Last Update: 2012 Jan 16SUMMARYDo you need a TV that is 4:4:4 Chroma Capable?
Do you only use your TV for watching TV/movies and playing console video games? Then NO, you do not need a 4:4:4 capable TV.
Do you use your TV as a PC monitor or play PC video games? Then YES, it is strongly recommended you use a 4:4:4 capable TV.
For a list of TVs that can or cannot do 4:4:4, see post #2 in this thread.INTRODUCTION
Using TVs as PC monitors is becoming increasingly popular. In my opinion, the two biggest factors that makes a TV a good PC monitor is 1) low input lag, and 2) 4:4:4 chroma support. Unfortunately, both capabilities are never published in TV specifications, so the only way to get a definitive answer is through testing.
Thanks to frito and his “Input lag wars!” thread, input lag awareness and discussion is widely available. Lately, there has been a lot of 4:4:4 discussion within frito’s input lag wars thread, but it’s beginning to “pollute” that thread’s original intent. So to clean things up a bit, this thread was created to establish a centralized thread for 4:4:4 chroma discussions.THREAD PURPOSE
I anticipate this thread to be akin to frito’s input lag thread, but with emphasis on 4:4:4 chroma discussion instead. The first few posts will consist of three components:
- Overall background on chroma subsampling. This will describe *what* chroma subsampling is all about and describe some use cases where 4:4:4 chroma support is preferred.
- A FAQ for answering the most common questions regarding 4:4:4 capability, testing, and troubleshooting.
- And finally, a list of TVs with proven 4:4:4 capability. See post #2. (Note: I’ll keep the list up-to-date as long as I can).
After that, as long as its 4:4:4 related, anything goes. Also, by no means am I the authoritative source on all chroma subsampling matters. I’m still learning as I go. So if you find a mistake, or think of something else that needs to be included here, please let me know. Other than that, let the fun begin! BACKGROUNDB1) What is Chroma Subsampling?
Wikipedia explains chroma subsampling very well, so I’ll defer you to there: link
In summary… Chroma subsampling is a process where color information (a.k.a., chrominance or chroma) is sacrificed in order to reduce bandwidth. Why sacrifice color information? It’s because of the limitations of our eyes. The human eye has poor color acuity for detecting color details -- especially on a moving object.
Chroma subsampling sounds like an awful idea, but think it in terms of individual pixels (which is the level where subsampling works its magic). Let’s say you have a column of bright-red pixels and another adjacent column of dark-red pixels. With subsampling, you’ll end up with two columns of bright-red pixels instead. Unless you sit 1 cm away from your TV and have the eyes of a hawk, it’s highly unlikely you can detect the difference. Compound the fact that typical video footage is a series of different images being displayed at a rate of 24/30/60 fps, subsampling becomes imperceptible to the human eye.B2) What does “4:4:4” (or 4:2:2 or 4:2:0, etc) mean?
Again, Wikipedia explains this very well with illustrative examples: link
. For more technical descriptions, check out these pages: link1
For you audio-visual learners, this youtube video explains the nomenclature very well too: link
To sum it up, 4:4:4 means no subsampling is used at all -- so your image is displayed in its purest form. Anything less than 4:4:4 means original color information is lost.B3) I want to “future-proof / feature-proof” my TV as much as possible, do I still need 4:4:4?
Unless you have future plans on using your TV as a PC monitor, you still do not need a TV with 4:4:4 capability. Why? Because all commercial video footage (OTA TV, Cable, Satellite, Blurays, DVDs, Camcorders, etc) is already subsampled at the recording source. So there’s no point owning a 4:4:4 TV if you don’t have any 4:4:4 material.
In regards to modern game consoles like the Xbox360 and Playstation3, they *should* be able to produce 4:4:4 material (they’re essentially computers, after all). However, I have yet to find anything definitive on this topic. But for the sake of argument, let’s assume game consoles are 4:4:4 capable. With games updating at a rate of 30/60 fps, detecting pixel differences between 4:4:4 and non-4:4:4 under normal viewing conditions is impossible. So 4:4:4 or non-4:4:4 on game consoles becomes irrelevant.B4) Why do TV / Movie studios do chroma subsampling?
For the most part, it’s because of modern limitations in data storage capacity and transmission bandwidth.
