whats the difference in quality between HDMI and composite?

[Semper Fi]

How great of a difference would I see in visual quality between HDMI and composite cables when watching DVDs on my HDTV?

Is HDMI a higher calibur connection than composite?

[[XC] leviathan18]

THIS ARE THE BASICS (sorry if it is too long)

COMPONENT VIDEO
If you are just getting into home theater you will no doubt be confused by a lot of the jargon. And since the term component video is sure to befuddle just about everyone, here's a little primer on the subject. It might sound a little technical at first, but if you've got a DVD player, read on for some important information.
Starting at the beginning: RGB
Believe it or not, your eyes can see only three colors—red, green, and blue. All of the other colors and shades of the spectrum you perceive are the result of your brain interpreting the mix of red, green, and blue signals coming from your eyes. Pigments of your imagination, you might call them. (Sorry.)
Therefore, since your eyes only see red, green, and blue, a video system needs to capture and reproduce only red, green, and blue, or RGB as it's called. The camera must capture RGB on the front end. That information must be delivered accurately to your television or projector which must display RGB. By varying the intensity of red, green, and blue, every color of the spectrum can be reproduced. Voila. Perfectly natural color on your screen.
A Problem: Bandwidth
So how do you transport an image from the camera to your TV or projector? You could transmit it in the RGB format in which the camera first captured it. However, RGB is a bandwidth hog and bandwidth is expensive. So the first thing that happens is RGB is converted into a more compact format. This format is component video.
Component video consists of three signals. The first is the luminance signal, which indicates brightness or black & white information that is contained in the original RGB signal. It is referred to as the "Y" component. The second and third signals are called "color difference" signals which indicate how much blue and red there is relative to luminance. The blue component is "B-Y" and the red component is "R-Y". The color difference signals are mathematical derivatives of the RGB signal.
Green doesn't need to be transmitted as a separate signal since it can be inferred from the "Y, B-Y, R-Y" combination. The display device knows how bright the image is from the Y component, and since it knows how much is blue and red, it figures the rest must be green so it fills it in.
Once we've got our video information packaged up in component video format we've reduced bandwidth requirements by a factor of 3 to 2. But more compression was required for broadcast purposes. So back in 1953 when color television was born, a technique was developed to compress all of the component video information into one signal for broadcast. That one signal defined by the National Television Standards Committee (NTSC) is known as composite video.
Composite video shows up everywhere these days. It is (except for HDTV) what comes over the air to your TV's antenna, or through the coaxial cable from your cable TV provider. The yellow "video" jacks on the back of your VCR, laserdisc player or DVD player all output composite video.
The good news is that it only takes one wire to carry a composite video signal. The bad news is that the display system, whether it's a television or projector, needs to un-compress the composite signal, restore it to its original three-signal component video format, and then derive from that the RGB information for final display.
The problem is that picture information is lost when component video is compressed into composite format. Furthermore, once you pack luminance (Y) and chrominance (C) information into one signal, it cannot ever be separated cleanly again. So when the television or projector tries to convert the composite signal back to component video, it can't recover the entire original signal. The result is that the final video image on the screen is diminished—the picture is not as crisp and clean, and the colors aren't as accurate and rich as they would have been had the composite video compression been avoided.
So what does all this mean to you?
If you want good picture quality, there's some amazingly good news here. The news is this: DVDs are encoded in component video!. This is a big step forward since VHS tapes and laserdiscs are encoded in composite video. So the signal information in those media is already diminished and compromised. But DVD is a different animal—not only is it more compact and easy to use, but a much higher quality format is on the DVD itself. All you need to do is take advantage of it.
To do that, you need a DVD player with component video output, and a television or projector with component video input. You can connect the two with a three-wire component video cable. When you do this, you transfer the high quality signal from the DVD straight into your display system without it ever being converted to composite video. The result—better detail, a cleaner picture, and more accurate and richer color.
But wait, there's more. Let's say you are one of the vast majority of consumers out there whose DVD player doesn't have component video outputs or your television or projector doesn't take component video input. What you then have is two connection options.
First, you can do what most people do--use the simple yellow (RCA) video jacks. Actually this cable is often bound together with the audio connectors to make it even easier—yellow for video and red and white for audio. Couldn't be easier, right? Big mistake.
The second connection option (the better option) is that you can use the clumsy 4-pin S-video jacks. This often requires a trip to the electronics store to get a more expensive cable. Most people don't want to bother. So they use the yellow RCA jacks because they are labeled VIDEO, and because that's the cable that came with the DVD player. Once they hook it up and turn it on, they find that the picture looks better than their VCR. So they are happy and forget about S-video. This is of course the wrong thing to do.
Why? Because by using the yellow RCA video jacks, you are forcing your DVD player to down-convert all that great component video information on the DVD to lowly composite video in order to transmit it to your television or projector. You lose much of the picture quality that the DVD can deliver by doing this. OK, it looks better than your VCR. But you aren't getting the best picture you can get.
So the alternative, S-video, is a MUCH better solution. An S-video cable actually carries two separate signals, one for luminance (Y) and one for chrominance or color (C). The Y signal is the same as in the native component video format. And the C is simply a combination of the B-Y and R-Y color difference signals. (Sometimes you will see S-video referred to as Y/C.) By keeping luminance and chrominance information separate on two wires it prevents most of the signal degradation that is inherent in the conversion to single-wire composite video.
So. If you've got a DVD player and want to give yourself an instant video system upgrade, replace the composite video RCA cable (the one with the yellow plugs) with an S-video cable (round connector with four little pins). It's simple and inexpensive, and you will get a much better picture.
Use component video if you have it
If you have component video output on your DVD player and your TV or projector can take that signal, use it. DVD players with this output usually have three RCA jacks which are color-coded green, blue, and red. They are labeled either Y, B-Y, R-Y, or alternatively Y, Pb, Pr, or Y, Cb, Cr. For practical purposes they are all the same thing. If your television or projector also has the same three RCA jacks, just connect them with a three-wire component video cable making sure the colors match up on both ends (or you can use three standard composite video cables to do the same thing).
Frequently a projector will take component video, but only through a VGA port, commonly a 15-pin D-sub like the output ports on a PC. In this case you will need a cable that has the three RCA jacks on one end for the DVD player, and a 15-pin D-sub VGA connector on the other. You can order this cable from most projector manufacturers that market projectors with this interface.

