Quantcast My Cropping/Resizing Method - digitalFAQ.com Forums [Archives]
  #1  
12-30-2002, 05:05 PM
gonzopdx gonzopdx is offline
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As promised, here it is:

First, create your .d2v as usual. Open it up in TMPGEnc (or create an .avs without any cropping/resizing), open up the settings dialog, go to the Advanced tab and open up the Clip Frame dialog. Adjust the top/bottom cropping as necessary and take note of the amounts that you need to crop. In this example, my source is a 16:9 DVD (720x480) and I need to crop 56 from the top and 59 from the bottom. Just a note, I usually don't crop from the left/right to keep my copy as close to the original as possible, also because when using this method, cropping from the left/right will mess up your resulting aspect ratio. Keep these numbers handy (in this case, 56 & 59) and do not apply the Clip Frame filter.

Encode a small clip of your movie (1 frame will suffice) and choose the correct aspect ratios and your target resolution and such. Choose Full Screen (keep aspect ratio) for your Video Arrange Method. In this case I'll be encoding at 480x352, 16:9 ratio with a 16:9 source ratio. Fine.

Now, open up your encoded clip in TMPGEnc. Open up the Clip Frame dialog again and adjust the top/bottom clipping accordingly. Take a note of the resulting resolution at the bottom (268 in this example) -- don't pay attention to the horizontal resolution (626 in this example) as TMPGEnc likes to stretch out the files sometimes for some reason which I can't figure out -- in my example, my source is 480x352 but TMPGEnc automatically stretches it to 626x352 cause it's dumb (anyone have any ideas why it does this? This is actually the first time I've encountered this, while I was writing this up. It's never done it to me before and I can't figure out why).

Now that you have your cropping numbers and sizes, you can adjust your .avs accordingly.

In my example, I'd be cropping 56 from the top and 59 from the bottom, then resizing to 480x268 (480 is the width that I'll be encoding at, 268 is the height the Clip Frame dialog gave me).

Crop(left,top,-right,-bottom)

So:

Crop(0,56,0,-59)
YourFavoriteResizer(480,26

Once you load this again in TMPGEnc to do your encoding, set the Video Arrange Method to Center and you're all set! Result, perfect aspect ratio translation!
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  #2  
12-30-2002, 10:14 PM
jorel jorel is offline
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gonzopdx,
one thing i never understand:
"my source is a 16:9 DVD (720x480) and I need to crop 56 from the top and 59 from the bottom."...as you wrote.

where you found this values??? (56 and 59)

i read tons about it,but don't understand "a thing".
how or/and where can we find crop values????
thanks in advance!
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  #3  
12-30-2002, 10:23 PM
kwag kwag is offline
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Quote:
Originally Posted by jorel
where you found this values??? (56 and 59)
When you start to click the "Top" and "Bottom" arrows under clip frame, you see that these values start to increment from 0, up to the point where you match the black bars on top and bottom with your top and bottom part of the picture. In his case, he got 56 and 59. Maybe you will get 58 and 59 or other values.
The thing I see with this process is that the output aspect will be exactly as the input. And that is the problem . If the movie is Anamorphic, so will the output. The process doesn't take into consideration that we need non-anamorphic output for VCD(KVCD)

-kwag
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  #4  
12-31-2002, 12:27 AM
Daagar Daagar is offline
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I'm trying to use this method, but things come out just ever so slightly off.

I have a SVCD source (480x480). I open it in TMPGEnc and find that I need values of 102 and 105 to crop the black borders. No prob.

I encode a few frames, and load the result into TMPGEnc. I go back to clip frame and get 184 as my resize parameter (?). So I encode with Crop(0,102,0,-105) and Resize(352,184) with a target res of 352x480. It looks close, but everyone is still a bit tall (stretched).

I know it is because I'm choosing the wrong values for Source Aspect ratio, and probably target ratio. What ratios are appropriate for a 480x480 SVCD going to a 352x480 KVCD?

The reason I'm interested in this method is because in FitCD, the black bars that result are _excessive_, taking about 2/3 of the screen (1/3 top and 1/3 bottom). This method is closer to a 'sane' widescreen...
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  #5  
12-31-2002, 12:44 AM
Daagar Daagar is offline
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Well, think I answered my own question. Trying to use this method helped me to understand FitCD further :P

I load the .d2v in TMPGEnc. Go to the clip frame option and mask out the black bars. Mark the values used.

