Aspect Ratio problem

[avig70]

Hello

I have yet another problem encoding Israely DVD titles.

besides the fact that they are terebly interlaced in some parts and progressive on other parts, which decomb handles the interlaced parts very well, encoding it in the original resolution 720 x 576 gives a result of a movie with the wrong aspect ratio.

When I open the .VOB files in WMP I have a resolution of 768 x 576 ( I built a special tool for that ), the aspect ratio is just fine.

I don't know where the problem is ?? no matter how I open the files, virtualDub Gordian Knot or any other encoder I still get the wrong aspect ratio.

I can resize it back to the original dimensions but that's the wrong way to do things.

Please HELP...

dakos

[manono]

Hi-

I was going to suggest GKnot, but then you said you had tried it without success. But GKnot does not give incorrect AR, so you're doing something wrong.

So, open the .d2v in GKnot, choose PAL or NTSC, choose 16:9 or 4:3 (from DVD2AVI), tick Pixel and crop the black bars, choose resolution, pick one of the Smart Crops and that's it. Up in the View button, choose Resize and scroll your movie and it should look OK. You sure you did it this way?

[avig70]

I tried it once more just for the heck of it.

Its already destorted when I open it in the preview window so there's no sence in encoding it again.

Could it be that the wrong data in the DVD or MPEG stream is affecting how it is opened in tiffernt programs and if so how do I correct this problem ?

thanks
dakos

[hakko504]

First read this. (1 and 1a is very useful) (http://forum.doom9.org/forum-rules.htm)

You are not the first one to be confused by this question and an answer can be found here! (http://www.doom9.org/aspectratios.htm)

[avig70]

I got the picture.

But isn't there a way to do the same with virtualDub as in Tmpgenc by now ?

What I understood from the article is that the horizontal lines are somehow sqweezed in some sort of mathematical algorithm, to give with the proper player (PowerDVD supports that) the original size\aspect ratio while retaining the quality of the original stream.

Its not a simple resizing function of some sort ?

thank you

[avih]

i think i had once a similar problem. it turned out my direct show mpeg2 decoder output the video at a fixed frame size.

i suggest that u try different mpeg2 directshow decoders.

u may find some on www.vcdhelp.com, go to "toold" menu. u may also find mpeg2 decoders on other places, some of them are free.

cheers
avi.

[avig70]

Hello again

The problem like I saied before is not in watching the movie on my computer because PowerDVD seems to handle that just fine, the problem is with encoding the movie and as far as I know directShow is not involved in that proccess.

I've just looked into a few anamorphic scaling algorithms, the onse that are supposed to be used in the scaling of DVD titles to solve exactly that problem, it looks like they do pretty much the same job as our good old virtualDub resizers.

So I guess the solution to my problem after all is to resize the movie back to its original size unless someone knows that there is a data compression algorithm involved in the proccess of anamorphic scaling after all.

dakos

[manono]

I don't know why you're making it so hard on yourself-just use GKnot. This is not rocket science.

[avig70]

I'm about to encode about 30 titles, which all have the same problems and I wanted to know how to do things the correct way.