dvd-hq.info Forum Index dvd-hq.info
DVD & video forums
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Which DVDs are interlaced?

 
Post new topic   Reply to topic    dvd-hq.info Forum Index -> General
View previous topic :: View next topic  
Author Message
Grand Dizzy



Joined: 11 Dec 2004
Posts: 2

PostPosted: Sat 11 Dec 2004, 1:04    Post subject: Which DVDs are interlaced? Reply with quote

Sorry if this isn't the right place to ask, but I just wanted to know which DVDs are interlaced. I'm buying a progressive scan TV and I don't want any interlaced signals how do I know which DVDs are interlaced and which aren't? Or all they all interlaced?

And also, can anyone explain how an interlaced signal is encoded onto a DVD? I thought mpeg files were slightly blurry (for the sake of compression). If they are slightly blurry, then how can the crisp, sharp lines of the interlaced signal be preserved? And if the two fields bleed into each other then won't the motion look blurry?

Major confusion, here!

Please could someone help!
Back to top
View user's profile Send private message
RMN
Site Admin


Joined: 04 Feb 2003
Posts: 587
Location: Lisboa, Portugal

PostPosted: Sun 12 Dec 2004, 3:35    Post subject: Reply with quote

No, MPEG is not blurry unless you use a very low bitrate, but even if you do blur an interlaced image, it will still play correctly, because the two fields are likely to be very similar anyway (in fact, if an image is too sharp, like some computer-generated images, small details may "flash" when shown on an interlaced monitor). Blur them by about 0.4 pixels and they will look much better. It doesn't actually look blurry unless things are blurred by 1.5 pixels or more.

Regarding interlaced DVDs, there's no way to tell. If a DVD is made from video (ex., some TV series, some documentaries, etc.), it's likely to be interlaced.

If a DVD is made from film, it can be interlaced or not. PAL "film" DVDs are almost never interlaced (they simply play back at 25 fps instead of the film's 24 - that's why PAL versions are usually 4% shorter than NTSC versions). NTSC "film" DVDs can be interlaced or not. If they're not, it's up to the player to apply pulldown (convert each frame to 2 or 3 fields, alternately) when it's connected to an interlaced TV.

But you can get a progressive signal out of an interlaced DVD anyway (the player just needs to apply pullup to recover the original frames), so there's no need to worry about that. The only disadvantage of interlaced DVDs is the video files are a bit bigger (because they're 29.97 fps instead of 24) - the image itself is virtually identical.

One advantage of PAL DVDs is they have 20% better vertical resolution, but you need a TV that can handle the PAL signal.

RMN
~~~
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    dvd-hq.info Forum Index -> General All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum



Powered by phpBB © 2001, 2002 phpBB Group