Anamorphic DVD Menu? at DVinfo.net

Jack Robertson · February 18th, 2004, 10:56 PM

Hi all,

Working in PAL, I know the frame size is 720 x 576 pixels for creating 4 x 3 menus, but if I was to create a menu which was 16 x 9 (anamorphic) what size would the menu have to be?

Or would the frame technically still be the same size, but squeezed in someway?

Any info would help.
Cheers,
Jack

Rob Lohman · February 19th, 2004, 05:59 AM

I think you are confusing a couple of things here. The *FINAL*
framesize (for PAL) will ALWAYS be 720x576. Whether or not the
input is 4x3 or 16x9.

To get a correct 4x3 image to use for a menu you would import
a 768x576 (1.067 PA) or 786x576 (1.0926 PA) image (depending
on which pixel aspect you find matches closest) into the
authoring package or if it wants the final size create the image at
that resolution and then resample it down to 720x576 (without
maintaining aspect ratio!) before importing.

Now with widescreen you have a pixel aspect of 1.4568 (according
to Vegas -> the NLE I'm using. Other NLE's are probably using
a slightly different number). So that would mean that a picture
at 1.0 pixel aspect should be 1049x576. Import that into your
authoring package or resample it down to 720x576 (without
maintaining aspect ratio again) and import that.

This should do the trick.

Julian Luttrell · February 19th, 2004, 07:31 AM

Rob,

Vegas' calculator seems a little off - square pixel 16x9 PAL corresponds to 1024 x 576 (1024 divided by 576 = 16 divided by 9, see?).

Julian

Rob Lohman · February 20th, 2004, 05:49 AM

Julian: I know that's what all the other packages are using. In
other words, they are using a 1.422 PA for widescreen PAL. So
720 x 1.422 = 1024 as well. Vegas is using different numbers.

I've done a little bit of research and it looks like Vegas is using
the original numbers as it was meant to be. Therefor they also
claim they are the only one using the correct numbers. I found
something that seems to conform this claim, but everybody else
is using different numbers.

So that's a bit of a "weird" thing. As said in my previous post,
the numbers that I used came from Vegas. If you are using a
different package stick to 1024x576 indeed.

Jack Robertson · February 20th, 2004, 06:19 AM

Thanx for the tips guys, I knew there had to be a slight catch and a mathematical explanation for this.

I'll do some testing and see how it all looks. In my case I use Photoshop/Premiere/AE to edit and TMPGEnc to encode, I haven't really settled on an Authoring package, but I might try out Encore DVD.

Cheers,
Jack

Julian Luttrell · February 20th, 2004, 06:50 AM

Rob,

at the risk of being a techie bore...

Vegas' figures for PAL wide screen pixel aspect ratio of 1.4568 means they think there are 704 x 576 PAL 16:9 pixels in a widescreen frame. This is wrong.

[maths: each pixel is 1.4568 times wider than it is high, so a 16:9 image consisting of 576 lines will be w pixels wide where: 1.4568 x w / 576 = 16 / 9. This gives w = 703 (or 704 allowing for rounding errors)]

This strange 704 number actually originates from the NTSC world, where (for some reasons better known to those who are never the same colour) they have TWO different standard definition digital frame sizes: 704x480 and 720x480. I never worked out when each is used, but there you go.
PAL doesn't have the same problem.

Your 1049 number comes from multiplying the 704 pixel aspect ratio by 720 - a mistake I'm afraid.

The size to use is easy to calculate without EVER getting involved in pixel aspect ratios!
With square pixels as used in Photoshop (until recently), the ratio of the number of pixels across to the number of pixels down must be the same as the ratio of the frame width to frame height (=16 by 9). So w / 576 = 16 / 9 giving w = 1024.

Regards,

Julian

Rob Lohman · February 20th, 2004, 06:54 AM

We are on the same line here Julian. I don't understand either.
But when I brough it up sometime earlier it was claimed that it
was correct and everybody else was wrong and I was challenged
to prove this (that will be very hard to do, since all the numbers
are based on others).

I just gave the calculations based on numbers I found in the
NLE (and in my second post also for the rest of the NLE's).

Even the numbers for NTSC are off in Vegas from the rest of the
world!

