Aspect Ratio Conundrum

ViSCeRaL · **Posted:** Wed Oct 11, 2006 7:18 pm **Post subject:** Aspect Ratio Conundrum

I'm currently ripping an NTSC DVD which has a frame size of 720X480 and I need to crop it to 1.85:1 OAR. I only need to crop it by 2 pixels on the width, making the frame size 716 wide.

I'm aiming for a 1/3rd DVD rip, so want to get the resolution as close to the original as possible.

The problem I've got is, with the width set to 704 pixels, GK is telling me that I've zoomed the width to 111%. How can this be? I'd have to be at ~795 pixels wide to be zoomed that much, surely?

unskinnyboy · **Posted:** Wed Oct 11, 2006 9:28 pm **Post subject:**

A short unprocessed VOB sample please.

ViSCeRaL · **Posted:** Wed Oct 11, 2006 11:59 pm **Post subject:**

Here you go:

http://rapidshare.de/files/36401579/vobsample.rar.html

TIA

unskinnyboy · **Posted:** Fri Oct 13, 2006 6:34 am **Post subject:**

I am not sure what is happening here myself and it is all probably because I haven't been out of touch with GK..

What I see is this..

The zoom is actually 107%, since the DVD is not anamorphic.

ViSCeRaL · **Posted:** Fri Oct 13, 2006 8:44 am **Post subject:**

unskinnyboy wrote:

The zoom is actually 107%, since the DVD is not anamorphic.

I'm not to worried about the exact zoom percentage, just that it's well over 100% at 704 width. Input resolution is 740, cropped by 2 pixels in your screenshot, yet it's still reporting that the width is 107% zoomed at an output resolution of 704.

Unless I'm missing something, the maths doesn't add up.

spudthedestroyer · **Posted:** Fri Oct 13, 2006 9:20 am **Post subject:**

Right, your going to feel like a complete plum but i burst out laughing when i saw it. H-Zoom mate, that's HEIGHT zoom (up and down).

Your cropping 68 + 68 = 136 pixels from the top and bottom, and 2 left and right.

dvd res is 720x580 - 2x136 = 718 x 344 cropped. Now your stretching the vertical to 368 from 344 which is 107% of the original. Your width is being reduced to 96%, that's W-Zoom

You need to reduce your resolution or your zooming vertically, zooming in any form is bad. The problem you have is the AR is being reported as 1.9:1, that's either a very strange film, a bad/zoomed master or bad overcropping.

Check to see if you have ITU checked btw, non-anomorphic probably means it should be checked

/me points and laughs :outsider:

ViSCeRaL · **Posted:** Fri Oct 13, 2006 9:32 am **Post subject:**

spudthedestroyer wrote:

Right, your going to feel like a complete plum but i burst out laughing when i saw it. H-Zoom mate, that's HEIGHT zoom (up and down).

You're right, I'd read it as Horizontal Zoom, overlooking the W-Zoom field because it wasn't red. :lol:

Yes, I feel a complete plum. :oops:

Quote:

You need to reduce your resolution or your zooming vertically, zooming in any form is bad. The problem you have is the AR is being reported as 1.9:1, that's either a very strange film, a bad/zoomed master or bad overcropping.

Bad mastering I think.

Quote:

Check to see if you have ITU checked btw, non-anomorphic probably means it should be checked

I'm pretty sure it is, I tried checking and unchecking to see if it made a difference.

Quote:

/me points and laughs :outsider:

/me wishes ground would open up and swallow me. :lol:

spudthedestroyer · **Posted:** Fri Oct 13, 2006 10:04 am **Post subject:**

Quote:

I'm pretty sure it is, I tried checking and unchecking to see if it made a difference.

Unchecked gives you a bit more horizontal, checked doesn't. I figured it might be squashed a bit which would explain the AR. Try unchecking and looking for circular objects

ViSCeRaL · **Posted:** Fri Oct 13, 2006 10:10 am **Post subject:**

spudthedestroyer wrote:

Unchecked gives you a bit more horizontal, checked doesn't. I figured it might be squashed a bit which would explain the AR. Try unchecking and looking for circular objects

Unchecked looked a bit stretched, I'm pretty sure I left it checked for that reason. At least I can look at it again without the goober glasses on now, so it should make a little more sense. :lol:

spudthedestroyer · **Posted:** Fri Oct 13, 2006 10:15 am **Post subject:**

Get your compass and ruler :wacky:

Well at least the AR mystery is solved

ps.

ViSCeRaL · **Posted:** Fri Oct 13, 2006 10:47 am **Post subject:**

I was wondering why you posted a picture of an apple, maybe to demonstrate the ideal item for checking good AR.

Then I looked at the filename. :lol:

Yes, I'm a plum. :oops:

spudthedestroyer · **Posted:** Fri Oct 13, 2006 7:31 pm **Post subject:**

damn, what kind of apples do you get DJ? then again, i guess it could just be your eyes... would explain the not noticing which zoom was which.

Good movie your ripping btw?

ViSCeRaL · **Posted:** Fri Oct 13, 2006 9:06 pm **Post subject:**

spudthedestroyer wrote:

Good movie your ripping btw?

Just back catalogue stuff, trying out AFR now we've lost the scene shackles. :lol:

unskinnyboy · **Posted:** Sat Oct 14, 2006 12:57 am **Post subject:**

spudthedestroyer wrote:

Right, your going to feel like a complete plum but i burst out laughing when i saw it. H-Zoom mate, that's HEIGHT zoom (up and down).

FUCK, Please do me a favor and kick me on my butt. I missed that too.. :matrix:

spudthedestroyer · **Posted:** Sat Oct 14, 2006 10:41 am **Post subject:**

yeah but i'm guessing that you don't use gknot usb? Vis has no excuse :lol:

I would have thought H-Zoom would be Horizontal zoom if i'd have read it in isolation but all the boxes around it correspond to width followed by height. too

I don't tend to recognise words but location on the gknot gui now, so i 'blindly' click the right buttons without reading the labels

unskinnyboy · **Posted:** Sat Oct 14, 2006 6:57 pm **Post subject:**

It's been a long time since I've used GK, so I guess I can use that as an excuse. :lol:

But I used to use it a lot before, so this kinda shows how bad my memory is.. :oops:

Aspect Ratio Conundrum

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