Preventing Distortion of Menu Background Images and Videos

[ckhouston]

UPDATE: 16:9 menu capability was added in CX2D version 4.1.13.356, versions before that could only generate 4:3 menus which require special considerations in some cases that are not covered here. Now menus are generated in the same aspect as that which the last titleset in a project will be converted to in v4, v5 generates menus in the same aspect as the first titleset. So menu backgrounds for the latest versions should generally be prepared with the same aspect as the generated menu.

Introduction

The current versions of CX2D will use all of any image or video used as a background. In other words, it will not crop any part of it as it did at times in the past in order to produce the correct menu aspect. That means that your background image or video should have the same aspect as the menu will be generated in.


How to Prepare Images and Videos for Backgrounds

Images and videos that do not already have the desired 4:3 or 16:9 aspect ratio should be altered before using them.

Still images should normally be cropped in a graphics editor to the desired aspect ratio - number of horizontal pixels divided by vertical pixels. Don't worry about the resolution of the cropped image (CX2D will resize it as needed) but the higher the better usually. Simply changing pixel dimensions (resizing) to change aspect will usually introduce distortion. Changing canvas size to the desired aspect can also be advantageous in some cases if you understand the concept and have an editor with that capability. That method will either crop part of the picture and/or add colored borders.

Changing the aspect of videos to use as backgrounds is a little more trouble because it is done by resizing in a program such as CX2D. You can cut short segments (make them at least as long as menu duration time) from long videos using an appropriate video editor in order to save time and then convert them beforehand to prepare them for background use.

Use any resize method except Stretch, but I prefer to eliminate the clutter of black bars. If your source does not already have black bars, you can do that by setting the converted aspect to what you want and then set the resize method to Pan-Scan. If your source already has black bars , you will have to eliminate them manually in the video resize editor. Equations are given in Calculating Crop/Pad Values for the Video Resize Editor in this forum that will help maintain the aspect ratio -- prevent distortion -- when doing manual resizing.

You can then use the VIDEO_TS.IFO from this mini conversion as the background for your main conversion.

[Claire]

16:9 menu support feature request:
http://bugs.vso-software.fr/view.php?id=3104

[Tyrone Shulace]

Greetings to all!

There is a way to change the aspect ratio (AR) of a menu from 4:3 to 16:9 so that a 16:9 background picture or video can be used without distortion or the need to crop, pad, or edit the picture or video. I have made a PDF file explaining how. Since PDF files can't be posted in this forum, Claire has very kindly uploaded it to a VSO server and allowed me access to post the link to it here. Many thanks, Claire.

Here is the link:

http://oasis.vso-software.fr/Guides/Ran ... enu-AR.pdf

Although the file is 12 pages long, there is a lot of blank space in it because it was formatted to avoid splitting a picture up across two pages. So it's not really as long as it seems.

If you don't happen to have a PDF reader installed on your computer, here's a link to the download page of the free Adobe PDF Reader:

http://get.adobe.com/reader/

Regards,

[ckhouston]

A good easy to follow guide for changing the menu aspect ratio in the IFO files so a menu generated at 4:3 aspect displays at 16:9. The technique has been discussed several times, most recently in http://forums.vso-software.fr/menu-sizi ... 11541.html

But

There is a way to change the aspect ratio (AR) of a menu from 4:3 to 16:9 so that a 16:9 background picture or video can be used without distortion or the need to crop, pad, or edit the picture or video.

The background does have to have a 16:9 = 1.778 aspect though or distortion will be introduced, there is no way around that.

A snapshot of a menu using a 2.25 AR background and with the aspect changed to 16:9 in the IFO, is shown below. Note that the menu does display in 16:9, but the rectangle and ellipses in the midlle are supposed to be a square and circles as shown in the small thumbnail at upper left. Preparing the background, as discussed in the first post above, so it has a 16:9 aspect, will prevent that distortion.

Changing the menu AR in the IFO is sufficient for many standalone DVD players, but may not be enough for some as pointed out by toaddub in the above thread link.

[Tyrone Shulace]

A good easy to follow guide for changing the menu aspect ratio in the IFO files so a menu generated at 4:3 aspect displays at 16:9.

Thanks, glad you liked the guide.

The background does have to have a 16:9 = 1.778 aspect though or distortion will be introduced, there is no way around that.

Yes, I was referring only to using pics or videos that are in 16:9 AR to begin with. Using a pic with a wider AR (such as 2.25:1) and forcing it to fill out a 16:9 AR will indeed cause distortion. In a situation like that, I would add appropriate padding to the picture on the top & bottom so that with the padding included the pic is now 16:9 and has a letterboxed appearance (see attachment below).

There are several ways the correct padding could be added. One way would be to use slideshow generating software that allows you to choose the AR of the output (that's what I did here for the screenshot below). Just make it a one picture slideshow (or repeat the same picture a few times if necessary). If you can do this, there won't even be a need to figure the correct padding, the software will automatically do that for you. After the slideshow is output, take a vidcap of one frame and you now have your original picture with the correct padding added.

Regards,

[ckhouston]

How you make your background AR = 16:9 depends on preferences, programs you have and what you are comfortable doing.

It is simpler for me to use a graphics editor for still image backgrounds -- there are several good free ones including VSO's Image Resizer. I usually crop the image to 16:9 as shown in the attached screenshot to eliminate the clutter of black bars. But you can also use an editor to letterbox the image with black bars, as you did, by pasting the image into a new black, or any other color, background (new canvas) that is sized at 16:9.

Preparation of video backgrounds is discussed in the first post above.

[ckhouston]

16:9 menu capability was added in ver 4.1.13.356. The first post above has been modified to include that capability.