gknot resizing & settings

[HotSpur]

In Doom9's recent codec guide he gives his settings for the Matrix, the resize values is 640x272, however when I recently tried to encode the Matrix using Gknot the closest I can get to that is 640x~256? Can someone please tell me what I am doing wrong? I know I can manually edit the avs file to match Doom9's settings but I'm puzzled as to why I can't recreate the values in the Gknot program.

[UHT]

try enabling/disabling the ITU-R BT.601 standard in the options

[HotSpur]

Thanks for your advice, it worked! :)

[snowbeach]

The german famous word from my area where I am from, for non-understanding: Hähhhh?

Sorry, but I still have the same problem!!!

Output resolution is not exactly calculated: DVD cover says for a movie like BLOW (16:9) 1:2,35 aspect ratio, which means that we have e.g. 640x272. The result of GKnot is 640x256 (2,5:1). Same thing for 1,78:1 (640x352). The result of GKnot is 640x336 (1,9:1 and 1,93:1).

FYI. I never use Auto Crop, because it is not working very well - it leaves sometimes black borders - so I crop manually. Then I use Smart Crop All or Smart Crop Left/Right! I often use Smart Crop Left/Right to get the desired resolution - in this case 2,35:1 and the related 640x272 of the movie Matrix! I believe that I have to use the "correct" resolution! And I always leave the ITU standard checked, but I have the same "problem" when I uncheck it!

What is going on? Is the DVD label faking me? Or what is GKnot doing to give me sometimes these weird results?

[manono]

Hi-

There are only 2 DARs (Display Aspect Ratio) in common use. They are 16:9 and 4:3. 16:9 is for anamorphic widescreen movies. The movie's AR might be 2.35:1 or 1.85:1 or 1.66:1 or many others (but not 1.78:1 as far as I know). 4:3 is used for widescreen letterboxed movies at many different ARs as well as full screen movies. For more information on this, please see Doom9's Guide Aspect Ratios Explained (http://www.doom9.org/aspectratios.htm).

After cropping the black bars, I'll then start cutting the sides until I have low Aspect Error. I've never gotten 640x256 doing it that way, but 640x272, and in a few rare instances, 640x288. As for the 1.85:1 movies-same thing-I'll cut into the sides after cutting the black bars. I always have the ITU box checked. Perhaps if you're sometimes getting 2.5:1 and 1.9:1, you're cutting into the top and bottom of the movie. Smart Crop All cuts from the top and bottom.

[snowbeach]

Hi manono!

In case of Matrix (DAR 2,35:1) - when I open the d2v porject created by DVD2AVI, Gknot gives me an output resolution of 640x352 (I always leave ITU checked too)! Cropping the black bars from the top (78) and from the bottom (79) I get 640x256 with an aspect error of 0.1%! To get the "correct" 640x272 output resolution I have to crop 21 from the left and 22 from the right - these values are the nearest to get the wished resolution (btw. aspect error is then 0%)! To be honest, I am not satisfied with this solution, because I am cropping more than 40 pix of the movie away, only to get the right resolution! :(
Maybe I should leave it as it is - without cutting the sides away - and change the resolution in the avs script to height 272?
What do you suggest?

Maybe a wish regarding the successor GKnot - it would be fine, if you could change the resolution by yourself at the resolution tab. Then you can see a possible aspect error and all the other stuff with your desired output resolution! ;)

[snowbeach]

I have experienced that manono is answering only once. That means he gives never a second answer! Why? Is my question stupid? If it is, he can give me an answer with the words, "Hey guy, your question is stupid!" and that's all. I am asking a question nicely and I think I can expect an answer here! :p Never experienced something like this at this really great forum! :(
Could anybody else say to me, if it is ok to change the avs script then, or what woul she/he suggest? Thanks in advance! :)

[manono]

Hi snowbeach-

Sometimes when I don't know the answer, it's better for me not to answer (I might get in trouble if I do-it's happened before). I already told you how I do it, and that I have never gotten 640x256. But neither have I ever ripped The Matrix. By the way, I'd recommend always cropping by even numbers.

Perhaps it has something to do with you having PAL DVDs, although, as I said, I don't know. One thing I would not recommend though, is to change the .avs script from a correct AR resolution to an incorrect one.

Did you really want me to say, "Hey guy, your question is stupid!" ? It is not a stupid question-I just don't know the answer. Nor do I doubt your experiences.

[snowbeach]

Yes, it is a PAL DVD, maybe it has something to do with it, but do not know either. ;) Maybe TheWEF can help with this???

BTW. It is always better - at least for me - to give an answer to a question. Otherwise I feel ignored! (I know, maybe this is my problem! ;) But this topic is very important to me!)

[Acaila]

I can't give you an answer, but I can give you a shared experience :)

I also ripped the Matrix PAL version, and like you said if you follow everything correctly you will end up with 640x256. Two options present itself to correct this into 640x272 (because it's still not the right AR even if GKnot says it looks ok).
1) Crop approx 20 pixels from each side.
2) Leave a small strip of black on top and bottom.
I choose the second, rather a little less compressibility than deleting parts of my picture. It still ended up nicely on 1 CD though.

[TheWEF]

what makes you think that 640x272 is "correct"?

please present your personal calculations to proove that, otherwise just trust gknot.

and forget the cover-labels... - isn't cropping different every time although all these movies are labeled 2.35?

read this (http://forum.doom9.org/showthread.php?s=&threadid=29181).

wef.

[snowbeach]

@Acaila
You are right! I cropped away the sides to get the desired AR (640x272) too.

@TheWEF
and forget the cover-labels... - isn't cropping different every time although all these movies are labeled 2.35?

read this.
True, true, true...

Thank you very much moderators for the discussion! Appreciated it! :)
I think, I am going to trust GKnot and its calculations, because I do not want to crop more than 40 pix away from the movie.

[loni_blues]

@TheWEF and @snowbeach

I always leave the ITU-R BT.601 standard option checked but I still have doubts about cropping and resolutions:

Is it safe to use auto crop and then smart crop all if you get a resolution of 640*256, while you if avoid auto crop, do a pixel crop instead to crop the black borders manually, and then smart crop all to correct for the aspect error, you get a resolution of 640*272? Which option is best? Can the auto crop function be trusted, since, as snowbeach said before, it was not working well?

Please enlighten me on this matter. Any help would be appreciated.

[snowbeach]

The most improtant thing is to get your black borders away. ;) Leave ITU-R BT.601 standard option checked. After you have "deleted" your black borders select Smart Crop All or try to crop manually to get a low aspect error. That's it... The resolution shown by GKnot is fine, it does not matter if it is 256 or 272...

[loni_blues]

I think I finally understood why the resolution changed from 272 to 256 when using auto crop + smart crop all. This sequence crops 16 lines (6 from the bottom and 10 from the top) from the original picture. Personally, I´d rather crop the black borders manually and then do the smart crop thing. In this latter case, I crop less lines from the picture and the aspect ratio is kept to 2.35, instead of the 2.5 aspect ratio I get with a 640*256 resolution. So may be, the auto crop function is not too good, after all. Are my assumtions correct?

Regards,

Loni Blues