Pixel Aspect Ratio, DVD?


#1

ok guys, so i´m totally lost with this.
I´m making a animation for export to DVD. I output in Cinema with a resolution of 720x576, film format automatic 720x576 and pixel aspect ratio 1, and save avi format uncompressed. The thing is that when i export this to Sony DVD Architect, (where i have defined a pal project 720x576) my animation doesn´t fit the entire area, and i get two black side bars.

Ok, so i tried to put 1.07 pixel aspect ratio. The outcome is exactly the same.
What am i doing wrong?? Help, anyone?
Thanks in advance


#2

use 1:1 pixel aspect ratio and render to 720*486 (for NTSC)


#3

576 * .9 = 518.4
so you shoud render 720*518.4
Since you’re using PAL I assume this would work… but the decimal point is what’s throwing me off, so maybe round up to 519

BTW I’m posting here also (appart from the PM) so other members can comment , maybe correct me if I’m wrong.


#4

Hmmm, this sounds really wierd to me. Sometimes you do get this kind of problems if you dont render at true pixel ration…

So, my thought would be: render out still images (TGA for example), at the true PAL pixel ratio (1.07) and then import it to something like after effects, and then render it out to uncompressed *.mov file at the same pixel ratio. Why *.mov? Couse it is still a standard and just maybe there is something wrong with *.avi… and because you have to try something else if your way of doing fails at some stage:).

Hope it help. And would like to hear what was wrong.


#5

Try 720x576 with 59:54 pixel aspect when rendering.


#6

I always render my animations to PAL D1 720x576, film format: automatic, pixel aspect ratio: 1:1.
I never noticed any distortion because i always process my animations in Adobe Premiere and it rescales the images or movies to full screen. When i export the premiere project to .m2v (mpeg2) and import it into DVD Architect or Adobe Encore it fills the entire screen.

After reading your post i’ve tried to import a single image into DVDA and it has some black borders on the sides. I’ve tried the same with Adobe Encore and it doesn’t (it rescales the image to fit), except if i use the image on a menu, in a menu encore also leaves the black bars on the sides.

I’ve done some testing and i’ve came to the following conclusions:

PAL format is 768x576 (1:1) and not 720x576 (1.067:1).
What happens is that when you use 720x576 you have to use that weird aspect ratio because your images will be rescaled to fit the tv screen.

I’ve done some tests with a sphere in the centre of the screen:
A - Render to 768x576 1:1 - the tv displays a perfect sphere
B - Render to 720x576 1:1 - the tv displays a distored sphere
C - Render to 720x576 1.067:1 - the tv displays a perfect sphere

So i think the 1.067:1 aspect ratio is there to correct the rescaling.
If you divide 768 / 720 = 1.0666666666666666666666666666667
That’s the trick!

Possible solutions to your problem:

  1. Render at 768x576 1:1 (it will take longer, more pixels to render).
  2. Render at 720x576 1.067:1 and rescale it (premiere, after effects, whatever…) before importing to DVDA.

#7

I think twilight has explained it very well. I don’t know your dvd authoring software, but I would think it would work to a 720x756 format as a default. Almost all digital video software works to the 720x576 format when working in PAL. The 1.067 pixel aspect ratio is standard to that 720x756 format. It is called D1 PAL generally.


#8

Thanks guys.

Twilight:
This thing is a terrible headeach! You´re right about what you said.

My conclusions:
I render at 720x576 D1 Pal with 1.067 (this proportion gives the “extra” real width because PAL TVs are 4:3 in proportion,and 720:576 is not 4:3) But, like you said also, DVD architect doesn´t understand this, and i still get this side bars! It´s like as if it ignores the pixel ratio information (this is probably what happens). It´s the same when i put in c4d the 1.07 aspect ratio or not.

So i´ve tried Premiere Pro, wich now outputs to dvd (mpeg2 format) et voitla, i put this in DVD Archithect and now everything is ok. No Side bar.

Now, the strange part is that whether or not i render with the 1.07 aspect ratio (720x576 D1 Pal), if i import in After Effects it reads it with the 1.07 ratio. The thing is, that AE probably streches the video when no 1.07 ratio is present and this results in bad quality!!! You can note this very well if you have straight lines, that get all jagged up.

So, Lessons learned:
Render 720x576 Pal D1 with 1.07 aspect ratio.

  1. This way, my video has the same resolution as my Pal video projector
  2. No black side bars (the 1.07 ratio in the pixels fills the “missing space”)
  3. No quality loss in After Effects (or whatever) due to “streching”

Thanks once again everyone. Hope this helps future headeaches.
Luis C.


#9

http://imashination.com/tv.html


#10

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