What is the function perform non-square pixel rendering

emdy · Post by **emdy** » Tue Sep 05, 2006 8:59 am

What is the function perform non-square pixel rendering and perform auto-deinterlace during make rendering

Terry Stetler · Post by **Terry Stetler** » Tue Sep 05, 2006 6:53 pm

Book definition:

Perform non-square pixel rendering performs non-square pixel rendering when previewing your video. Non-square pixel support helps avoid distortion and keeps the real resolution of DV and MPEG2 content. Generally, the square pixel is suited for the aspect ratio of computer monitors while the non-square pixel is best used for viewing

Mostly I find non-square pixel rendering helps when mixing aspect ratios on the same timeline, video or image, but you also have to set the Preferences default aspect ratio to use that of the source.

Auto deinterlace is used when you have Interlaced sources in a Frame (progressive scan) project.

Devil · Post by **Devil** » Wed Sep 06, 2006 7:45 am

I'd add that in PAL-land, use square throughout. 768 x 576 is 4:3 and this is the native pic size, even if you are using 720 or 704 pixels-wide or anamorphic 16:9 (or letterboxed).

Helge · Post by **Helge** » Fri Sep 15, 2006 7:40 pm

Even so I know what square and non square pixels are, I have to admit that I allways wondered in which situations it makes really a difference. I belief that in most cases there are only calculations (like adding or replacing the value) of pixels with same x/y coordinates and different tracks. So it should not matter if the pixels are qudratic or not.

Situations where I think it could be important are:
Moving paths (e.g. a 45° degree will be different)
Converting images (or videos) with different resolution than the output resolution.

But I wanted that Ulead would give much better explanations for all controls and options of their programms. At least as online manual. First step could be that Ulead would provide a book like "getting results" with msp. But even this would still lack a lot of technical background.
For the non-square-rendering-option I would like to see something like rastered images with a few colored dots, a filter or moving path or what ever and explanation of different results.

And the explanation of the mpeg rendering options could fill a book alone

Terry Stetler · Post by **Terry Stetler** » Fri Sep 15, 2006 11:47 pm

The link below is a zipped PDF documenting the settings in the full MainConcept encoder. The arrangement is a bit different, but it's very close to Uleads Advanced MPEG menu since both use the MainConcept encoder SDK;

http://digitalvideo.8m.net/mc-adv-doc.zip (432k)

sjj1805 · Post by **sjj1805** » Sat Sep 16, 2006 12:02 am

A picture tells a thousand words.
The following screen shots are of the same 720 x 576 picture.
Using Adobe Photoshop you are able to choose the Pixel Aspect Ratio
the top picture is with Square pixels selected. The bottom picture is non square.

When you check Image | image size - both are shown to have the same 720 x 576 dimensions.

DarrenD · Post by **DarrenD** » Sat Sep 16, 2006 12:45 pm

Have a look at my posts here about 2 years ago http://forums.murc.ws/showthread.php?t= ... ight=pixel

Helge · Post by **Helge** » Sun Sep 17, 2006 7:51 pm

Terry:
Thanks much for the link! (In fact I knew most of the settings from books about compression technic and so on. But other users might not know it, so for them ists a great help.) But isn´t it a shame for Ulead, that we need to read manuals from other companies to be able to work with Ulead programs?

Steve:
Sorry, but your pictures dont really explain the option. What you showed is, that non square pixels will stretch the image when displayed. I think that is clear for everybody(

). But it is not obvious if it makes any difference selecting the non-square-pixel-option if I have a 720 x 576 input video and render that to a 720 x 576 output video. I have no idea which formulas or calculations are affected. Despite that it is prohibited by the license agreement I am not interested in decompiling / disassembling msp to figure it out.

I usually set the option even so I am not sure that its really necessary.
But I would much prefer a clear documentaiton form Ulead.

Terry Stetler · Post by **Terry Stetler** » Sun Sep 17, 2006 9:47 pm

I agree it would be nice if Ulead updated that PDF with their UI images and posted it to their site, but since it's MainConcepts media and therefore copyrighted....

Jerry Jones · Post by **Jerry Jones** » Mon Sep 18, 2006 6:50 am

There are two types of pixels.

1. DV utilizes RECTANGULAR pixels (720 x 480).

2. Graphics programs use SQUARE pixels.

This can affect the appearance of circular shapes created in graphics programs.

Try using any image editing program to create a CIRCLE.

If you use any square-pixel computer graphics program to create a 720 x 480 frame that contains a CIRCLE shape, you will be surprised when you import the image into your video editing program and then render it out.

When you render the image to be video, the CIRCLE's shape will no longer be perfectly CIRCULAR; it will instead appear "EGGULAR."

This is why many people who create graphics use the 768 x 576 frame size to compensate for DV's rectangular pixels.

This is also why 4:3 aspect ratio DVD menus are not 720 x 480, but instead are 768 x 576.

Hope this helps,

Jerry Jones
http://www.jonesgroup.net