[[XC] leviathan18]

NOW HDMI

HDMI

Developed by Sony, Hitachi, Thomson (RCA), Philips, Matsu:banana::banana::banana::banana:a (Panasonic), Toshiba and Silicon Image, the High-Definition Multimedia Interface (HDMI) has emerged as the connection standard for HDTV and the consumer electronics market. HDMI is the first and only digital interface to combine uncompressed high-definition video, multi-channel audio and intelligent format and command data in a single digital interface. For your end-users, use of a single cable for audio and video dramatically simplifies home theater system installation and eliminates the cable quagmire typically associated with home theater system components. Most importantly, HDMI offers significant advantages over analog A/V connections, including the ability to transmit uncompressed digital video and audio content. In addition to numerous device and display manufacturers, Hollywood studios and cable and satellite operators also support HDMI.

HDMI is fully backward compatible with PCs,displays and consumer electronics devices incorporating the Digital Visual Interface (DVI) standard. Both HDMI and DVI were pioneered by Silicon Image and are based on TMDS®, Silicon Image's powerful, high-speed, serial link technology. HDMI supports standard, enhanced, or high-definition video, plus multi-channel digital audio on a single cable. It transmits all ATSC HDTV standards and supports 8-channel digital audio, and with 5 Gbps of bandwidth, HDMI can accommodate future enhancements and requirements. Because HDMI was designed specifically for consumer electronics applications, it offers an array of additional consumer enhancements. As digital content can manifest itself in a variety of sizes, resolutions and formats, HDMI-enabled systems will automatically configure to display content in the most effective format. In addition, HDMI enables a single remote point and click, allowing manufacturers to deliver home theater systems that automatically configure from a single command from a remote control -- turning on or off the components necessary to view a DVD, listen to a CD, or watch cable or satellite TV.

