David_J

3:2 pulldown driving me nuts

This all seems so complicated. I bought an HDTV the other day and planned to buy a new progressive scan DVD to use with it. I currently have a non-progressive Panny A120. Just as I am doing some research and considering a purchase I am told by a friend that I might not need a progressive DVD in order to watch movies at their best quality because my TV might do the deinterlacing for me instead of having to buy a new DVD player. He said it had something to do with 3:2 pulldown, but after doing a google search I'm still confused as to what I need.

My TV is a Zenith C27V22 and you can see it's specs right here . I don't see anything about 3:2 pulldown and nothing about deinterlacing, but it does say something about ( HD READY - 1080i,480p/line doubler ). Can someone check out those specs and maybe set me straight.

Jack Briggs

The Zenith's internal line doubler may very well provide you with a good progressive-scan picture. But conventional wisdom is that a prog-scan DVD player generally does a better job at deinterlacing than do most displays.

There is nothing in the linked specifications for the Zenith direct-view set to indicate it does 2:3 pulldown correction. And, if it were my money, I'd get a good progressive-scan DVD player that has 2:3 pulldown circuitry.

David_J

Thanks for the info Jack. So the "Line Doubler" in my TV technically does the same thing as a progressive scan DVD player (albeit maybe not as well)?

Is it safe to say that all progressive DVD players have a 3:2 pulldown? I've noticed that some mention it, while others don't. I'm looking at budget player like the JVC XV-N44SL and XV-N55SL. They are both progressive scan, but they make no mention of it in their specs. They list the following:

Would the "theater Position" be referring to 3:2 pulldown?

Thomas Willard

I would not worry too much about whether the DVD player is progressive scan or not. At 27 inches screen size I doubt if you will be able to tell the difference. DVD players do use different chips to produce the 2:3 pulldown with some better than others.

Theater position most likely refers to different color temps. but would not refer to 2:3 pulldown since that is either on or off. If the source material is video then there is no need for 2:3 pulldown. Source material that is filmed (at 24 fps) does need it to compensate for the scanning frequency of 30HZ.

Bob McElfresh

Part of the problem is that the technical-terms get turned into marketing terms and loose their meaning.

Example: A "Progressive Scan" DVD player does not exist. The "Progressive" means that the video lines are sampled/drawn in natural order instead of interlace. "Scan" refers to the scan-lines/electron-beam on your television tube as it 'paints' a picture. But the term "Progressive Scan" has stuck.

Let's try and explain things:


All current HDTV's will take a standard, interlace video signal (called "480i") and do at least 2 things to it:

- De-Interlace the rows of video (make it progressive)
- Do 3:2 pull-down detection/compensation (movies and video have different Frames-Per-Second rates and this is how film is converted to video FPS).

This is also exactly what a Progressive Scan DVD player will do.

So why is a Progressive Scan DVD considered 'better'?

Because the DVD player does all the work with the Digital information straight from the disk so it has better control.

A ordinary DVD player with a HDTV will:

• Read the Digital information from the DVD
• Convert the information to Analog
• Send the video (480i) out the wires to the TV
• The HDTV takes the Analog signal and has to CONVERT it back to digital.
• Use the converted digital information to De-Interlace and do 3:2 pulldown
• CONVERT the digital information to analog for display

See those 2 extra conversions - it's like taking a photo-copy of a page, making another copy from the copy and reading. The "copy of the copy" is readable, but it's not as clear/sharp/clean as the original.

This is why in general, a Progressive-Scan DVD player will do a 'better' job with the same HDTV than a non-progressive unit: the extra conversions are skipped.

Does this help?

Jeremy Scott

my jvc iart 36" HDTV has 3:2 pulldown, i am using a ps2 now with component inputs, is it worth buying a new progressive scan dvd player, like a nice panasonic one?

David_J

Very good explanation my friend. It's greatly appreciated.

I guess that the progressive scan dvd player is the way to go. One question though. Since I haven't gotten the progressive DVD yet will my standard DVD automatically do this for me, or do I have to set somtthing up? When I hook my dvd player to the 1080i/480p HD component input on the back of my TV I get a message telling me to please hook up a compatible source to the input. But when I hook it up to the standard component input it works ok. However there is no way for my to tell weather it's actually doing the doubling. Or does it only do it on the HD port?

On another note, I went to my local adelphia cable office to pay my bill friday and asked about HD. They informed me that they have the boxes, but they are still writing some kind of code and it should be ready next week. I'll try it out and see how I like it. I'm not sure if it will be worth the extra money or how many stations they will have, but I'll try it out for a least a month.

brentl

Your DVD player does NOT do progressive.

The HD input only accepts an HD signal(progressive scan DVD ETC) so that error message is really telling you the obvious .... hook up your current DVD player to a standard component input and the TV will do the Deinterlacing and 2/3 conversion internally.

When you get a Progressive scan DVD hook it up to the HD input.

Brent

seth_petry_john

If you really want to learn about 3:2 pulldown and progressive scan DVD players, there is a very interesting and very complete article on it over at Secrets Of Home Theater High Fidelity:

hometheaterhifi.com/volume_7_4/dvd-benchmark-part-5-progressive-10-2000.html

It took me awhile to get through the whole article, but man was it worth it!

Regards,
Seth

Nick-G

Hey great thread!! I was a bit confused about 3:2 pulldown and progressive scan DVD players. I was also looking at the Zenith C27V22 and was wondering what you think of it??