Tuesday, August 31, 2010

Got 3-D? A Media PC does that too!

This post started out life as a quick project to setup 3-D on my Media PC, but I quickly realized that there is a lot to explore and some real interesting background to this technology.  As many of you are aware 3-D television isn't very new at all.  What is new is the entertainment industry is making another run at trying to hook people into 3-D technology.  If they succeed, you can be sure it will drive another wave of upgrades for the consumer, (obviously) higher theater ticket prices, and even another lock-in for pay TV.  Naturally, my goal is quite the opposite.  How can we have fun with 3-D without the high cost?  If you like your cake, and want to eat it too, read on!

Since a Media PC can be the do-it-all center for driving entertainment in your living room, it makes sense to wonder what it would take to get it to display 3-D as well.   Well, the good news is that it can, but there are few things to talk about first.

This first post will cover what you need to get ready for 3-D on your Media PC.  I'll do several more posts each covering related topics:
Now, ready for some 3-D fun?

Now, you are probably thinking that you have to wear those silly red-blue glasses that you remember as a kid (like this):

Absolutely not!  Technology has improved dramatically since then.  The 3-D glasses of today will make you look far cooler (okay, maybe cooler is a stretch).

Older 3-D technology (that used the red-blue) glasses was pretty simple but had it's advantages.  The most important advantage is that it worked with any projection system or TV.  No special viewing equipment was needed.  All you needed were those goofy glasses and you were good to go.  Unfortunately, the red-blue lenses did terrible things to the colors of the movie so the illusion of 3-D was an obvious trick that you never really believed was real.  If you want to read more about older 3-D (known as Anaglyph, read about it here).

The new 3-D technology (available now), uses what is called Alternate-frame sequencing.  Using special active shutter glasses, each eye can be presented with it's own image/view.  Your brain does the rest and you see a fully 3-D image.  Unlike the Anaglyph technique, the colors aren't distorted and what you see looks truly realistic.

The theaters of today use a very similar technology with polarization 3-D and (inexpensive) polarized glasses.  The two techniques (Alternate-frame sequencing and polarization 3-D) produce nearly identical results.  The main difference is that theaters use a projection system that isn't yet practical in the home (so we are stuck with active shutter glasses).   Finally, there is an another method that is being developed called Autostereoscopy or Auto 3-D (3-D without the need for glasses).  This has promise, but has yet to be available in the home at reasonable prices.

So that leaves us with technologies that that use Alternate-frame sequencing.  The good news is that it works really well.  Let's see what we need to get this working in your home.   You need four major pieces:  3-D capable TV, 3-D active shutter glasses, 3-D capable player, and finally you need some 3-D game or media to watch.  Let's go over each one.

1. a 3-D ready TV

When I recently upgraded to a new TV, I was aware that 3-D was coming.  I looked for an inexpensive TV that not only did 1080P but was also 3-D Ready.  Of course, I had no idea at the time what 3-D technology was about back then.  I just saw the 3-D Ready logo and was happy knowing that someday I'd get to watch 3-D stuff.  Well that day has arrived.
So, what does 3-D ready mean in a TV?  One prerequisite of 3-D TVs is their ability to display at a refresh rate of 120Hz or higher (two times the normal 60Hz).  This is necessary because the TV needs to display twice as many frames per second (one image for each eye).  It is then the job of the active shutter glasses to alternatively block each left-right eye view 120 times per second.  Obviously the glasses need to coordinate their work with the TV itself so that everything is in sync.
So, how do the TV and glasses stay in sync?  If you look on the back of your set, you might see a special plug marked "3-D glasses emitter".

You can purchase a special IR emitter that plugs into your TV and sends a signal to any active shutter glasses in your TV viewing area.  Seems simple enough?

There is actually another method of syncing glasses (for DLP TVs) that doesn't require a special emitter called DLP link.  The TV displays a white "flash" that the glasses can sense and allows them to stay in sync.  So, which method should you use (emitter or no emitter), if you have a choice?  That will probably depend on your TV.

Turns out that my 2009 65" Mitsubishi TV has a "feature" that makes using an IR emitter undesirable.  On pre-2010 Mitsubishi DLP TVs they forgot to turn off the DLP link "flash" when using an IR emitter.  This causes the colors to be off when using glasses designed for IR emitters.  So, if you have an "older" 3-D ready DLP TV make sure you can turn off the DLP link feature or use only DLP link glasses.  You can read about this issue here on AVSforum.

