Pixel Aspect Ratio help please

[sarahjh69]

I have been using Xmpeg to encode movies
and as the op was always intended for tv use 1:1 pixel ar

Now I have got hold of a Buffy the Vampire Slayer DVD
Pal 4:3 interlaced

I have tried 1:1 and the result seems a bit tall and thin
Why should I be using PAL 4:3 for my AR now ?????

Is it because the source was always intended for TV
please advise me on this????????

[manono]

Hi-

Why should I be using PAL 4:3 for my AR now ?????

Because that's the DAR (display aspect ratio) of the DVD. You get that information from DVD2AVI, and plug it into GKnot when cropping and resizing. For more on the subject, you might want to read Doom9's article named Aspect Ratios Explained (http://www.doom9.org/aspectratios.htm). As for why 1:1 worked with XMPEG, I have no idea.

[hakko504]

I think Flask/XMPEG wanted output AR which is indeed 1:1 for AVI whereas GKnot uses input AR thus requiring you to set the value to PAL 4:3.

[sarahjh69]

sorry manono

my question was about pixel shape compensation
rather than display aspect ratio. (widescreen etc)
Some settings correct for the difference in pixel
shape between tv and Pc display and i was concerned about the
4:3 (vga) or 4:3 (1:1) settings used to define if your rips
are meant to be watched on tv or computer.
In xmpeg you would select 4:3 (1:1) for rips shown on TV sets
and 4:3 (vga) for rips shown on a computer.
Gknot does not seem to be so clear on this subject.

[manono]

Hi-

You win some-you lose some-sorry. OK-try this. Go into the Options tab of GKnot. See that "Follow ITU-R BT.601 Standard" check box? Check it for TV resizing, and uncheck it for monitor resizing. Doom9 has something to say on the subject:

There's another issue here: If you go to the options tab again you will find the "Follow ITU-R BT.601 Standard" button. As I'm one of the people who thinks PC resizing is okay (and in fact every of my guides is written to respect that resizing rather than this ITU standard) I deactivate this option.

That's from his GKnot Basics Guide (http://www.doom9.org/gknot-basics-divx3.htm#res). But I ignore him and check the box anyway because I watch on a television. Is that more in line with what you wanted?