digitalFAQ.com Forums [Archives]

digitalFAQ.com Forums [Archives] (http://www.digitalfaq.com/archives/)
-   Video Encoding and Conversion (http://www.digitalfaq.com/archives/encode/)
-   -   KVCD: Aspect Ratios, Cropping, and Resizing observations (http://www.digitalfaq.com/archives/encode/2680-kvcd-aspect-ratios.html)

phibertron 02-18-2003 08:42 PM

Aspect Ratios, Cropping, and Resizing observations
 
I'd like to start off by saying that I am n00b, these are just my observations.

I know we already have some great filters like AutoCrop, Grip, etc, that deal with cropping and resizing.
It’s just that for me to truly understand the relationship between all of the numbers,
I mostly just do it all manually to make sure that I get it right and understand it.

I have read a few threads here about people wanting to encode for a 16x9 display.
My television is a widescreen, so I too am posed with the question of what to do.
Do I encode for 4x3 or do I encode for 16x9, knowing that VCD and SVCD do not support the 16x9 flag.
I had been encoding for 4x3 and then using my TV’s zoom feature to compensate,
Well that in itself is a compromise of quality, because you are now relying on your TV’s scalar,
Of which may or may not do a good job at it.
The other problem is if what you encode is going to be given to someone, 4x3 is probably the safest.
But for my own encodes, I want it to be geometrically correct for my TV.

This is what I have been doing thus far if my Source is 16x9 Anamorphic 2.35:1


If the Intended Display is 16x9
===============================

Crop the source accordingly, and resize only the width

Crop(0, 60, 0, -60)
BilinearResize(528, 360)

Source Aspect ratio in TMPGenc set as 1:1 (VGA)
Video Arrange method in TMPGenc set as Center
Output Aspect ratio in TMPGenc set as 4x3

This viewed on my widescreen looks better than below, and I don't have to change the tv's aspect ratio to compensate.


If Intended Display is 4x3
==========================

Crop the source accordingly, resize width, and height for a corrected 4x3 Aspect Ratio

Crop(0, 60, 0, -60)
BilinearResize(528, 272)

Source Aspect ratio in TMPGenc set as 1:1 (VGA)
Video Arrange method in TMPGenc set as Center
Output Aspect ratio in TMPGenc set as 4x3

This viewed on my widescreen looks good, but I have to change my TV’s aspect ratio


My DVD player is a Panasonic RV32, and it says that it can play SVCD, but it can't, have to do the VCD header trick.
I can pretty much throw anything at it as far as resolution or bitrate, even a 16x9 flag and it doesn't complain,
as long as I do the VCD header trick.
Oh yeah and if you are wondering, my TV is a Pioneer Elite PRO710HD 64"

The next thing I am trying to tackle is the overscan thing
I have gone as far a up to 8 on both sides (16 total) and I do not see any bars,
think it has to do with the way my set overscans, need to find out where the limit is at.
It also appears that the more I adjust for overscan, I may have to adjust for height,
as the aspect ratio is not staying correct, only a little though.
My fear is using too much overscan when giving an kvcd to someone.

Phibertron

phibertron 02-18-2003 09:04 PM

I guess the biggest thing that I notice, which may or may not be correct,
is if the height of the resized video is correct for its aspect ratio,
wether for 4x3 or 16x9, then no matter what width you choose,
the displayed video will have the correct ratio.

I hope I described that right..

Phibertron


All times are GMT -5. The time now is 09:43 AM  —  vBulletin © Jelsoft Enterprises Ltd

Site design, images and content © 2002-2024 The Digital FAQ, www.digitalFAQ.com
Forum Software by vBulletin · Copyright © 2024 Jelsoft Enterprises Ltd.