February 18th, 2004, 10:56 PM	#1
Jack Robertson Regular Crew Join Date: Jun 2003 Location: Sydney, Australia Posts: 125	Anamorphic DVD Menu? Hi all, Working in PAL, I know the frame size is 720 x 576 pixels for creating 4 x 3 menus, but if I was to create a menu which was 16 x 9 (anamorphic) what size would the menu have to be? Or would the frame technically still be the same size, but squeezed in someway? Any info would help. Cheers, Jack

February 19th, 2004, 05:59 AM	#2
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	I think you are confusing a couple of things here. The FINAL framesize (for PAL) will ALWAYS be 720x576. Whether or not the input is 4x3 or 16x9. To get a correct 4x3 image to use for a menu you would import a 768x576 (1.067 PA) or 786x576 (1.0926 PA) image (depending on which pixel aspect you find matches closest) into the authoring package or if it wants the final size create the image at that resolution and then resample it down to 720x576 (without maintaining aspect ratio!) before importing. Now with widescreen you have a pixel aspect of 1.4568 (according to Vegas -> the NLE I'm using. Other NLE's are probably using a slightly different number). So that would mean that a picture at 1.0 pixel aspect should be 1049x576. Import that into your authoring package or resample it down to 720x576 (without maintaining aspect ratio again) and import that. This should do the trick. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

February 20th, 2004, 05:49 AM	#4
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Julian: I know that's what all the other packages are using. In other words, they are using a 1.422 PA for widescreen PAL. So 720 x 1.422 = 1024 as well. Vegas is using different numbers. I've done a little bit of research and it looks like Vegas is using the original numbers as it was meant to be. Therefor they also claim they are the only one using the correct numbers. I found something that seems to conform this claim, but everybody else is using different numbers. So that's a bit of a "weird" thing. As said in my previous post, the numbers that I used came from Vegas. If you are using a different package stick to 1024x576 indeed. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

February 20th, 2004, 06:19 AM	#5
Jack Robertson Regular Crew Join Date: Jun 2003 Location: Sydney, Australia Posts: 125	That explains it! Thanx for the tips guys, I knew there had to be a slight catch and a mathematical explanation for this. I'll do some testing and see how it all looks. In my case I use Photoshop/Premiere/AE to edit and TMPGEnc to encode, I haven't really settled on an Authoring package, but I might try out Encore DVD. Cheers, Jack

February 20th, 2004, 06:50 AM	#6
Julian Luttrell Regular Crew Join Date: Oct 2002 Location: Cambridge, UK Posts: 164	D!/DV and PAL/NTSC Rob, at the risk of being a techie bore... Vegas' figures for PAL wide screen pixel aspect ratio of 1.4568 means they think there are 704 x 576 PAL 16:9 pixels in a widescreen frame. This is wrong. [maths: each pixel is 1.4568 times wider than it is high, so a 16:9 image consisting of 576 lines will be w pixels wide where: 1.4568 x w / 576 = 16 / 9. This gives w = 703 (or 704 allowing for rounding errors)] This strange 704 number actually originates from the NTSC world, where (for some reasons better known to those who are never the same colour) they have TWO different standard definition digital frame sizes: 704x480 and 720x480. I never worked out when each is used, but there you go. PAL doesn't have the same problem. Your 1049 number comes from multiplying the 704 pixel aspect ratio by 720 - a mistake I'm afraid. The size to use is easy to calculate without EVER getting involved in pixel aspect ratios! With square pixels as used in Photoshop (until recently), the ratio of the number of pixels across to the number of pixels down must be the same as the ratio of the frame width to frame height (=16 by 9). So w / 576 = 16 / 9 giving w = 1024. Regards, Julian

February 19th, 2004, 07:31 AM	#3
Julian Luttrell Regular Crew Join Date: Oct 2002 Location: Cambridge, UK Posts: 164	Rob, Vegas' calculator seems a little off - square pixel 16x9 PAL corresponds to 1024 x 576 (1024 divided by 576 = 16 divided by 9, see?). Julian

February 20th, 2004, 06:54 AM	#7
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	We are on the same line here Julian. I don't understand either. But when I brough it up sometime earlier it was claimed that it was correct and everybody else was wrong and I was challenged to prove this (that will be very hard to do, since all the numbers are based on others). I just gave the calculations based on numbers I found in the NLE (and in my second post also for the rest of the NLE's). Even the numbers for NTSC are off in Vegas from the rest of the world! __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors