Aspect Ratio and batch encoding

[d4lions]

I have noticed a few things regarding aspect ratio:

First, I tried using Autogk to encode movies that I know are in 1:1.75 true 16x9, that will fill up the whole screen, yet when I do an encode, and even though the movie is this native resolution, I still get black bars at the top and bottom? Am I missing something? how can I get the aspect ratio to stay the same?

Second, it seems that when you batch encode various movies, say each having a diffferent aspect ratio.. Letterbox vs variations (1:1.75, 1:2.35, 1:1.85) all in the same batch.. sometimes they come up with very odd aspect ratio's/frame sizes 740x544 or 740x340 (frame sizes)

Whats the best way to keep the native ratio intact?

[CWR03]

First, 1.85:1 isn't 16:9, so there should be black bars top and bottom.

Second, AutoGK is cropping to [b]maintain[b/] the proper display aspect, which means the frame size will differ between files. Are the images distorted, i. e. round objects taller than they are wide? If not, all is the way it's supposed to be.

If you keep the "native ratio" intact, you will almost always have a distorted image.

[d4lions]

Sorry.. I did type in the wrong aspect ratio..

I guess the real question is that I cant get widescreen (full size) movies to re encode to take up the whole screen?

If I understand you right, this is not possible? why would it be distorted if this is the native res?

[CWR03]

16:9 = 1.78:1 - most widescreen movies are 1.85:1 or 2.35:1. If you try to make them fill the screen they will be distorted. "Native resolution" in a DVD movie is irrelevant - there are tags telling the player what it should display, and AutoGK reads that tag to set the proper aspect ratio of the output file. You didn't answer my earlier question, "Are the images distorted, i. e. round objects taller than they are wide?"

[d4lions]

Sorry,

No the images are not distorted..

Take Jurrassic park, which is 1.85 and fills up the whole screen.. the DVD when played through a std dvd player, fills up the whole screen (granted that it is scaled by the DVD player and Projector) but regardless it fills the screen, and objects are not distorted either..

The encoding in MPEG2 per AGK, is 720x480, post AGK encoding it is 720x400, Dont get me wrong I am not "complaining about distortion" more than anything its the black bars... just a personal pet peve, I hate when DVD's are mastered that way.. but thats 3/4 of them..

I am not sure if ths because there are "80 pixels/lines" missing? or if its a scaler issue..?

I read the other thread and It was hard for me to understand the difference between "resolution vs. frame size"

I personally wouldnt mind a larger file size if I can fill up the screen?

Thanks,

ADS

[jggimi]

Jurassic Park, according to imdb.com, was shot in Spherical 35mm at .... 1.85:1. I don't have the DVD, but a 16:9 edition must have either 1) some letterboxing or 2) some cropping or 3) resizing in order to get it down to 1.78:1 for DVD. If it was #3, you may or may not be able to notice a 4% aspect error.

[CWR03]

As jggimi said (and I said earlier), 1.85:1 is not 16:9; it isn't supposed to fill the screen. If I'm not mistaken, with AutoGK the only way to get it to "fill the screen" is to crop the left and right.

[d4lions]

Why crop the left and right..

I realize that true 16x9 is 1:1:7, however it seems in my experience that it is only movies shot in 1:1.85 that fill the whole HDTV screen (Which is 1.1.7 by definition). Most of the 1:1.7 movies seem to be in letterbox (IMHO). I definately need to stop being loose with the vocabulary.. it can get confusing, and lead to misinterpretation.. so I appologize..

Again, I am not sure if this is a "scaling" issue during playback vs an encoding issue.. I just notice that some sources that are 720x480 source come out with different " odd resolutions" They are proportionate, and look great, but there are the infamous black bars, where there werent any on the native DVD.. It could be that I just need to fork over some $ for an HD Leeza scaler... or that I need a new flavor of Crack (the blue ones with the golden sprinkles are making me see black bars that arent there..) lol..

regardless, most of them show up as a film source 720x480 (most dvd's are mastered this way) (again IMHO, that I have noticed)

native HD 1280x720 pixels per the PJ/Flatscreen

Why crop left and right?

Does anyone have an idea how to find out if it is the scaler? or the Encoding..

Is it a setting? in AGK?

[manono]

Hi-

I realize that true 16x9 is 1:1:7, however it seems in my experience that it is only movies shot in 1:1.85 that fill the whole HDTV screen (Which is 1.1.7 by definition). Most of the 1:1.7 movies seem to be in letterbox (IMHO).

It's 1.78:1. All 1.85:1 movies on 16:9 DVD have small black bars on the top and bottom because they're slightly wider than a 1.78:1 (aka 16:9) HDTV. The reason you don't see those bars when watching the DVD is that they're lost in the overscan. If you were to open that same DVD (Jurassic Park, for example) in DGIndex, you'd see the bars.

The reason CWR03 said that to get rid of the black bars and maintain AR you have to crop from the left and right is that if you just crop the top and bottom to remove the bars and then resize to 1.78:1, you're left with a significant AR Error. To fix that and have it fill the entire screen, you'd need to crop from the left and right a little bit. And there's no way in the world I'd ever recommend doing that.

I'm not quite sure why you say that you get black bars when viewing the AVI. Assumng that AutoGK did its job, there shouldn't be any black bars in the AVI itself. You can confirm by opening it in VDubMod. So, assuming no black bars in the AVI, then the bars are added by the player. I don't know exactly how you're getting the AVI to the HDTV. If it's done from computer, then there's no overscan, and the bars are added by the player. If you have a DVD/MPEG-4 player, then it must be scaling without overscan, and again, the bars are being added by the player.

I hate when DVD's are mastered that way.. but thats 3/4 of them..

Don't tell me that you're one of those guys that bought his HDTV expecting not ever to see black bars again. Around here we believe in OAR (Original Aspect Ratio). Older movies are meant to be displayed with pillar bars. Movies wider than the 1.78:1 HDTV are meant to have bars on top and bottom.

[CWR03]

I think I've got it figured out...d4lions, pay attention please.

When you open a DVD rip that's 720 x 480 and it fills the screen with no black bars, even though the original film was 1.85 to 1, it's called "anamorphic." That means there are coding tags that tell the DVD and the ripped file to play at that width, which means the top and bottom will have black bars. If you force 16:9 aspect on that source, it will appear stretched. If that works for you, great. If you don't want it stretched, and you don't want the black bars, you must crop left and right. There are no other possibilities.

One of the things you seem to be having trouble with is that 720 x 480 is NOT 16:9, it is 1.5 to 1. Therefore maintaining "native resolution" is not an option in any circumstance, as there is no original source that is 1.5 to 1.