Resizing help

[chobo321321]

I am trying to resize an AVI encoded in Xvid, to mpeg2 (NTSC). The AVI's source resolution is 624x336, and has no letterboxing. I am not sure what size I need to resize the image to, and how much letterboxing to give it, if any.

I just have one more quick question.

Should I be resizing the width to 704, or 720?

Any help is appreicated. Thanks

[chobo321321]

I'm sure someone knows I did check out the guides, but this resolution is kinda weird (to me anyway), so I just need someone to verify my assumptions.

[Grimey]

are you making a dvd or svcd? and what program are you using to encode?

assuming your making a dvd with tmpgenc, just select a ntsc dvd(the higher resolution one) in the wizard, and when setting it up, select fullscreen(keep aspect ratio).

[chobo321321]

I'm using CCE SP 2.5 with avisynth.

[trevlac]

624x336

This is what I would do:

1) Pad top and bottom so 624x336 is a 4:3 ratio So pad to 624x468.
2) NTSC 4:3 is actually 711x486. You could resize to this and crop(pad) to 704x480 (or 720x480)


There are a few ways to get there, but hopefully this is the most clear.

Here is a reference:
http://www.quantel.com/domisphere/infopool.nsf/HTML/565C7D89F2D64F3680256C8000444A4D?O...light=2,aspect

[monzie]

Well if it was me, I would encode at 4:3 with a vertical of 336 (or 352) with borders of 72 T & B (or 64 T & B if 352).....no need to touch the horizontal..this if for ntsc (4:3 Tv's).

624 X 336 is NOT a 4:3 ratio its 16:9 anomorphic...so you need to add T & B borders.

If its for 16:9 widescreen TV then its 464 vertical, encoded at 16:9 with minimal 8 T & B borders (hardly visible).

HTH

[trevlac]

I love this place!

Well if it was me, I would encode at 4:3 with a vertical of 336 (or 352) with borders of 72 T & B (or 64 T & B if 352).....no need to touch the horizontal..this if for ntsc (4:3 Tv's).

I do not follow. How do you start with 624 and get 704 or 720 and not touch the horizontal?

624 X 336 is NOT a 4:3 ratio its 16:9 anomorphic...so you need to add T & B borders.

Anamorphic is created by a lense. The image is squished so it fits in a smaller frame. Unless he sees it squished on the PC (which I doubt), it is not anamorphic.

Here is a reference: http://www.quantel.com/domisphere/infopool.nsf/HTML/dfbAnamorphic?OpenDocument


I did assume the desired output would be 'letter boxed' on a 4:3 TV.

[chobo321321]

I thought the aspect ratio has to be 2.35 to be anamorphic. The ratio on this AVI is 1.85. I try doing a fw encodes with the settings you guys gave me. Thanks for the help, this stuff can get pretty confusing.

[monzie]

Where do you get 720 or 704 playback from on a 4:3 NTSC encoding?...its 640..but I could be wrong

I thought all resolutions above 1.77:1 where classed as anomorphic from a generic DVD/mpeg2 standpoint due to the inevitable letterboxing regardless of the DAR?.......but I could be wrong

Whats a pc and pc pixels got to do with DVD encoding?...its designed for DVD players and TV playback...thats why we ALL WORK FROM TV SCAN LINES.....aka the VERTICAL res...but I could be wrong.

Maybe reading these will help..but I could be wrong......

https://www.videohelp.com/forum/userguides/174200.php

http://www.doom9.org/index.html?/aspectratios.htm

Whats do these mean?:

1) Pad top and bottom so 624x336 is a 4:3 ratio So pad to 624x468.
2) NTSC 4:3 is actually 711x486. You could resize to this and crop(pad) to 704x480 (or 720x480)

Is "resize, crop, and pad" a needlework term that your mum/girlfriend/wife might understand? Is it like knitting?

What do your movies playback like.......a yarn of shrunken wool?

[/b]

[trevlac]

I'll try to be nice ... but you seem to be a bit of an ass hole.

Where do you get 720 or 704 playback from on a 4:3 NTSC encoding?...its 640..but I could be wrong

You are wrong. DVD is 720 or 704 or 352 x 480 for NTSC. Since you like message board references ... here is one ...

https://www.videohelp.com/dvd

I thought all resolutions above 1.77:1 where classed as anomorphic from a generic DVD/mpeg2 standpoint due to the inevitable letterboxing regardless of the DAR?.......but I could be wrong

I already gave you a quantel link on what anamorphic is. I guess you could make an anamorphic dvd from the avi source. But if you are going to watch on a 4:3 tv, what's the point?

Whats a pc and pc pixels got to do with DVD encoding?...its designed for DVD players and TV playback...thats why we ALL WORK FROM TV SCAN LINES.....aka the VERTICAL res...but I could be wrong.

