What's the correct resolution for a film with aspect 1.85 on a dvd?

[newuserxyz]

Hello!

I wanted to convert some DVD's to h264. I used staxrip. All of films originally are made in 1.85 (according to imdb).
Therefore I expected the videos on dvd in 720x576 with 12 lines letterbox top and bottom (videos in 720x552).
Actually the first one is in 720x576 without letterboxing, the second one is in 710x556 and only the third one is in the expected format of 720x552.
Is it sloppiness or is there any math I don't know??


cheers!

[Ghitulescu]

Yeap, it's called anamorphic

WS movies can be presented as LB or anamoprhic.

LB: you have 4:3 with mating (black bars top and bottom).

Anamorphic: the image is 16:9, however it looks stretched because it's the duty of the player to stretch it back during playing.

However, there is a second issue: people remove the mating and reconsider the PAR (I hope they do) ;) and yield various resolutions like 640x432 ...

How do you managed to find these 12 lines (bzw. 522 scanlines)?

[newuserxyz]

Äh, I don't understand your answer :confused:

The PAL MPEG2 DVD format is allways 720x576 and every other resolution is pressed in that format. The PAR for MPEG2 DVD 16:9 is fixed too and is 1,422 (or 1,4587 ITU).
Therefore every film originally made with aspect ratio 1.85 must have the format 720x552 (with 12 lines of letterbox on the bottom and top to fit 720x576).

Am I right? :devil:

[Limit]

I'm not an expert, but afaik DVDs support only two PARs, one for 16/9 (PAR 16/11) films and one for 4/3 (PAR 16/15) films. So you must only decide which of them has been used for the respective DVD (alternatively you can use MediaInfo) and set the PAR @ x264 accordingly. Cropping in any way would not change the PARs, so you can just crop as needed.

[Ghitulescu]

Äh, I don't understand your answer :confused:

The PAL MPEG2 DVD format is allways 720x576 and every other resolution is pressed in that format. The PAR for MPEG2 DVD 16:9 is fixed too and is 1,422 (or 1,4587 ITU).
Therefore every film originally made with aspect ratio 1.85 must have the format 720x552 (with 12 lines of letterbox on the bottom and top to fit 720x576).

Am I right? :devil:


This is half truth. The good part is the first sentence, the wrong is the lower half.

It depends where you look at: TV or PC.
Because PC monitors have square pixels (PAR=1) while NTSC/PAL TVs have rectangular ones.

To have circles on PC the frame should have 768x576 pixels. For NTSC it would be 640x480 (guess how EGA/VGA was invented). To have circles on a PAL TV you need only 720x576 pixels. I still don't understand how 720 / 522 = 16:9 (720x405 ???, 768x432 PAR=1 or 720x432 PAL). To your luck, PAR for HDTV is always 1:1 (PC or TV).

The frame size serves only as a "storage", the image is formed by taking one frame from the "image tank" that has 720x576 or x480pixels, and stretching it using DAR and PAR to fit the viewing device (TV).

Hopefully you understand now that subtle difference;)

One more thing (Columbo ;)): some TV shows on DVD, especially the British, have a black border, designed to overcome the overscan (not to loose details underneath the TV's wooden frame). Which leads some Divx enthusiatics to crop the movie to strange frame sizes. That would pose slight problems later on while watching on TV (aspect ratio, zooming, scaling).

[Keiyakusha]

Äh, I don't understand your answer :confused:

The PAL MPEG2 DVD format is allways 720x576 and every other resolution is pressed in that format. The PAR for MPEG2 DVD 16:9 is fixed too and is 1,422 (or 1,4587 ITU).
Therefore every film originally made with aspect ratio 1.85 must have the format 720x552 (with 12 lines of letterbox on the bottom and top to fit 720x576).

Am I right? :devil:

As far as I understand, you right, but I think you should look at the back cover of your DVD instead of IMDB, because even if film originally 1.85, it can be cropped to 16x9 for DVD release in some countries

Also post some screenshots. Will be good if you can take screenshot with some object that should be near-perfectly round.

[Gokumon]

As far as I understand, you right, but I think you should look at the back cover of your DVD instead of IMDB, because even if film originally 1.85, it can be cropped to 16x9 for DVD release in some countries

You seem confused. To go from 1.85:1 to 16x9 would be through an opening up of the matte not by cropping (unless you have someone doing some sort of weird zooming but this is usually pretty rare). All 1.85 movies are really academy ratio (1.37) that are either hard or soft matted to the 1.85 ratio. Pretty much any anamorphic transfer that doesn't have any black bars on the top and bottom to preserve the original 1.85 ratio does this.

[Keiyakusha]

Gokumon
I mean if film originally 1.85 (http://www.petaimg.com/u388/4801.jpg), it can be letterboxed (http://www.petaimg.com/u6/8352.jpg), but it can be cropped (http://www.petaimg.com/u362/2093.jpg) before mastering too. I even saw cropped (or maybe pan&scanned) to 4x3 release.

EDIT: Oops, didn't saw your update.

[Ghitulescu]

In real cinema the things are (were?) very simple: the projectionist received the roles and the mattes together (maybe he was also told to change the lenses).

For TV , all these should have been packed into a TV standard.

Have a look here: http://lipas.uwasa.fi/~f76998/video/conversion/
or, if too complicated, maybe here:
http://forum.videohelp.com/topic345044.html

The real reason for all this "technical non-sense" was the marketing.

[newuserxyz]

I still don't understand how 720 / 522 = 16:9 (720x405 ???, 768x432 PAR=1 or 720x432 PAL).

The math is:
720 * 1,4222 / 552 = 1,85; Aspect Ratio video
720 * 1,4222 / 576 = 1,78 (16:9), Aspect ratio frame on dvd
576-552 = 24; 12 lines letterbox on the top and bottom
:cool:

[Ghitulescu]

http://forum.doom9.org/showthread.php?t=111102
Seems to contain the info you need ...

and
http://forum.doom9.org/showthread.php?s=&postid=562532#post562532