Having a problem with image ghosting

[TheronnightStar]

First let me say, I did try to search for this before I posted, but either because I am using the wrong terms or what not I couldn't find anything about it. I am using avidemux to convert some of the anime I have on my comp to DVD to try and free up some space on my drives. My TV has horrible overscan ( ~10% - gotta love wally world ) so I resize the video down to whatever 10% ( 720-72 or 480-48 ) will keep the aspect ratio intact. I then add black bars to fill out to 720x480. I have been doing this now for a bit with Blood+ and everything works peachy.

When I went to try and get the Inuyasha movies off I ran into a problem. The original AVI is 800x480. Using the MPlayer resize filter I resize it to 648x346. All 3 resize types ( bilinear, bicubic, lanczos3 ) produce a good image. The problem is when I add the black bars. As soon as I do that, the image ghosts itself from both edges of the screen. For example, say there is a sphere in the center of the screen, the ghost image will place itself so that half of the sphere is on one edge and the other half is on the other. The entire things shifts itself exactly half way across the screen and wraps.

I've tried nearly all the filters I can find that would deal with anything like that, chroma shift and luma shift and the like. The highest the filters go up to is +/- 32. If I could get it to go up to say 64 or so it might fix it. Seeing as I have tried but failed to grasp avisynth scripting, I am at a loss. Any help solving this would be greatly appreciated.

Thanks in advance
DN

[Midzuki]

Hi there;

If I were you, I would resize to 630x336 by using Lanczos4
( note that 630 == 560*1.125, and 720/640 == 1.125 ).
I presume there exists some colorspace issue that affects
your attempts to resize // add black borders to your video.
For example, if you were using Avisynth, you would have
to change the colorspace of the video to RGB before resizing
to a non-mod(4) width. HTH.

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[TheronnightStar]

I just found a nice little play toy that should massively help me with the whole avisynth scripting. AVSEdit. Seems I have been in the dark about this for a long time. I will most definitely take your suggestion under advisement though. I will make sure to try it and see if it works. The avidemux I was using did not offer Lanczos4 resizing or changing the colorspace to my knowledge. Thanks again.

DN

P.S. Out of curiosity, where did you get the 560?

[Midzuki]

P.S. Out of curiosity, where did you get the 560?

800/480 == 5/3, correct? I choose 560 instead of 576 because
560 is an integer multiple of 5, and in the same way,
336 is preferable to 345.6

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[TheronnightStar]

I found out the problem. Windows is good for something I suppose. My linux avidemux is where I was having the problem. I use it because I have found that on successive encodes my windows version skips chunks of video. When I tried my filters on the windows version it popped an error message, whereas my linux version did not. Seems the AddBlackBars filter only accepts even numbers. I was using 67 on each side to center the video. I changed to 66/68 and guess what, no ghosting. Such a simple answer.

Thanks anyways
DN

P.S. would using the dimensions you mentioned create a better video? I am not to heavy in the math to understand the algorithmic equations used in the resizing process. If I used a base 5 or base 4 dimension would it simply have to remove pixels vs. blending them? ( kinda like the reverse of pulldown, only not with frames - hope you understand what I mean )

[Midzuki]

We all thank you very much for sharing your experiences ---
so that everyone can benefit.

P.S. would using the dimensions you mentioned create a better video?

I still believe so. At least my eyes do perceive the difference
between an exact resizing and an approximate one.

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[manono]

There's a lot screwy about the figures you've put out. You said the source AVI is 800x480. That's 1.67:1. This is an anime, and there simply aren't any anime at that ratio, as far as I know. So, whoever made it didn't know what he was doing. From somewhere you came up with 648x346, which is about 1.87:1, not at all like the original, although maybe closer to what it's supposed to be. I don't know what these movies are supposed to be at, 1.85:1, maybe? Anyway, you can't just pull numbers out of the air. Use FitCD to get the crop, resize, and addborders figures. In this case you have to guess a little bit about what it's really supposed to be. You probably know better than I. To make it 1.85:1 with black borders, I get something like this:

LanczosResize(672,432)
AddBorders(24,24,24,24)

And then encode for 16:9 for DVD. And if I'm understanding your method correctly, you haven't been keeping the AR, and you need a better method. Use FitCD. Here's a guide:

https://forum.videohelp.com/topic296341.html#1487285

[Midzuki]

Considering what manono-sama has just said,
I suppose the OP has gotten a cropped version of
the original video source. Not uncommon, I must stress

From somewhere you came up with 648x346,

Assuming square pixels and AR=4:3, then:

800x480 == 576x345.6 inside 640x480 == 648x345.6 inside 720x480.

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[manono]

I suppose the OP has gotten a cropped version of
the original video source. Not uncommon, I must stress

Really? I wouldn't know. I was figuring it hadn't been cropped, but just resized incorrectly, giving the AVI bad AR. With animation it might be hard to tell it's off. If he went and found something round, and it turned out to be oval shaped, that would be a tipoff.

If it had been cropped, then my figures are wrong, if he wants to keep it at that 1.67:1 ratio. Hard to tell sometimes what you're supposed to do with downloaded garbage.

[Midzuki]

manono wrote:

Hard to tell sometimes what you're supposed to do with downloaded garbage.

I know the problem well! ^.^;;

P.S.: Baldrick should have already added a "sweatdrops" to the emoticon list.

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