For example, all blurays are subsampled down to 4:2:0 at the mastering studio (this is according to official bluray spec). As a result, most bluray titles have an average video bitrate of 25 Mbps. Assuming a 2 hour movie, you need a storage medium that can hold ~22.5 GBytes; which a bluray disc can do no problem. Now lets do 4:4:4 (no subsampling) on that same 2 hour movie. Going from 4:2:0 to 4:4:4 quadruples the amount of information required. So that 25 Mbps becomes 100 Mbps, and 22.5 GBytes becomes 90 GBytes; not even a dual-layer bluray disc can hold that much data.
If a bluray disc can’t hold it, don’t expect satellite/cable/fiber to transmit this kind of data either.
Note: the numbers used in this example are under review; will update when straightened outB5) Is a TV with 4:4:4 capability *REALLY* that important for a PC monitor?
This is a really delicate matter, as results will vary vastly across different TV brands, TV models, manufacturing variances, anti-glare coating, lighting conditions, your own vision acuity, etc.
The general consensus is that without 4:4:4 capability, only red/orange/yellow colored text will be blurry. However, in my personal experience, *everything* looks blurry and slightly off without 4:4:4. Picture quality is obviously subjective, but based on my A/B test (A = LG LD450 with 4:4:4, B = LG LD450 without 4:4:4), there is a clear night-and-day difference between the two.
Describing quality differences through words is difficult, so I will let pictures do the talking instead. Here are some A/B comparisons between 4:4:4 and non-4:4:4. All pictures were taken under identical conditions without any post-manipulation (except a resize function).
- Test 1: Windows Gadget Network Meter (reference image: link)
- Light-blue and green text on black background - result
- White and orange text on black background - result
- Light-blue text on black background - result
- Test 2: CNN Home Page (reference image: link)
- White text on red background - result
- “Real life” image - result
- Black text on white background - result
- Test 3: Chowhound Home Page (reference image: link)
- Black text on yellow background - result
- Bolded red text on white background - result
- Regular red text on white background - result
- Test 4: Hardforums Forum Page (reference image: link)
- Text graphic (White text w/ black shadow on orange background) - result
- Underlined bold orange text on dark gray background - result
- Underlined regular orange text on dark gray background - result
From the examples, you can clearly see quality differences (except for the “real life” image). The differences are even more pronounced in-person. So is 4:4:4 a necessity? I certainly think so, especially when it comes to text.TESTING AND TECHNICALT1) How do I know if my TV is 4:4:4 capable? -OR- How do I test for 4:4:4 capability?
Unfortunately, 4:4:4 capability is never listed in the spec sheets. So the only way to determine 4:4:4 capability is to test it yourself.
There are three ways of determining 4:4:4 capability: one is the quick-and-dirty / red-magenta method, the second is the Belle-Nuit method, and the third is the bspvette86 method.
- Quick-and-Dirty Method (a.k.a., Red-Magenta Method): Open the image found here: link. Make sure you’re at 100% zoom, and pay special attention to the Red and Magenta columns. On a 4:4:4 TV, the “Red” and “Magenta” text will be nice and sharp just like the text in the other columns. On a non-4:4:4 TV, the “Red” and “Magenta” text will be noticeably fuzzy, but the text in the other columns will be nice and sharp.
- Belle-Nuit Method: Open the image found here: link. Make sure you’re at 100% zoom, and pay special attention to the area with the red/cyan columns (to the left of the “20”). On a 4:4:4 TV, each red/cyan columns will be perfectly 1 pixel wide. On a non-4:4:4 TV, the red/cyan columns will have alternating thickness – some would be 1 pixel wide while others would be 2-3 pixels wide. Note: for the Bell-Nuit test, you may need a magnifying glass or macro lens to see the pixel widths clearly.
- bspvette86 Test: Forum member bspvette86 has created his own 4:4:4 test pattern, and you can find it here: link. On a 4:4:4 TV, every horizontal and vertical line is exactly one pixel in height and width, respectively. On a non-4:4:4 TV, pixels will appear faded and/or duplicated -- this is most noticeable with the red, blue, and magenta lines. Note: for the bspvette86 test, you may need a magnifying glass or macro lens to see the pixel widths clearly.