In FitCD, take the source size (ie., 480x480), and subtract the black bars (ie., 480x(480-102-105) = 480x273). Since it isn't symmetric, I need to put "102" in Top Border. Add in overscan blocks, and poof... all done. I realize Kwag made a post similar to this recently, but I'm just now catching on

The borders still seem excessive, but that must be the "way it is"... lessening the top and bottom border would stretch the video as I've already seen. Bah.
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  #6  
12-31-2002, 02:42 AM
gonzopdx gonzopdx is offline
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Quote:
Originally Posted by kwag
The thing I see with this process is that the output aspect will be exactly as the input. And that is the problem . If the movie is Anamorphic, so will the output. The process doesn't take into consideration that we need non-anamorphic output for VCD(KVCD)
I've done quite a few encodes this way, and I have yet to run into any problems with anamorphic/not.. every time I've used this method, I've resulted a perfect preservation of the aspect ratio, no matter what resolution/aspect ratio I choose to encode at..
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12-31-2002, 02:50 AM
kwag kwag is offline
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Quote:
Originally Posted by gonzopdx
I've done quite a few encodes this way, and I have yet to run into any problems with anamorphic/not.. every time I've used this method, I've resulted a perfect preservation of the aspect ratio, no matter what resolution/aspect ratio I choose to encode at..
I did try it, but the aspect is not correct!. The output is Anamorphic. It's taller. If you resize with FitCD and encode a sample, when you compare both, the one that comes out of FitCD will have the correct aspect. If I check "Anamorphic" on FitCD's destination, then the aspect comes out identical as in your method. Unless your TV is automatically correcting the aspect, then you're fine, but you're still encoding thousands of extra bits (Anamorphic) that are expensive for the encoder. Encoding as "non-anamorphic" 16:9 increases the quality of your video quite a bit

-kwag
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  #8  
12-31-2002, 05:29 AM
gonzopdx gonzopdx is offline
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Quote:
Originally Posted by Daagar
I have a SVCD source (480x480).

What ratios are appropriate for a 480x480 SVCD going to a 352x480 KVCD?
Yes, I've done this too.

In this case, what you would do is just encode your clip at 352x480 and choose the Full Screen option for your Video Arrange Method. Since your source is 480x480 and already corrected for Aspect Ratio at that resolution, just stretching the image to the appropriate size by doing Full Screen does the trick.

Once you've done that, everything else is the same -- crop your amounts from the top/bottom and resize accordingly.

I just did Die Another Day using this method (from 480x480 to 352x480, so I know it works
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  #9  
12-31-2002, 05:46 AM
gonzopdx gonzopdx is offline
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Another Note:

When encoding your sample clip to get the resize numbers from, make sure you encode to mpeg2. In my years of encoding vcd's, I've noticed that mpeg2 seems to keep proper aspect vs. mpeg1. If you encode your sample using mpeg1, the resize numbers will always be a little bit off.
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  #10  
12-31-2002, 08:51 AM
SansGrip SansGrip is offline
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Quote:
Originally Posted by gonzopdx
In my years of encoding vcd's, I've noticed that mpeg2 seems to keep proper aspect vs. mpeg1. If you encode your sample using mpeg1, the resize numbers will always be a little bit off.
Theoretically there should be absolutely no difference between how your standalone handles aspect ratio whether its MPEG-1 or MPEG-2. The reason you see a difference might be because generally when playing an MPEG-2 standalones will obey the "anamorphic" flag.
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  #11  
12-31-2002, 09:13 AM
nicksteel nicksteel is offline
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Quote:
Originally Posted by kwag
Quote:
Originally Posted by gonzopdx
I've done quite a few encodes this way, and I have yet to run into any problems with anamorphic/not.. every time I've used this method, I've resulted a perfect preservation of the aspect ratio, no matter what resolution/aspect ratio I choose to encode at..
I did try it, but the aspect is not correct!. The output is Anamorphic. It's taller. If you resize with FitCD and encode a sample, when you compare both, the one that comes out of FitCD will have the correct aspect. If I check "Anamorphic" on FitCD's destination, then the aspect comes out identical as in your method. Unless your TV is automatically correcting the aspect, then you're fine, but you're still encoding thousands of extra bits (Anamorphic) that are expensive for the encoder. Encoding as "non-anamorphic" 16:9 increases the quality of your video quite a bit

-kwag
Should I be somehow resizing or cropping my KVCDx3 MPEG-1 16:9 NTSC films (DVD2AVI FORCE FILM) to save space?

Does resize and destination size in FitCD affect the final MPEG-1?
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  #12  
12-31-2002, 01:08 PM
Daagar Daagar is offline
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Quote:
Originally Posted by gonzopdx
Quote:
Originally Posted by Daagar
I have a SVCD source (480x480).

What ratios are appropriate for a 480x480 SVCD going to a 352x480 KVCD?
Yes, I've done this too.

In this case, what you would do is just encode your clip at 352x480 and choose the Full Screen option for your Video Arrange Method. Since your source is 480x480 and already corrected for Aspect Ratio at that resolution, just stretching the image to the appropriate size by doing Full Screen does the trick.

Once you've done that, everything else is the same -- crop your amounts from the top/bottom and resize accordingly.

I just did Die Another Day using this method (from 480x480 to 352x480, so I know it works
Thanks! I will give this a shot tonight. I was simply overthinking the problem... gotta stop playing with this stuff so late at night :P
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