HDMI Interface - A Beginner's Guide
by Clint DeBoer

Starting around 2003 we saw a rapid adoption of the Digital Visual Interface (DVI) across the digital consumer market. This included DTVs, high definition set –top boxes and computer graphics boards. By the end of that year, well over 500 consumer electronics products featured a DVI connection, with approximately 80% of DTVs shipped to the US using that technology. Later in the year, HDMI also emerged as a digital transmission format, but addressed some specific needs tailored to the consumer electronics market:

1) HDMI could carry both uncompressed high definition video (with support for SDTV and HDTV color spaces) along with all existing multi-channel audio formats and even device control data in a single connector
2) HDMI offered “link intelligence” enabling devices to automatically “discover” each other and recognize resolutions & formats
3) By design, HDMI was intended to be a smaller, more consumer-friendly connection (we would argue this last point due to lack of strain relief and any mechanism to secure the connection in place)
4) HDMI would be fully compatible with DVI

The HDMI Working Group was announced in April of 2002 and included Hitachi, Panasonic, Silicon Image, Sony, Thomson, and Toshiba. The group’s charter was to define the next-generation digital interface specification for consumer electronics products.

In excess of six million HDMI-enabled consumer electronics devices were shipped in 2004, up from a mere 250,000 in 2003. There are expectations that there will be 125 million HDMI-enabled devices in the market by 2007. According to IDC and Silicon Image estimates, there will be over 15 million HDMI-enabled digital televisions at the end of 2005, growing to nearly 50 million units at the end of 2007.
Specifications, Versions, and Capabilities
HDMI version 1.0 met the goals of the HDMI Working Group and provided a true one-cable solution for uncompressed HD video and multi-channel audio including Dolby Digital and DTS bit streams (more on format support later).
HDMI 1.1 was a relatively minor update. The primary feature was to add some packets of audio-related content protection information. These packets were required by DVD-Audio in order to permit DVD-Audio content transmission on HDMI. HDMI 1.0 had the audio and video bandwidth and capabilities and HDCP already had the content protection capabilities, but there was some data that the DVD-Audio folks wanted to send to HDMI/HDCP sinks to tell them not to send the DVD-Audio content elsewhere.
As for HDMI 1.2, several companies have requested enhancements to the HDMI spec that are being considered by the HDMI Founders, but these items are, by agreement, not permitted to be discussed publicly until the specification is released. The HDMI Founders designed the HDMI specification to be dynamic. As such, HDMI has plenty of extra bandwidth to accommodate future audio and video requirements, and the Founders are committed to evaluating and updating the specification to accommodate new audio and video formats that may be introduced in the foreseeable future.
Let’s Talk Bandwidth
Everyone would agree that if you want the optimal audio and video reproduction quality it is generally best to transfer an uncompressed audio-video stream from the source. Transferring uncompressed audio-video data, however, requires a lot of bandwidth (you’re looking at gigabits per second) over a single cable. Interface standards like IEEE 1394 (400/800 Mbps) transfer only compressed audio-video data, thereby potentially compromising the picture quality.

A single HDMI link, on the other hand, is capable of transferring up to 24 bits of user data at 165 Mpixels per second, resulting in a massive bandwidth of nearly 4 Gbps. This is enough to support the 1080p resolutions of today’s newest high-definition displays while still leaving room to transport up to 8 channels of high-resolution audio with 24 bits of resolution and a sampling frequency up to 192 kHz – all across a single HDMI cable. This is well beyond the maximum specifications of even DVD-Audio, which tops out at 6 channels and a sample rate of 96 kHz. The fact is, the HDMI standard includes extra headroom to allow for future upgrades to audio formats.