To give you an idea of what 4:4:4 and non-4:4:4 results should look like, check out these three examples: link1
, and link3
.T2) My TV is said to be 4:4:4 capable, but its failing the 4:4:4 tests, what’s going on?
The easiest fix is to use a DVI->HDMI cable to connect your PC to your TV. In some rare cases though, a DVI->HDMI connection will still cause 4:4:4 to fail. Additional details on this will be discussed in question T3.
For some TVs, you have to set specific TV settings to enable 4:4:4 capability. These include things like switching to special picture modes (i.e., “Game” or “PC” mode) or relabeling your input ports. If your TV has these types of settings, give it a try and see if it passes the 4:4:4 tests.
For the TVs that have already been tested and require these special tweaks, I’ll be sure to note them in the 4:4:4 TV list.T3) I’m using a DVI->HDMI cable, but I’m still failing 4:4:4, what’s going on?
Unfortunately, I don’t have a technical explanation why this happens to some people. The popular theory is that during the EDID exchange between video card and TV, the HDMI audio extensions becomes enabled over DVI. When HDMI audio extensions are enabled, *something* causes 4:4:4 to fail. I have no idea if this is a TV issue, or a video card issue, or a HDMI issue, or an EDID specification issue, or a combination.
The good news though, there is a fix that has a high success of getting 4:4:4 working again over a DVI->HDMI connection. This fix is commonly known as the EDID Override fix or the Disable HDMI Audio fix, which will be described in [the next question].T4) What is the EDID Override fix? -OR- What is the Disable HDMI Audio fix?
The EDID Override fix (a.k.a., Disable HDMI Audio fix) disables the HDMI audio extensions after the initial EDID exchange takes place. I don’t know the technical details on why this fix works, it just does.
So how do you install the EDID Override fix? The Internet is littered with mini- How To’s, but the two that I’ve found to be the easiest to understand (even for those not technically savvy) are:
Note1: Both walkthroughs achieve the same result, they just have different approaches. So go with whichever one you think easier. I personally prefer the currysauce way.
Note2: Both walkthroughs are written for nvidia video cards, but it’s the same for amd/ati video cards too.T5) Is there an EDID Override fix for Linux PCs?
Yes, there is. Check this out: link
.T6) I want to use a HDMI->HDMI cable (because I want HDMI audio), can I still get 4:4:4?
From my experience and observations, the answer is no. As mentioned previously, *something* relating to HDMI audio extensions causes 4:4:4 to fail. Only by disabling the HDMI audio extensions (via a DVI->HDMI cable and/or EDID Override) will 4:4:4 become enabled.
There was some detailed discussion about this issue in the LG LD450 thread between galneon and a few others (starting at post #800
and ending at post #878), but nothing was ever conclusively determined.
If anyone has insights to this matter, then please let us know. If we can isolate the problem and develop a fix, then a lot of folks would benefit from it.
Note: with some 2011 TVs (ex., Sony HX729 and Samsung D6000), 4:4:4 is available even if HDMI audio is enabled. Hopefully this will become the norm and we'll see more 4:4:4 + HDMI audio TVs in the future.T7) I want to take a chance on an untested TV. Are there features/indicators that will increase my probability of finding a 4:4:4 capable TV?
Generally, TVs with fancy features like 120+ Hz frame interpolation and dynamic image processing will not be 4:4:4 capable. These TVs are designed to manipulate the image, and therefore may be “hard-coded” with features that prevent 4:4:4 rendering. So go for the TVs that are minimalistic as possible (in other words, the cheap TVs).
I want to reiterate that this is only a rule-of-thumb. There does exist feature rich TVs that are indeed 4:4:4 capable. One prime example is the Sony EX720 series.OTHER LINKS OF INTEREST
Here's a few other threads about 4:4:4 I've found. Most are inactive now, but still good sources of archival data. Special thanks to each thread's respective author.
- LCD Televisions with 4:4:4 Subsampling and low Input Lag
- input lag wars!
(there's a lot of 4:4:4 info sprinkled throughout, but please keep 4:4:4 discussions in this thread and not over there)
- 4:4:4 Chroma Sampling - Questions
- 4:4:4 Chroma needed for HDTV as a computer monitor?
- Who can name a Panasonic TV that achieves full chroma resolution (4:4:4)?