Finally, the last aspect of 3-D readiness is the signal format itself coming from your Media PC, game system or DVR.   The 3-D signal is going to be delivered over HDMI, but there are actually multiple standards (and quality levels for doing this).

There are four standard 3-D signal formats called Checkerboard, Side-by-Side, Frame Sequential, and Frame Packing.  You can read a really good summary here.  You don't really need to worry about the differences so much as you need to know what format your TV and player support.

In my case, my DLP TV only supports Checkerboard.  Newer (and more expensive) TVs support additional formats such as Side-by-Side.   The advantage of the Checkerboard format is that it actually doesn't require any additional bandwidth over the HDMI cable (and is covered under HDMI 1.3 spec).  In that sense Checkerboard is a lot like interlaced TV signals (the signal data is cut in half so that twice as much information can be sent).   The other formats send twice as much data (and have higher quality).

If your system can support one of the full-bandwidth 3-D formats (Side-by-Side, etc.), then by all means use it.  Otherwise just use Checkerboard and be happy.

2.  Active shutter glasses

Active shutter glasses are still pretty new so they are frankly a bit expensive.  I'd expect them to drop in price significantly in the near future.  You also have to be careful to buy glasses that are compatible with whatever system you are using.  See the discussion above about using a 3-D IR emitter v.s. DLP link.

Since my best quality option for my TV is to use glasses that don't require an emitter, I opted for glasses made by Optoma (model BG-ZD101).  I've read good reviews about them and while they aren't the cheapest solution, they seem to be the best quality.

A week later, my Optoma's arrived and they are indeed a nice set of glasses.  They come with three interchangeable nose pieces.   They don't have rechargeable batteries like some other glasses, but I figure the batteries might just last far longer than my interest in playing with 3-D.

They have a power button on the top of the glasses.  When you activate them (and they sync to your TV), you will notice a slight dimming of your view as each eye is being alternatively blanked.  Pretty cool technology if you ask me!

3. a 3-D capable player

Along with your 3-D ready TV, you need some system that can send a 3-D signal to your TV.

Before we go on, you may have read about 3-D kits available for your 3-D ready TV.  These kits usually include things like active shutter glasses, an emitter, and a HDMI cable.  You may or may not find these useful or a good deal.

However, these kits can also include an adapter for 3-D signals for your TV.   An adapter might be necessary if your 3-D player outputs a signal that your TV doesn't support (see discussion above).  For example, if you have a BluRay player that outputs 3-D in the Side-by-Side format and your DLP TV only supports Checkerboard input, then you will need an adapter.  Here are two examples:

Here is yet another advantage to having a Media PC.   My Media PC uses ATI's embedded graphics processor called the Radeon HD 4200.   With some special drivers, the HD 4200 is capable of outputting the 3-D Checkerboard format (directly) as required by my 3-D ready TV.  No adapter needed!

The software needed by ATI's 3-D solution is made by a company called IZ3D.  The drivers are free for your use on ATI systems.   Just download, install and you are ready to play with 3-D.  Here is a link to the drivers.  I installed the Beta version, just to make sure I had the latest features.

Keep in mind that I'm using a motherboard with an embedded graphics processor (i.e. a really cheap solution).  If your goal is to play hard-core 3-D games, chances are really good that you will want to upgrade to a much more capable discrete graphics card.   Fortunately, graphics cards aren't that expensive.  However, since 3-D support is changing so fast, if you are like me you are deferring that option until later.   For now, I think it is really cool that an embedded system works at all for 3-D (and it does!).

4. Software and 3-D content.

Now that we have all of the hardware and drivers needed for 3-D what is left?

Well, in order to play movies we need software that understands and will decode the 3-D formats.  For games and BluRay titles we need the 3-D versions.  Finally there is software to convert 2-D movies into 3-D (either on the fly or offline).  I'll explore how these options work on my Media PC in the next few post.

Total cost invested to play with real 3-D on my Media PC: $80.  Not too bad!

More to come...

1 comment:

  1. Great intro to 3D - was wondering what it was all about and how it worked. One thing I read recently is docters are concerned about the long term 3D viewing and the effect on the eyes. I will be most interested in the systems down the road that won't require glasses, as I can't see the masses adopting it if they have to wear the glasses all the times. In the few 3D movies I have seen, my kids end up taking the glasses off half way through, saying it bothered them.

    Keep up the good work.

    Still want to do your LED mod one of these day, but kind of tired of fiddling with my HTPC(Its always something with that thing)


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