Why You Should Invest in an Up-Scaling DVD Player

[Jeremy Charette]

So, you just bought an HDTV. You hook it up to your DVD player, get all the aspect ratios sorted out, and it looks great, right? Sure it does, but it could look better. Here's why: your DVD player only outputs a 480p signal. That is, it sends the TV a progressive scan signal that's 640x480 pixels. However, widescreen DVDs are mastered in 720x480 pixel resolution. So your DVD player is down-scaling the signal to fit a 640x480 screen, then the HDTV is up-scaling it to fit a 720p or 1080i/p screen. Much of the original detail is lost in the process. The result: the picture isn't nearly as good as it could be.

But wait! If you buy an up-scaling DVD player, it will take that 720x480 signal, and only up-scale it to 720p or 1080i/p. You won't lose any of the details in the picture, and the TV won't have to scale the signal to fit the screen. You'll see every detail you possibly can. So if you make the plunge and invest in an HDTV, spend another couple hundred bucks and get an up-scaling DVD player. You'll thank me later.

[BugDude10]

I was just reading something about this the other day (maybe on the HDBeat site DMT linked to the other day). Someone asked why you'd buy a $400 DVD player to do the upscaling when your $3,000 HDTV may do it better. (I don't know enough about this issue to answer that question myself.)

[Jeremy Charette]

It's a good question. As previously pointed out, a conventional DVD player has to do some conversion to get the signal to the TV, then the TV has to stretch it back out again. The resulting picture quality isn't nearly as good as what's possible.

An up-converting DVD player doesn't have to go through all of these steps, and preserves the original information stored on the disc. The up-converted picture is much sharper and clearer than the one you'd get out of a conventional DVD player.

It's worth spending a few extra bucks.

One caveat: most up-converting DVD players require you to use the HDMI output, so your TV has to have a DVI or HDMI input to get the best picture.

[Brendan Goetz]

This is very true.

[ianbjor]

So, you just bought an HDTV. You hook it up to your DVD player, get all the aspect ratios sorted out, and it looks great, right? Sure it does, but it could look better. Here's why: your DVD player only outputs a 480p signal. That is, it sends the TV a progressive scan signal that's 640x480 pixels. However, widescreen DVDs are mastered in 720x480 pixel resolution. So your DVD player is down-scaling the signal to fit a 640x480 screen, then the HDTV is up-scaling it to fit a 720p or 1080i/p screen. Much of the original detail is lost in the process. The result: the picture isn't nearly as good as it could be.


This is not true if the DVD is Anamorphic Widescreen (a.k.a. "Enhanced for 16:9 TVs") and you configure the DVD player so it knows you have a widescreen TV. It's getting hard to find Widescreen DVDs that are not Anamorphic anymore.

Your TV won't be displaying an HD signal, but it's not as bad as you describe.

[Jeremy Charette]

Regardless of whether the disc is anamorphic widescreen or not, the picture produced by an up-converting DVD player is significantly better than the picture you'd see from a conventional progressive scan DVD player. In the process of reading the disc and producing a 480p signal, some of the original picture data is lost. Only an up-converting DVD player can reproduce every bit that's on the disc.

From Home Theater Magazine's review of the Bravo D2 (one of the first up-converting DVD players):

"The D2 measured out to the limit of the DVD resolution pattern in title 1, chapter 8 of the Avia Pro test DVD. This test pattern also has a 6.75-megahertz circle in which you'll see blurry patterns and black patches if a player is unable to reproduce the finest details; the D2 rendered this circle perfectly in 720p mode, which is further indication of its outstanding performance through the DVI output."

"OK, so the D2 measures out to DVD's frequency limit in 720p mode. How does that prove that it creates the illusion of greater detail? Well, using the same projector and DVI cable, when I changed the player's output resolution from 720p to 480p, the lines in the Avia Pro 6.75-MHz circle weren't quite as cleanly delineated. With the Video Essentials resolution pattern (title 17, chapter 13), the D2's apparent resolution in 720p mode was perceptibly better than it was in 480p mode. During this test, video editor Geoffrey Morrison commented that it was the first time he'd seen a tangible reason to recommend an upconverting player. The same signal seemed to have better resolution at the 720p setting."

[klinux]

Here's why: your DVD player only outputs a 480p signal. That is, it sends the TV a progressive scan signal that's 640x480 pixels. However, widescreen DVDs are mastered in 720x480 pixel resolution.

Hmm, you have lost me there. I definitely believe if possible, one should get an upconverting DVD player. However, there some technical details may need clarification.

First, you mentioned progressive video is sent by DVD player as if that is true for all DVD players. DVD for US (NTSC) is encoded as 720x480 interlaced MPEG-2 (ITU standard). Only in the late 90's was progressive DVD player introduced commercially for consumer use that can reinterleave the video back to progressive content like films. Otherwise, it is quite possible (and normal) that the DVD outputs an interlaced signal.

Got to go to a meeting but I can recommend this long but very informational read: http://www.dvddemystified.com/dvdfaq.html

[Jeremy Charette]

Sorry, I was making the assumption that if you've invested in an HDTV, you've also probably purchased a progressive scan DVD player in the last couple of years. Even the least expensive DVD players at Wal-Mart are capable of producing a progressive scan signal these days.

That being said, most up-converting DVD players also have specialized circuitry that converts the signal to progressive scan, while also eliminating the jagged edges and artifacts caused by going from interlaced to progressive. Those cheap progressive scan DVD players I just mentioned don't have this ability, and the resulting picture isn't nearly as smooth and clear as it could be.

Just one more reason it's smart to invest those few extra bucks.

[klinux]

Yes, but a whole other debate can start with whether you would want your DVD player to do the upconverting or the TV? I will actually leave that discussion for a later post.

First, you also mentioned your DVD player "send the TV a progressice scan signal that's 640x480 pixels". How do you know that and can you confirm it?

I was under the impression that all NTSC DVD player outputs a 720x480 29.97 fps signal as it is stored on the DVD, and the aspect ratio flag encoded in the MPEG-2 stream tells the TV how to handle it. I think it is technically impossible for any DVD player to output a 640x480 signal.

[Jeremy Charette]

I think the review of the Bravo D2 says it all. You want the up-converting DVD player to handle the scaling, not the TV. For a ton of reasons.