DVD--> AVI with VirtualDub problem

[aldaco12]

Hi. I already posted my question in "AVISynth Usage" section, http://forum.doom9.org/showthread.php?p=926291#post926291 , but maybe this is the best plece to make it.
Can I ask the same thig to you, too?

I'll repeat again to avoid forcing you to jump there.

Please forgive me to having double posted. :o

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from http://forum.doom9.org/showthread.php?p=926291#post926291

Hi. I'm using AviSynth to 'teach' VirtualDub how to load D2V files, so I can

1) rip a DVD
2) use AVI2DVD to make a D2V file
3) load with VirtualDub the file 'LoadD2V.avs', which is written:

MPEG2Dec3dg_mpeg2source("C:\mc\Tmp\mov\dvd\Movie.d2v")
ConvertToYUY2()

wehere I use Donald Graft's version of MPEG2DEC3.dll placed in AVISynth plugins directory, so I can create an AVI using VirtualDub; I apply the filters:
- Deinterlace, to deinterlace the video
- Nulll Transform + 'cropping', to set some positive offsets and to crop the black bars, if needed
- Resize, to resize the movie screen wich results from the use of the 2 filters above mentioned into a more appropriate size.

The result of all this is that the AVI obtain is somewhat 'stratched', so its shapes are more 'oval' than 'round' (an O becomes an oval a little tall).

It is very strange, to me, since my use of the filter Resize is to produce a movie of resolution:
X' = constant * (720 - cropE - cropW)
Y' = constant * (576 - cropN - cropS)
(I live in a PAL country, and DVD specs are 720x576)
Obviously, "constant" is a constant, and the numbers I use as "cropX" are the pixels I crop when I use the Null transform filter to remove the black bars.

Why the screen seem a little taller than what it should be even if y use of the filter "Resize" should keep aspect ratio? Is it a wrong usage of AviSynth? Is MPEG2Dec3dg buggy?

Thanks for helping me.

[Guest]

Please forgive me to having double posted. The correct thing to do if you think you've chosen the wrong forum is to ask a mod to move it. You may not double post like this.

[wonkey_monkey]

How little is "a little taller"? Either you've got anamorphic video, or you've just discovered that that MPEG2's pixels aren't square (but VirtualDub displays them as square, by default). Try right-clicking on either pane of Virtualdub and select either 16:9 frame (wide) or 4:3 frame (TV). Do either of those look more natural?

ETA: I may have read your post a little too quickly - can you elaborate on how much you cropped and what you resized to?

David

[aldaco12]

When I right-click on VirtualDub's pane and I select
Apect Ratio = 16:9 (WIDE) (as I saw when I extract the D2V with DVD2AVI) I see the screen more natural.
But now? What should I do to make the AVI to seem more natural if watched on a TV?
Is this automatically done by the DVD player depending n which TV it is linked to?

[aldaco12]

OK. I have seen that if I tell the PC player that the aspect ratio is 16:9 the movie is perfect.
But if I play the DivX movie on my TV, it is again 'a little tall' like if I watch the AVI on 1:1 aspect ratio.
How can I correct this to the movie I have already done (if possible) and, at least on the future, on the movie I'll do?
Is it using VirtualDub to encode the AVI a wrong measure, since it produces movie with square pixels?
I never found that such problem existed, on the net!

[wonkey_monkey]

Try reducing the height of your image to 0.6875 - so if it's 432 pixels after cropping, reduce it to 432*0.6875=297 pixels (you may have to round it to an even number for DIVX).

Your original DVD is anamorphic (stretched to improve vertical resolution - automatically squished on playback).

David