TDMS Encoding & Signaling
Like DVI, the HDMI specification is based on TMDS encoding and signaling technology. A TMDS link consists of a single clock channel and three data channels. Eight (8) bits of video data are converted into a 10-bit transition-minimized, DC balanced sequence through the use of an advanced data-encoding algorithm implemented on each of the three data channels. This allows for a very strong transmission, while also minimizing the potential for EMI (electro-magnetic interference) over copper cables. Because of the use of the advanced encoding algorithm, data recovery on the receiving end is very reliable, enabling transmission over fairly long cable runs.

With the exception of the connector itself and the optional control signal, the HDMI physical layer is the same as that for DVI. Compliant DVI sources and displays will be interoperable with HDMI devices through the use of a simple, passive DVI-to-HDMI converter cable or converter. This protects consumers’ investment in DVI-enabled CE products.

With a single-link clock frequency of 165 MHz, all existing HDTV video formats can be readily supported, and there is more than sufficient bandwidth to support future video formats such as 1080p at 60Hz (making HDMI ready for the next-generation video formats that have finally started to emerge in 2005). As with DVI, an optional but rarely used second link can be used to double the bandwidth to support any resolutions above UXGA (162MHz). This second link is only expected to be used in high-resolution PC applications and utilizes a different size connector (we’ll expand on this later).

Supported Color Space and Video Formats
HDMI pixel encoding includes support for RGB 4:4:4 as well as digital TV’s YCbCr 4:4:4 amd YCbCr 4:2:2 color spaces. The two 4:4:4 encoding formats are both 8-bit per component sampling for 24-bit per pixel delivery. The 4:2:2 encoding format uses up to 12-bits per component for greater color depth.

HDMI can support all existing and planned PC or TV video formats. Several formats were specifically established in order to jump-start compatibility between products and media whose resolutions were different:

• SDTV: 720x480i (NTSC), 720x576i (PAL)
• EDTV: 640x480p (VGA), 720x480p (NTSC progressive), 720x576p (PAL progressive)
• HDTV: 1280x720p, 1920x1080i (1920x1080p is supported but was not initially defined when the spec was penned)
All SD formats are available in 4:3 as well as 16:9 aspect ratios while HD formats are available in the 16:9 ratio only

[[XC] leviathan18]

i have the over 200 pages about hdmi if you want it with all the specs but those are the basics so you can choose......

[Serra]

EDIT: I originally read this thread as "Component" instead of "Composite"... so yeah, the difference is night and day. HDMI 0wnz0rz Composite. Feel free to read the rest of what I wrote though :)

Or - how about the quick answer?
(though I'm sure those pages of typing were well worth reading)

I work in a relatively large audio/visual department (actually there right now) when I'm not at school... and I can tell you, the difference depends on your television and the signal you intend to use.

For example, if you were to (somehow) find a VCR that did HDMI output.. you would see no difference over its picture on component (which you also wouldn't find on a VCR...). For standard television signals the difference is also about 0 on any television. DVDs start seeing a bit of an improvement with HDMI cabling over component if you're watching it on something like a high definition plasma or very large DLP.
The only time I have ever really seen a difference is on very large televisions (52"+) and some difference on plasmas coming from a high definition source.

Otherwise the difference is so negligible that if you already have component cables, don't bother.

I suppose I'll add in one little caveat: I have seen these televisions run off a 1080i -> 1080p converter box and there was definitely a noticable difference in the warmth and depth of the picture. Plus HDMI carries hi-grade sound as well, where component gives you nothing.

~ Serra

[Semper Fi]

Levi, you've gone above and beyond my question. I very much appreciate the information you've provided. And thanks, but Ill pass on the 200+ pages of info you have on the matter.

And Serra, you're right, I meant component not composite.

So basically, if Im reading this correctly, I won't see a very noticable and obvious improvement of picture clarity from running an HDMI cable from my DVD to my 51" rear projection SONY HDTV over the component cable that Im using now?

[[XC] leviathan18]

perhaps you wont @ 1080i....

but the future is HDMI has better bandwith so when the 1080p comes more accesible and bigger TV price comes down you should use HDMI

no problem i did all my research long ago for the lcd buyers guide but as you can see is pretty large and there is more concepts about new conector types....

no problem to help a fellow xs member :toast: hope you enjoy your kick ass tv set