Any Video Converter Pro distortion

I'm trying to burn a number of YouTube videos(15, to be exact)to DVD using Any Video Converter Pro. Most of the clips are in the original MP4 format but there are a few which I've converted to high quality AVI after editing with Windows Movie Maker. There are a mixture of 16:9 and 4:3 aspect ratios, which I'd like to maintain. I don't care about black bars, I just don't want any distortion of the videos. So far, whether I burn using the default options under Video Resizing of "fit to width" and "expand to frame" size, or whether I burn with both unchecked, the images in the avi files, in particular, are getting severely fattened. The strange thing is that if I burn any one of the avi files singly to a rewritable CD in order to test it, it looks fine, but when I burn all the files to DVD, the avi's get bloated. Can anyone explain to me the exact meaning and effect of those options, "fit to width" and "expand to size", or tell me how to get all those videos reproduced on DVD with their original aspect ratios and without distortion?
I've converted all the avi files to mpg and mp4 and I can try again with those formats, but I've already spent so many hours failing that I feel like I'm just stumbling around in the dark with the AVC options.

 

The problem is that the software can only guess at the aspect ratio because the videos all have the same 1:1 pixel aspect.
When you merge the files and select a DVD compliant format it picks one AR - can only have one aspect ratio in one title - OTOH you could have multiple titles and they would show correct - except that there is a slight pause as the laser moves from one title to the next during playback - that's what I would do.

The way around it is to ensure that say the 4:3 files end up with a resolution that is around 1.77 aspect ratio;the software then assumes it's widescreen and encodes properly.
To do that you have to process them in the likes of VirtualDub by resizing then applying a canvas resize filter.
The video retains it's original ratio inside the canvas.

 

I guess I should have made it clear that I am burning each of the videos as a separate chapter, not merging them (although one of the files does consist of two merged files). That's what makes the problem so perplexing. I've been working on this project so long and done so much editing of some of some of the files that I may have chosen formatting options somewhere along the line that have somehow corrupted the files. (I will confess, for example, that I've used both AVC and Format Factory, depending on whim,to convert files to avi so that they can be imported into Windows Movie Maker.) My only recourse may be to start over, keeping a log next time of exactly what I've done. The fact that I can burn any one of the avi files alone to a CDRW and have it come out perfectly makes me think that, in this case, mixing the formats is somehow causing the problem, although I've mixed formats in the past with no trouble. Let me ask a question about Windows Movie Maker. Can I assume that when I use it to edit and save a file, I should set that program to use the original aspect ratio? I might have made a mistake there at some point, although the saved videos display perfectly until they're burned to DVD.
I should mention that the type of editing that I've done with Windows Movie Maker consists of nothing more than trimming and transition effects--freeze-frame, fade-out, etc.

I'd still like to get clear on exactly what the options "fit to width" and "expand to frame size" do.

 

Sorry, I've never used Windows Movie Maker.

I'm confused.
What are the files that appear incorrect on the burned disk:are they avi, mpeg or vob?

 

I'm getting a little more confused, myself. I just looked at all the videos on the DVD systematically. Of the fifteen files I've burned, four are avi, the rest mp4. Four of the videos, in total, are "bloated", or stretched, so that everyone looks like Humpty Dumpty, but only three of those are avi(one avi is fine). The other distorted one is an mp4. All of the distorted avi clips have been edited in Windows Movie Maker, but not the mp4, which is as downloaded from YouTube(I think!). I'm thinking more and more that there may be a problem with the structure of those files I've edited (even though they're not the only ones I have edited). Even though I did nothing to the one distorted mp4, it might have been affected by something in the bad ones.

Another possible issue is that I've worked on some of the videos on my wife's computer, which is much better that mine, and I saved some of the files as very high quality with Windows Movie Maker 2012. The resolution of those files is so high that they won't even play properly on my old XP machine, and Media Player Classic frequently crashes when I try. Although those aren't the files that are getting distorted, I suspect that they could have something to with it. All in all, I think I should start over.

 

It may be that the media player on the PC is just not displaying the aspect ratio properly.
I think you would be ahead to forget Any Video Converter and instead take the AVI/mp4 files and load them into AVStoDVD.
It will convert each source file to a DVD Title (it's very good at figuring out the correct aspect ratio) and output them to a DVD folder.
You can play it back on the PC and if it meets requirements, burn it.

The older FAVC program is also good.

 

I have tried playback on a couple of computers with the same result(unfortunately, I don't have a stand alone DVD player to try).
I have used FAVC extensively for burning large videos and have gotten very good results with it, but it's menu options are limited.
I may well try AVStoDVD(nothing to lose)but I'm pretty well firmed up on my plan now to start my project over with AVC. The fact is that I've been working on it for quite awhile and originally was able to burn multiple files with no problem. I kept adding files I decided I wanted and kept editing individual files until, quite recently, the trouble started. That's what makes me think I committed a fatal error at some point. Burning one DVD after another is expensive and very time consuming on my old computer, but I'm afraid I've gotten a little obsessed with it.
I think I should probably thank you, attar, for your help and beg out of the discussion, but I still do have one question: Can anyone tell me the exact effect of the AVC settings, "fit to width" and "expand to frame size"? They might seem self-explanatory but they really aren't.