Inconsistent Frame Size when rendered

XLA wrote on 10/15/2008, 3:56 PM
Hi all,

I'm having this weird problem when rendering. I'm rendering at 640x320 (reduced from 1920x1080) to speed up things. Now whats happening is that I'm selected an area of my clip and rendering..then another area a few seconds down and I get gaps on right and left sides of my output frame(s).

Whats happening? I know that I'm using mixed formats (ie. generated media, HD, some SD with output matching source..) but whats going on ?

I'm thinking that Vegas calculates its output based on the average frame size or something but bottom line is that i don`t get what I see consistently.

Thx for your feedback,
XLA

Comments

XLA wrote on 10/15/2008, 4:18 PM
Ok maybe whats happened is this:

I found my project set at 1440 x 1080 so I changed it to 1920 x1080. As a result certain elements became narrower. This made sense but I thought all my footage was in 1920 x 1080 until I checked the properties of a clip which showed 1440x1080..Anyways, Guess the best thing to do with mixed media is not change there properties pixel ratio but leave it and match output source otherwise it streches it out. Now, my generated media was probably created at 1440 so I had to unlock Maintain dimensions and expand the ratio to HD.

Anyways, I'm doing things on the fly because I've got a deadline but I'll check back to see if someone can enlighten the process a bit more .

XLA
farss wrote on 10/15/2008, 7:19 PM
Although your media might be 1440x1080 the frame size would be 1920x1080. The difference between the two is in the Pixel Aspect Ratio. Do not confuse PAR with Screen Aspect Ratio which for both 1440x1080 and 1920x1080 is 16:9.

Hope this helps rather than confuses but it's pretty import to get a good grasp on this stuff otherwise you get all manner of unsettling problems.

Bob.
Chienworks wrote on 10/15/2008, 7:28 PM
I would also suggest an output size of 640x360 instead of 640x320. 640x320 is 16:8, not 16:9.
johnmeyer wrote on 10/15/2008, 8:11 PM
We had a similar thread last spring. Here's a link to the middle of that thread where I provide some places you can go to get information on pixel aspect ratio, screen aspect ratio, etc. Once you read this, you will be able (hopefully) to understand how 1920x1080 and 1440x1080 can both produce exactly the same-looking picture, at least as far as the size and shape of how the picture looks on the screen.

My 640 x 480 video is clipped (cropped) on TV sets
XLA wrote on 10/16/2008, 9:02 AM
If I am cropping film on a green screen recorded 1440x1080, will it make a difference if the frame is not exactly the same ?
XLA wrote on 10/16/2008, 9:04 AM
(contd)
the same as the 1920 frame or must I Unlock, Change Focus, then reduce width to get size wanted.. ?