ITU or Non-ITU?

[Forteen88]

Can someone skilled at video please help me to determine the correct mode. I think the wheels looks rounder with the ITU (than non-ITU) on these uncropped screenshots (of the movie Fatal contact (2006)):

ITU:
http://megaimg.com/images/32525204780044057789.png
non-ITU:
http://megaimg.com/images/00216886736468413496.png

or am I wrong?

Thanks.

[dansrfe]

Itu......

[Usedocne]

@Forteen88

Why not just; GIMP/PS >> Ellipse Select Tool >> Draw perfect circle in middle of tire >> Then see which looks closest.

Itu......

Lol.

[Forteen88]

@Forteen88
Why not just; GIMP/PS >> Ellipse Select Tool >> Draw perfect circle in middle of tire >> Then see which looks closest.I did that (but with a circle-selector), but I thought the picture might be a bit skewed. I have not much experience in detecting ITU/non-ITU, I just heard that most movies from 2006 and after are non-ITU (my source "Fatal contact (2006)").

[Ghitulescu]

This would work only on a PC or any displays having a PAR of 1:1. In this case, ITU.

[Forteen88]

OK, thanks 'dansrfe' and 'Ghitulescu', I set it as ITU then.

@Ghitulescu: How do I know if my PC or any displays having a PAR of 1:1? Does it say in the specifications?
EDIT: @Ghitulescu Thanks again, I only use PC-displays, so it's good.

[Ghitulescu]

All the PC displays have a PAR of 1:1 (except a few old displays no one remembers, like EGA), in other words, the pixels are quadratic, or in other words, one will always find the same number of pixels within one inch (cm ;)), vertically and horizontally (usually 72-120). Unlike the inkjet printers that print eg 2400 pixels horizontally but only 600 or 1200 vertically, all values per inch.

[Usedocne]

@Forteen88

Why not just; GIMP/PS >> Ellipse Select Tool >> Draw perfect circle in middle of tire >> Then see which looks closest.

Itu......

Lol.

The reason I loled was because I misintepreted dansrfe's message - I thought it read like 'I Tee You......'

[TheSkiller]

ITU looks correct to me also. It's a shame one has to detect the correct scaling these days, DVDs are ought to be ITU only. We're having the same problem with newer PAL DVDs! :mad:

[SeeMoreDigital]

For some reason both of your PNG images have a resolution of 873x485 (higher than the NTSC DVD standard)...

(my source "Fatal contact (2006)").
Where is the 720x480 still image from the DVD source?

[TheSkiller]

He scaled the picture to square pixels with both scaling methods. Both pictures are 873x480, but the non-ITU one has been resized to 853x480 and was then padded with black vertical bars to 873 for better comparison. Nothing wrong with that imo.

[SeeMoreDigital]

Both pictures are 873x480...Actuallt they're not. Both still images are 485 pixels high...

[Forteen88]

@SeeMoreDigital: NTSC-source of that movie is 720x480.
I used this Avisynth-script to display picture correctly:

# ITU & SAR detection

avsfile = "Fatal.contact.2006.videoSD.NoSPresso.noLSF.avs" # Encoding script
format = 1 # 1=NTSC, 0=PAL
wide = 1 # 1=Widescreen 16:9, 0=Full screen 4:3 # Enter what is reported by DGMPGDec!
#########################
ITU = (format==1?10:12)/11.0*(wide==1?4.0/3:1)
SARs = """"12:11","16:11","10:11","40:33","16:15","64:45","8:9","32:27""""
ITUprof = "SDB "+(wide==1?"ANAMORPHIC ":"")+(format==1?"NTSC":"PAL")
i=import(avsfile).converttorgb
i
ab = round(height*(sqrt(45.0/44)-1))
a = spline36resize(round(width*ITU),height)
a = a.addborders(0,floor(ab/2.0),0,ceil(ab/2.0))
bb = width(a)-round(width*ITU/sqrt(45.0/44))
b = spline36resize(round(width*ITU/sqrt(45.0/44)),height+ab)
b = b.addborders(floor(bb/2.0),0,ceil(bb/2.0),0)
interleave(a,b)
scriptclip("""subtitle("Playback Resolution: "+\
string(round(width(i)*ITU*pow(44.0/45,current_frame%2)))+"x"+string(height(i))+\
"\nMeGUI Profile: "+ITUprof+(current_frame%2==1?" NON-ITU":"")+\
"\nx264 --sar "+eval("select(2*format+wide+current_frame%2*4,"+SARs+")"),lsp=0)""")

[SeeMoreDigital]

Regardless of your AVIsynth re-sizing methods. It's still necessary to know what your 720x480 DVD source looks like?

[Forteen88]

@SeeMoreDigital: Cropped 720x480 DVD source:
http://megaimg.com/images/25245783571615647958.png
http://megaimg.com/images/89163826350900417586.png

[SeeMoreDigital]

With respect. Cropped is not much use...

[Forteen88]

Sry, here's the uncropped (and not SAR-fixed):
http://megaimg.com/images/31708893590558595561.png

[Sharc]

Your source is NTSC with PAR according ITU.

[Forteen88]

Your source is NTSC with PAR according ITU.I used --sar 40:33 in x264 for this source.

[Alex_ander]

It's a shame one has to detect the correct scaling these days, DVDs are ought to be ITU only.

ITU BT.601 or ITU H.262 - that is the question.

The latter is ITU's mpeg2 standard. And it says directly, that by default (no optional extension in mpeg) the whole decoded frame (like 720x480) should be mapped to the whole active display area (like 4:3 or 16:9). There's no demand that anything captured by the first standard must be encoded 'as is' to mpeg2 for DVD.