
> > > >
> > > > 2160 South First Avenue
> > > >
> > > > Maywood, IL 60153
> > > > Phone : 708 - 216 - 5158
> > > >
> > > > E-mail : [1]nikolai.smolin_at_gmail.com
> > > > E-mail : [2]nsmolin_at_luc.edu
> > > > www : [3]https://sites.google.com/site/nikolaismolin/
> > > >
> > > > References
> > > >
> > > > Visible links
> > > > 1. mailto:nikolai.smolin_at_gmail.com
> > > > 2. mailto:nsmolin_at_luc.edu
> > > > 3. https://sites.google.com/site/nikolaismolin/
> > >
> > > --
> > > NIH Center for Macromolecular Modeling and Bioinformatics
> > > Beckman Institute for Advanced Science and Technology
> > > University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
> > > http://www.ks.uiuc.edu/~johns/ Phone: 217-244-3349
> > > http://www.ks.uiuc.edu/Research/vmd/
> >
>
> --
> NIH Center for Macromolecular Modeling and Bioinformatics
> Beckman Institute for Advanced Science and Technology
> University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
> http://www.ks.uiuc.edu/~johns/ Phone: 217-244-3349
> http://www.ks.uiuc.edu/Research/vmd/ 

-- 
NIH Center for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
http://www.ks.uiuc.edu/~johns/           Phone: 217-244-3349
http://www.ks.uiuc.edu/Research/vmd/