DVI for HD cable or DVD player? - Axiom Message Boards

I have to choose between using my DVI connection on my Samsung HDTV for the DVD player or for my comcast HD cable box. The other gets component video. I have a 30" Samsung HDTV monitor and the Samsung HD 841 DVD. My guess is that I should connect the TV to the DVD and use component video between the HD cable box and the TV. Any suggestions?

the 841 will not upconvert over component, so I would use the DVI cable for the DVD Player so you can get 720P or 1080i conversion of your DVD's. I use component on my Samsung HD Over The Air receiver and get 720 or 1080i perfectly on my Toshiba HD ready Flat television.

Or you could invest in a DVI switch and use the DVI connection on both sources.

Scott

Hi Burundanga,

Try the component video with the Samsung 841 and compare the results with the DVI connector. Your Samsung HDTV's internal A/D video processor may deliver a sharper image using the component-video feed than the DVI connection will yield.

It depends on the quality of the video processing chips in both your Samsung HD set and in the 841 DVD player. A friend of mine (Al Griffin) who does the video tests for Sound&Vision magazine found that the 841's DVI output "provides a soft picture and limits shadow detail". In his tests, the 841's analog component video outputs gave better results.

Watch for a feature article on analog and digital video cable links in the Axiom AudioFile newsletter, to be published next Tuesday. You can sign up to receive it on the Axiom home page.

Regards,

Is there any truth to the idea that since the output from the tuner box is TRUE high def, not just "upsampled" from regular definition, that you should preserve that last bit of quality by using the digital connection, or in the real world is that not a factor?

Sory if I'm asking "preliminary" questions to your upcoming article, Alan!

That's what I heard too, Mark, though I can in no way confirm that it's true. Sounds good, though, don't it.

Mark, Ajax,

The theory sounds great, but even when you use a DVI or HDMI connection, the HD set's video processor still has to re-clock the digital video so that it "fits" the set's native resolution exactly. This brings into play the quality of the video processors in the HD set (and other factors that you'll read about). I can't go into it all here.

Turns out it isn't just a simple digital-to-digital transfer of video data. There is also a HDCP encryption code that has to be pulled out of a DVI or HDMI connection--so lots of digital processing that's unconnected to picture quality; indeed it may degrade picture quality compared to analog component video, which bypasses all the encryption garbage. There, now I've given it all away. So a DVI or HDMI may provide better picture quality, or it may not. At least you can try both analog and digital video links and compare the results.

Regards,

Alan wrote:

In reply to:
even when you use a DVI or HDMI connection, the HD set's video processor still has to re-clock the digital video so that it "fits" the set's native resolution exactly.

Interesting.

I had assumed that, for instance, when I choose the 720P output from my cable boxs' DVI connection into my native 720P Samsung, the TV would recognize the signal as already being an appropriate resolution and provide no further processing...

B, welcome. The review by Al Griffin which Alan mentioned is in the new January S&V and you might want to take a look at it. The full text isn't online, but here's lab results with a brief comment on the component connection doing better than the DVI. This is another illustration of the point that theoretical advantages don't necessarily bring actual audible or visible advantages.