Aspect Ratio Question...

ADinelt wrote on 6/3/2004, 5:16 PM
If a screen with an aspect ratio of 4:3 has 720 x 480 pixels (for NTSC DV), does anyone know what the correct number of pixels would be for an aspect ratio of 16:9?

Does the width of 720 stay the same resulting in a height of 405, or would the height of 480 stay the same and the width change to 853.3333 or is it something else entirely?

Thanks in advance...
Al

Comments

Chienworks wrote on 6/3/2004, 6:48 PM
Something else entirely. Ideally the file will still be 720x480 with a PAR of 1.212121... This is only for true 16:9 though. Some cameras will cheat and record 16:9 by cropping off some of the top & bottom of the frame.
ADinelt wrote on 6/3/2004, 7:11 PM
Thanks Chienworks.

Not sure what a PAR is though. Could you elaborate on that?

Al
Chienworks wrote on 6/4/2004, 5:47 AM
"Pixel Aspect Ratio", which is the shape of the individual pixels, as compared to the more common useage of "Aspect Ratio" which often refers to the shape of the entire frame.

Yeah, it gets confusing. ;)
ADinelt wrote on 6/4/2004, 9:08 AM
Okay, not wanting to sound really dumb, but here goes...

1) I go into the Project Properties and select NTSC DV Widescreen for my Template.
2) I import a video clip which has a PAR of .9091 (NTSC DV).
3) The clip does not fill the frame completely and is slightly distorted, so I change the PAR in the Properties of the clip itself to 1.2121 (NTSC DV Widescreen). It now fills the frame and is no longer distorted.
4) Everything appears to be okay so far in the preview window.
5) However, when I try to render the clip to MPEG2, which template shoud I use? If I use DVD NTSC, then I get black bars above and below my video clip. There is a DVD Architect Widescreen video stream, but there is no audio when rendered (which is probably why it is called a video stream).

Thank you very much for your patience...
Al
allyn wrote on 6/4/2004, 1:01 PM
moviestudio doesn't render widescreen video to mpeg-2 in a useful way. you need to render using the DVD NTSC template and then use an external program like dvdpatcher (google for it) to set the correct 16:9 aspect ratio.
ADinelt wrote on 6/4/2004, 2:11 PM
Thanks allyn...

I downloaded a copy of DVDPatcher, but have not had a chance to try it yet.

Another question though.

Maybe I am missing something here (which wouldn't be the first time), but if I have a file in a 4:3 format with a PAR of .9091 and changing the PAR to 1.2121 causes the file to fill the screen in a 16:9 format, shouldn't there be some distortion? Or does changing the PAR cause the file to be clipped on top and bottom automatically?

Al

allyn wrote on 6/4/2004, 3:22 PM
i don't see how the PAR can be changed without causing distortion. the PAR needs to be set to whatever was used when shooting. if you have the wrong PAR you should see distortion.

i use 16:9 on my panasonic pv-dv953 and i use the NTSC DV Widescreen project properties. i think there is a checkbox that may need to be checked when rendering that says something like "use original aspect ratio".

then i render to mpeg-2 using DVD NTSC and use dvdpatcher to modify the aspect ratio of the resulting file from 4:3 to 16:9. then i burn using mydvd.

a little more tedious than should be necessary but it works great!
ADinelt wrote on 6/4/2004, 6:04 PM
Allrighty then...

Did some tests...

1) Created a bitmap image at 655 x 480. On it, I placed the alphabet across the top and down the left side. Also, I placed 4 perfect circles and two perfect squares (or at least as perfect as possible).

2) Created a project in SB using a NTSC DV Widescreen template.

3) Imported the bitmap and changed the PAR to 1.2121. The bitmap looked fine in the preview window and after rendering. However, when DVDPatch was used to put the MPEG2 file into 16:9 format, the image did distort. Looked like it was squashed vertically.

4) Put the PAR back to it's original default. Image looked squished horizontally in the preview window and when rendered. Looked fine after DVDPatch, but did not fill up the entire screen.

5) Used Pan/Crop to crop the top and bottom off the bitmap so it filled the screen. It still looked distorted in the preview window and when first rendered. Looks just fine after DVDPatch converts it to 16:9 format.

Long story short, it looks like I can take my 4:3 video and 3D models and create a 16:9 video. Bit of extra work, but I really like the look of widescreen videos.

Thanks to everyone for their help...
Al