Changing aspect ratio. Does it distort the image?

[zavar]

This pertains to making a DVD backup. If I change the aspect ratio of a 16:9 movie to 4:3 with IfoEdit, will the resulting image be distorted in any way?

[chilled]

I dont know the exact answer, but common sense says that image will either be distorted or cut, so you will loose anyway IMHO you should keep original AR.

[jggimi]

Let's level set on DVD video streams for a moment. DVD resolution -- full D1 -- is 720x575 PAL, or 720x480 NTSC. This resolution stays constant, regardless of the Display Aspect Ratio setting, which will be either 4:3 or 16:9.

Changing the DAR will not effect the stored images. It will only effect how your player shapes the video output. You'll have "squished" images.

If your objective is to "convert" a widescreen DVD to a fullscreen DVD, you'll have to do much more than alter a DAR flag. You'll need to edit the images frame by frame, and re-encode.

The method used by production companies is called Pan & Scan. See www.widescreen.org for a discussion of the process, and in particular, this example (http://www.widescreen.org/examples/lord_rings_rotk/index.shtml) of the choices made by the production company to produce a Pan & Scan version.

[smiller667]

Nothing to add to jggimis posting.

Regarding ifoedit: note that editing the DAR in ifoedit alone won't necessarily change anything on screen. Many standalones rely on the header information stored in the actual vobs to determine the DAR. You can change that information using software like dvdpatcher.

[zavar]

Thank you for the very informative answers.