"Follow ITU-R BT.601 Standard" - ITU or not?

[obiwan71]

Is it, as the author of GordianKnot says, "recommended to leave this checked"?
I know that this has been discussed already. But I'm still wondering about the numbers...
When the option "Follow..." is unchecked...right, I see the values and how it all works (Pixel Aspect Ratio, Display AR, PAL format and so on...).
There's a little difference in numbers when the option is checked. Where do those new values come from? It must be a matter of "standard", isn't it? :D

[Psymaster]

Hi guys and congratulations for the best divx-related site.

I've been using gordian knot for quite some time to make divx and the results are very good.

But I don't know what to do what to do with the ITU standard. In Gordian knot it says follow it, in the guide don't. So, what's the difference between using and not using the standard?

[TheWEF]

A Quick Guide to Digital Video Resolution and Aspect Ratio Conversions (http://www.uwasa.fi/~f76998/video/conversion/)

[Psymaster]

Thx WEF, I'll check it out.:)

[Psymaster]

And, what are we supposed to uunderstand from this?

[snowbeach]

"It's recommended to leave this checked.
It is the correct resizing method for DVD.
If you uncheck 'ITU-Standard' the resizing method will be similar to
the regular one used in software DVD-players like WinDVD and PowerDVD
and described in most guides." TheWEF (taken out of GKnot itself ;) )

Leave the ITU standard in GKnot checked, if you expect to watch your ripped movies on tv.

"But actually this will result in an aspect ratio that is ~2.5% off!
This fact was pointed out to me by jackei, the author of dvd2avi." TheWEF (taken out of GKnot)

??? When do we have this aspect ratio that is ~2.5% off? Checked or unchecked ITU mode? Anyway, when I Smart Crop All, I never experienced an aspect ratio that is ~2.5% off! very :confused: Please enlight me! ;)


"There's another issue here: If you go to the options tab again you will find the "Follow ITU-R BT.601 Standard" button. As I'm one of the people who thinks PC resizing is okay (and in fact every of my guides is written to respect that resizing rather than this ITU standard) I deactivate this option." Doom9 (taken from http://www.doom9.org/gknot-basics-divx5.htm )

Uncheck the ITU standard, if you expect to watch your ripped movie only on pc.

Please correct me, if I am wrong!

@some experts ;)
What to do, when I watch the movies on tv and on pc? Check or uncheck? :confused: Thanks in advance!

[TheWEF]

assuming that the dvd has been mastered according to the standard (i guess most dvds are. but it's hard to tell - some are not) you have to leave itu checked in any case.

it doesn't matter whether you want to watch it on tv or pc. tv overscan is just one of the explanations of where the standard pixel aspect ratios originate from (and not a good one).


these are the reasons why doom9 does not recommend itu (correct me if i'm wrong!):


1) major pc software dvd-players (like powerdvd or windvd) do not follow the standard. if you watch a dvd on a computer you see an ar that's 2.5% off. ever noticed? (that's why doom9 calls this "pc-resizing")

2) an aspect error of 2.5% is almost unobservable. a monitor, not perfectly adjusted, will probably introduce a bigger error. many tv-sets will show higher errors and there is no way to adjust them...

3) he does not want to rewrite his guides, itu standard is very hard to understand... :p

And, what are we supposed to uunderstand from this?

for a person who does not want to fully read and understand the document linked above (and all it's references) it doesn't matter whether itu is checked or not. - just forget about it. ;)

wef.

[kxy]

wef,

Thank you for the link, I appreciate it. I even bookmark it, for the future references.

[snowbeach]

Thank you WEF for GKnot, this great prog, and I will be tensed for your successor of GKnot! ;) Standards are always good, I will leave ITU checked! :D