Letterboxed Aspect Ratio

Second Element · Post by **Second Element** » Wed Nov 02, 2005 2:07 am

Before anyone says it, yes, I've read thru the guides ( ^_^x ) and I have mixed 4:3 and 16:9 footage many times before. But I'm completely at a wall with this one.

Okay, so working on an AMV of various sources- some Widescreen and others regular TV field. The majority of my sources are Full Screen, so I have decided to make that the aspect ratio for the entire AMV. All my widescreen footage I have panned and scanned from left to right and all over the place as I need to fit in with the 4:3 ratio. However, one of my movie sources is Letterbox, and no matter how many different ways I have tried calculating it and re-writing the AVS scripts, there just seems to be no way to scale it to 4:3 ratio. If my entire video were going to be a 16:9 ratio, I would simply just crop off the letterbox borders and work with it that way- but as I said, most of my footage is 4:3, so that is what the video is going to be set as.

So my question is- is there any possible way whatsoever to get letterboxed footage resized and cropped and etc. for a 4:3 ratio? If there isn't, I'm just going to have to toss this particular movie out of the AMV, because I don't like switching between 16:9 and 4:3 ratios in the same AMV ( just my preference ). Thankfully, none of my other movie sources are letterboxed- just widescreen, which is easy to pan and scan and crop to fit the 4:3 ratio. But I think I'm just plain screwed when it comes to the letterboxed footage.

Keeper of Hellfire · Post by **Keeper of Hellfire** » Wed Nov 02, 2005 2:50 am

You have to resize it to a width as if is 16:9, and calculating from this width a height which is correct for 4:3. This means, resize it to 854 x 640.

Crop 80 from top and bottom (the black bars). Then crop from the sides so that the remaining width is 640.

the Black Monarch · Post by **the Black Monarch** » Wed Nov 02, 2005 2:55 am

The correct amount to crop from the top and bottom is almost never 80. Import the raw 720x480 video stream into Virtualdub and save a frame to the clipboard. Then open up Paint, paste from the clipboard, zoom in, and measure how many pixels you need to cut off.

^
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(Is obsessive)

Scintilla · Post by **Scintilla** » Wed Nov 02, 2005 3:15 am

Wouldn't it make more sense to crop 64 from the top and bottom, resize to 960x480 (or 848x480 if you resized the 4:3 footage to 640x480), and then chop off the sides to make it 720x480 (or 640x480)?

Of course, if you're using a program like Premiere Pro, you don't even have to chop off the sides...

Keeper of Hellfire · Post by **Keeper of Hellfire** » Wed Nov 02, 2005 3:32 am

the Black Monarch wrote:The correct amount to crop from the top and bottom is almost never 80.

Why not? If you have resized to a height of 640 and have to crop it to a height of 480, the difference is 160. Since I don't assume the borders have different heights, you have to crop 80 from top and bottom. Btw, if you know to use VirtualDub(Mod), you don't need Paint to figure out how much to crop.

But since they made it letterboxed and not anamorphic, the original aspect ratio may not be 16:9. Probably it's cinema widescreen, which is 1.85:1. In this case you have to resize to 888 x 666 and to crop 93 from top and bottom. If it's cinemascope (2.35:1, I don't think it's used for anime), you better don't use that clip.

Scintilla · Post by **Scintilla** » Wed Nov 02, 2005 3:41 am

Keeper of Hellfire wrote:
the Black Monarch wrote:The correct amount to crop from the top and bottom is almost never 80.
Why not? If you have resized to a height of 640 and have to crop it to a height of 480, the difference is 160. Since I don't assume the borders have different heights, you have to crop 80 from top and bottom. Btw, if you know to use VirtualDub(Mod), you don't need Paint to figure out how much to crop.

But since they made it letterboxed and not anamorphic, the original aspect ratio may not be 16:9. Probably it's cinema widescreen, which is 1.85:1. In this case you have to resize to 888 x 666 and to crop 93 from top and bottom. If it's cinemascope (2.35:1, I don't think it's used for anime), you better don't use that clip.

Again, wouldn't this be a lot easier if the black bars were simply cropped <i>before</i> resizing? You can tell how much to crop just by looking at it in VirtualDub (I could have sworn 64 worked for most letterboxed anime), instead of letting the height you resized to define how much you need to crop. And then it's a simple matter to resize to ???x480.

Keeper of Hellfire · Post by **Keeper of Hellfire** » Wed Nov 02, 2005 3:47 am

There is no difference in the result if you crop first and resize than or do it vice versa. With resizing it first I find it easier to calculate.

But yeah, in one thing Scintilla is right: I assumed that you resize to 1:1 PAR. If you want to keep the NTSC PAR, the sizes are 960 x 640 or 999 x 666, if you follow my way.

the Black Monarch · Post by **the Black Monarch** » Wed Nov 02, 2005 3:50 am

Keeper of Hellfire wrote:I don't assume the borders have different heights

[yoda]That is why you fail.[/yoda]

Keeper of Hellfire · Post by **Keeper of Hellfire** » Wed Nov 02, 2005 4:01 am

Keeper of Hellfire wrote:... resize than or ...

Damn typo, damn missing edit button. Of course I meant then.

Second Element · Post by **Second Element** » Wed Nov 02, 2005 7:08 am

Thank you very much to everyone for all the replies- I'll do what you suggested. You won't hear back from me on this unless I manage to 'tard it up somehow ^_~x