DVD resolution is 720 x 480 ??

[siratfus]

I've been doing lots of encoding, not because I know much, but because I simply follow instructions. So there are things that I still don't understand. For example, the tool I use is Nero Recode. I encode all my "main movie" titles into Nero Digital files disregarding menus and all that stuff.

When I load a movie into recode, it automatically configures some of the settings like whether or not to deinterlace, the cropping and resolution. So one thing that I've never understood is the resolution. It always automatically adjust the width resolution to 720, but the height is often adjusted below 480, often times all the way down 368 or something, then it has this Letterboxing (square pixel) box that it automatically checks, which reduces the height resolution further. So at 368, with the Letterboxing check, it goes all the way down to 304. I have the option to custom resize. So my main question is: Shouldn't I resize it to 480 if I want it to fill my screen just exactly the way the original dvd filled the screen? You see, I have not been resizing it to 480, I've always left it at whatever Nero recommends, and my TVIX box has always played the files nicely, filling up the screen more than the original dvd. That's what I don't get. The original dvd that is 720 x 480 vertically fills up less than my nero digital file that's at 720 x 368. How come the 720 x 368 file is vertically covering more area? Shouldn't it be covering less? Shouldn't I see a larger black horizantal bars with my 720 x 368 file?

Can someone explain to me what this all means? I've been doing lots of encoding, but now I'd like to understand it as well. Your time is appreciated.

[yoda313]

It sounds like it might be the aspect ratio you are working with.

Are these ones that go down to 304 movies like Pearl Harbor, Lord Of the Rings, Star Wars?? These big movies use the ratio 2.35:1. That is the really wide black bars on a 4:3 tv. The comedies and other stuff use 1.85:1 and have a small black bar on a 4:3 tv.


Could this be what you are asking? Because the frame of a dvd is 720x480 - that is the dvd spec. All of the other stuff is the formating of the movie whether it's full or widescreen and letterboxed or not (ie fixed frame).

Perhaps others can explain it more precisely but I think I might be getting it in the right direction.

Hope this helps.....

[siratfus]

Hi Yoda, correct me if I'm wrong... So a dvd is 720 x 480. The difference between 480 and 304 is 176. That 176, are those the black bars?

[yoda313]

I don't know 100% since I don't know what the original source is. BUT my suspicion is that you are dealing with the widescreen formatting issues. Yes.

Again I'm not the expert on the precise numbers from the full frame to cropping. But that is what I think you are asking.

[jagabo]

NTSC DVDs are almost always 720x480. Note that this frame size is neither a 4:3 nor a 16:9 ratio. There are flags in DVD data that tell the DVD player whether the image encoded into the 720x480 frame should be displayed as 4:3 or 16:9 on the TV screen. The final shape of the picture on the TV screen is called the Display Aspect Ratio (DAR).

When you create a Nero Digital file it likes to convert to "square pixels". This means that the DAR is the same as the ratio of the frame dimensions.

To make square pixels from 16:9 DVD the 720x480 frame will be reduced to about 720x400. To make a square pixel video from a 4:3 DVD the frame can be stretched to 720x540, or squeezed to 640x480 (or some other 4:3 ratio frame size).

Many (most?) movies are wider than 16:9 (1.777 to 1) and include black bars top and bottom to fill out the 720x480 frame. These black bars are what Nero Digital is cropping away. For example a 2.35 to 1 movie will have a 720x480 frame with the picture filling a ~720x360 portion of the frame and ~60 pixel wide borders top and bottom (360+60+60=480). After resizing the frame (with borders) to 16:9 (~720x400) then cropping away the black borders you will be left with a ~720x304 frame.

Movies come in many different aspect ratios so you will likely see other frame sizes in your final videos. And programs often prefer to encode with frame sizes that are a multiple of 16. They will either crop a few lines off, add a few lines of black, or slightly distort the image to make the frame size a multiple of 16.

[zwatcher]

am i right in assuming your goal is to change the frame height to remove the black bars at top and bottom of screen?
because doing so could have adverse effect on your video
to change the height without changing the width will result in a stretched or distorted picture

[hech54]

am i right in assuming your goal is to change the frame height to remove the black bars at top and bottom of screen?
because doing so could have adverse effect on your video
to change the height without changing the width will result in a stretched or distorted picture

I think 6 YEARS LATER, the original poster has no interest in this....your first post.