What is better DVI or Component? Is this a valid comparison? (1 Viewer)

[Ellie Be]

I just decided to get the Sony 60xbr800. I know it comes with DVI which I still don't understand that well. Along with the TV, I want to get a DirectTV HDTV tuner. Is it better to get one that has DVI or will component video work just as well? Thanks for all of your help.

 

[Cees Alons]

Ellie,

Welcome to the forum!

DVI and 'Component' (and also S-VHS) are different ways of representing the whole 3-color image. All three allow the monitor to get the separate colors intact. The only difference between DVI and component is the format: DVI is the format used for PC-monitors. It is independent (in a way) of the TV-formats, such as NTSC or PAL.

So if you don't plan to use PC-type monitors, DVI is rather useless to you. If you think you may use one of those one day, it could be very advantageous.

Cees

 

[BrianEK]

DVI will be a benefit to you in the future. the benefit of DVI over Component video is that DVI is an uncompressed video signal whereas component video is compressed. So ideally DVI will give better quality. As of right now you really wouldn't notice any difference between the two cables, but you will benefit in the long run with DVI. When HD programming becomes more regular they are talking about adding copy protection to the signals from sources such as PPV or premium channels. So if they add copy protection, then you must compress video signal even more to add more information through the cable. So since DVI is uncompressed, you won't have a restricted video quality because of added copy protection signal. plus you can buy a good DVI cable for about the same money you'd spend on a good component cable anyways. So why not!?!

 

[Bob McElfresh]

whereas component video is compressed..

Huh?!? Since when did this happen to an analog signal?

People who have HDTV's and a source with both component and DVI have tried A/B comparison and found little apparent difference. Since few DVD players offer this, there is no easy way to throw up test patterns and do more testing.

Eventually, DVI will be superior because it allows the video signal to remain in a DIGITAL format so the televisions will be able to do the scaling/de-interlacing/3:2 pulldown/etc without converting the analog component video into digital.

 

[BrianEK]

Yes, as I said right now nobody would really notice a difference between signals. I agree with the fact that component video and DVI look too similar to tell apart. and as you said also it allows the signal to remain digital. the same reason now Pioneer has us able to listen to DVD-Audio through a firewire instead of 6 analog cables, so the signal can remain digital. but the other reason DVI is superior is when copy protection is added to HDTV signals (cause we all know that's gonna happen!). The DVI cable allows a larger signal to pass through it (i.e. more information flow at one time). It's like comparing 56k modem bandwith with high speed broadband or T1 connection bandwith. you get more information passed through the cable at one moment in time, resulting in better and faster performance. If more signal can be passed through a cable, no need for compression? Component video has to compress the signal (as well as convert to analog) so when copy protection signal is added, you will then be compressing the video signal even more to make more space available. So hence better picture from a DVI cable. I know nobody can notice a difference right now with the naked eye. but later on "in the long run" DVI is the way to go. Since it has also been determined by all companies making projection TV's except Mitsubishi who is still sticking with firewire.

 

[Doug_H]

Additional here: DVI is required to view the 720p and 1080i via the new DVd players like the Samsung. Because of copyright issues with the various media powers it is quite possible that HDTV via cable and DSS boxes will soon require the DVI port to receive the true HD programming.

DVI will very likely be the best option in the near future.

 

[Bob McElfresh]

Ahhh

When Brian said "component video is compressed", it threw me.

"Compressed" usually means that something took away some information so there is less to transmit. Example: Dolby AC3 is a compression technique that throws away 5/6 of the data compared to say a CD track, but it re-constructs the information at the end so you dont notice the data loss.

Yes, the DVI bandwidth enables it to carry more information than component video. But it brings up other connotations if you described it as 'compressed'.

 

[JohnnyG]

Eventually, DVI will be superior because it allows the video signal to remain in a DIGITAL format so the televisions will be able to do the scaling/de-interlacing/3:2 pulldown/etc without converting the analog component video into digital.