You are really clueless. The poster started with an xvid avi. So this was created to play on a .... PC? Of course. So he needs to adjust. And what the f* does "we ALL WORK FROM TV SCAN LINES" mean?

Maybe reading these will help..but I could be wrong......

https://www.videohelp.com/forum/userguides/174200.php

http://www.doom9.org/index.html?/aspectratios.htm

Those are nice try's but those people don't really completely know what they are talking about. Yep. Doom9 kinda wanders on that one.

Since you like doom9, try this: http://www.doom9.org/index.html?/capture/start.html

Start with section 3 to learn a little about analog video ... then go to sections 4 and 5 for an idea about 4:3 frame sizes and resizing various source.

Finally go back and read DJRumpy's stuff.

PS: Also read the sources from the doom9 guide. Did the Rumpy guide or Doom9's ar stuff have any sources? Maybe you should check a few things.

Whats do these mean?:

1) Pad top and bottom so 624x336 is a 4:3 ratio So pad to 624x468.
2) NTSC 4:3 is actually 711x486. You could resize to this and crop(pad) to 704x480 (or 720x480)

Maybe you understand avisynth script. That is what the original poster uses.

AddBorders(0, 66, 0, 66)  #Pad to get 624x468 aka 4:3 AR
LanczosResize(712,486)  # use 712 because your color space is YUV
Crop(4,3,-4,-3)  #crop to 704x480

Is "resize, crop, and pad" a needlework term that your mum/girlfriend/wife might understand? Is it like knitting?

What do your movies playback like.......a yarn of shrunken wool?

We were ok up to here. Now it's clear you are just an ass. Not sure why I waste my time

[chobo321321]

I ended up going with a 720x460 resize with 10 pixel letterboxing on the top and bottom. Hopefully it doesn't look squished or stretched. I wish people would come out with some more DVD guides, everything seems to be geared towards SVCD's "

update:
Thanks for all the help trevlac! I'll do another encode using those settings. That other guy did seem kinda confused.

Quick Question:

If I was to encode to widescreen format would I use 720x460? I'm assuming your resize, and cropping method would get the encode to look fullscreen on a 4:3 TV.

Thanks for all the help guys This can be a very confusing subject, even for the novices.

[trevlac]

I ended up going with a 720x460 resize with 10 pixel letterboxing on the top and bottom. Hopefully it doesn't look squished or stretched. I wish people would come out with some more DVD guides, everything seems to be geared towards SVCD's "

update:
Thanks for all the help trevlac! I'll do another encode using those settings. That other guy did seem kinda clueless.

My friend.

1st some assumptions. You want a letter boxed dvd to play on a 4:3 tv.

Let's look at it another way:

- You are starting with an image aspect ratio of ~ 1.85
- If you want to fit it into a 4:3 screen you need a ratio of 1.333
- If you do not want to skew the image, you simply add borders
- My 1st step was to go from a 1.85 image ar to a 1.333 image ar

- Now the problem is that PC pixels are not the same shape a tv pixels
- Your source is for PC pixels
- PC pixels are squares. NTSC pixels are skinny rectangles.
- One way to deal with this is to just resize from what you have to a NTSC tv 4:3 frame
- 711x486 is really 4:3 because NTSC pixels are .9116 x 1 wide
- 711 * .9116 / 486 = 1.333 Check out the quantel link.

PS: Quantel makes $100K+ broadcast digital video processing equipment. They do not run rinky dink websites. (sorry about that )

- So .... Resize your pc 4:3 pixels to NTSC 4:3 pixels ... step#2 in the script

- Now our problem is that 712x486 is not a DVD size. Yep, strangely enough digital sizes are different from broadcast.
- But that is easy to fix. Just crop like in step #3

[trevlac]

Quick Question:

If I was to encode to widescreen format would I use 720x460? I'm assuming your resize, and cropping method would get the encode to look fullscreen on a 4:3 TV.

My example would make it a letter boxed movie on a 4:3 TV. PS: An anamorphic dvd should play as a letter boxed movie on a 4:3 TV. The difference would be you doing the letter boxing or the DVD player doing it.

If you want to make a 1.78 anamorphic, pad in step #1 to 350. When you resize in step #2, the image will be streatched tall and skinny. The resize will do 2 things. It will adjust for TV pixels and it will make the image anamorphic (with a little border so it comes back out as 1.85). If you do this, you need to make sure you set the correct flags when you author. On a 4:3 tv, you should see the same result as the other way. On a widescreen, it should fill the screen except for a small border due to the fact the source is 1.85.

Try both

[chobo321321]

Now it all makes sense Thanks for taking the time to clear that up, I appreciate it.