need help converting DVD to XviD with correct aspect ratio

[ajcool]

Hi guys,

Okay I am having a really hard time with this one. I am using AutoGK to convert my DVD's to XviD. My question is, how can I figure out the exact proper aspect ratio of the source DVD so I can turn off the auto mode and have perfect rips.

I feel like AutoGK is incorrectly calculating the aspect ratio on some movies. What do you guys do that is an easy way to get the proper aspect ratio of the actual DVD before you convert it.

Thank you

[Ranguvar]

www.imdb.com :)

Crop out the black borders, then resize to a resolution of that aspect ratio.

[ajcool]

So I am just supposed to look up everything on IMDB and base the AR on that? Is there not a more exact way to do it using some kind of program?

[smok3]

I feel like AutoGK is incorrectly calculating the aspect ratio on some movies
how did you figure?

[Ranguvar]

Well, you could crop and then stretch until it feels natural...

But IMDb is as accurate as it gets. There's only a few aspect ratios that are chosen between when filming, so you just need to resize back to that AR.

For example, the first Saw movie: http://www.imdb.com/title/tt0387564/

It says 1.85:1, so I'd crop and then resize to something that's both mod16 and around 1.85:1. And of course, higher resolution if you can afford more bitrate, but generally you don't want to exceed 720 width, since many standalones will refuse higher than that, and it doesn't look too much better at all IMO. So 704x386 might be good for a transparent encode (lots of bits). Less for less bits. And keep in mind, something 2.35:1 may demand less bits even if there's a very high number of pixels for the width, since height is so low. I generally choose my width, divide by the AR, divide by 16, round, and then multiply by 16.

There's AR calculators that will help you come up with the resolution, Google for them.

[ajcool]

Okay so for example I am doing Hustle and Flow. It says the AR is 1.81:1. How do I calculate the resolution for that? Meaning what width what would that equal?

So every movie I encode with AutoGK on Auto width mode will automatically calculate the AR correctly?

[Brother John]

So every movie I encode with AutoGK on Auto width mode will automatically calculate the AR correctly?
If the DVD is flagged correctly (and it would be a case for returning it to the store as defective if it wasn’t) then yes.

[smok3]

i must say i'am still interested how do you know that AutoGK is incorrect? (and i'am not saying it is correct, just wonder?)

[ajcool]

i just feel like if i could input correct ratio myself i would be better off...

[snowden]

i do a screencap of a vob file, then of an avs i just made to see if it is as close to the vob one. if it looks as close to 'cropped+zoomed' as possible, then it's jackpot. otherwise i put up with what i can get.
i use gordianknot, and i turn off ITU compliance most of the time; but i have come across some strange dvds that resize incorrectly if i leave it on. that's why i just use screenshots!

[alfixdvd]

Try with Aspect Calculator: http://aspect.fre3.com

You can open a d2v file, crop, and resize to maintain aspect ratio, calculate bitrate, size with overhead, an Qf (bits/pixel).

You can save a avs file with the cropped/resized values selected.

[DVFs_DrinkOrDie]

I feel like AutoGK is incorrectly calculating the aspect ratio on some movies.

Your DVD is probably anamorphic wide screen. That's usually the case when this problem occurs. Just something to think about.

[Ranguvar]

i just feel like if i could input correct ratio myself i would be better off...
Again, you can't get better than what IMDb says... it should also say on most DVD boxes.

[Brother John]

IMdB ist as unreliable as DVD boxes because they only list the default AR numbers. If it says “1.85:1” nothing guarantees you that the actual videostream on the DVD is exactly 1.85. Most likely it won’t be. DVDs mastered according to ITU-R BT.601 don’t have those “round” numbers anyway. And others probably will deviate as well because of imperfections in the DVD production process or because of your cropping.

That said, there’s no reason not to go with the PAR derived from DGIndex (which is what AGK does). That’s the most accurate value you’ll get.