IF the set actually does this. My guess is that virtually every set out there today with DVI input does a D->A conversion right at the input, then feeds the analog video into the TVs existing circuitry...which would then re-digitize it for processing.

This would be the easiest and cheapest way to implement it.

 

[BrianEK]

sorry, didn't mean to confuse people using the word "compressed". yes you will receive full picture quality using component cables, you're not "sizing down" the signal. I just meant that when the industry adds more information the DVI cable will handle all the signal at once without having to "compress". Which might happen to component cause they will be trying to fit more signal through a smaller "bandwith" cable.

 

[JohnnyG]

Sorry Brian, you're still off-base here. My guess is that you're getting confused between DVI and 1394 (Firewire).

You can send the exact same signal down either component video or DVI connection. The DVI signal is digital, the component video signal is analog. That's really the only difference.

The 'nice' thing about digital (as far as 'Hollywood' is concerned, of course) is that you can encrypt the data.

 

[Cees Alons]

'S-VHS' and 'Component' aren't compressed at all. The real difference with DVI is: analogue versus digital. DVI is the latest development (since one or two years) in PC's and especially suited for LCD-monitors and the like because they can use a digital signal to their advantage.

If you have an analogue monitor and the original signal is digital (like on DVD) or if you have a digital monitor and the signal is analogue (like on VHS or standard TV transmissions), there's an extra conversion needed, which will always involve some loss.
Worst case is a double conversion, like when the DVD-player converts its signal to analogue and a circuit of the monitor has to convert it back to digital.

But with the current technological level the image is generally very good in all those cases.


Cees

 

[Thomas&CJ]

What exactly is DVI?? and what do the letters stand for. Thanks.

Tom j.

 

[Kristopher*S]

DVI stands for "Digital Visual Interface" (sometimes "Digital Video Interface") [definition] I'm most familiar with DVI from the computer world where it has quickly become the standard connector used to connect modern video cards to modern displays.

The advantage of DVI over component video in the home theater world is that the signal can remain in it's digital form longer...saving the digital-to-analog conversion until right before the signal is displayed on screen.

For those people out there who can sense a difference between viewing video via a low quality component cable vs. a high quality component cable, then DVI is your holy grail. The visual difference between low quality and high quality component cables is a differenc in the amount of signal degradation. If your signal stays in the digital realm when traveling between components you cut out the factor of signal degradation during the "trip".

I unfortunately haven't had the opportunity to do an A-B comparison between HDTV delivered via component and DVI. But my new set and new HDTV cable box both have DVI, so as soon as I can afford the cable, I'll try it out and report back!

Also, regarding the use of the word "compression" in eariler posts: It should be noted that ALL HDTV signals, no matter how they make it into your home (over the air, satellite, or cable), are both digital and compressed. Once it is converted to analog the term "compression" no longer applies.


- Kris

 

[JohnnyG]

I really doubt you'll see much of a difference. It comes down to which component has the better digital->analog converts in it - the set top box, or the TV.

I calibrate TVs and I don't have anything that will output test signals through DVI, so I have no way of calibrating a TVs DVI input. Just another thing to think about.

 

[Allan Jayne]

One thing you should be aware of: DVI comes in different resolutions such as 720x480, 640x480, (something)x576 (for PAL), 1280x720 (720p), etc. at 50, 60 (59.94), 72 or whatever frames per second. The cable and jacks are the same. You need to make sure your TV accepts the specific resolution that the cable box or DVD player is going to deliver.

You don't want to be stuck with a 480p @ 60 Hz DVI as the only common denominator for your equipment.

In my opinion, good (analog) component video for DVD which is 720x480, is better than DVI at 640x480.

As far as I know, the existing consumer video standards for DVI use the same color space as analog component video, the terminology Y, Cb, Cr is used for the digital form versus Y, Pb, Pr for the analog form.

Video hints:
http://members.aol.com/ajaynejr/video.htm