Weird Interlacey problem

[Michael Duff]

” I interpreted the footage and set Fields and Pulldown to OFF and pixels to D1/DV NTSC (0.9)”

i could be wrong, but shouldn’t the footage from the beta be interpreted as upper? unless you have de-interlaced it before after effects. When you play the source clip in quicktime do you see the fields? if so, they will need to be interpreted

Michael Duff –
Bearcage Productions, Australia

[Matt Wafaie]

well, initially they were interpreted as upper. But the footage looked terrible. The edges were very blocky. Is that unusual?

M@

[Al]

no that’s not unusual, we all work with blocky edges 🙂 kidding; it sounds like a problem with what you’re rendering as rather than how you’re interpreting it. what’s your render setting?

[Steve Roberts]

If you drag a clip onto the new comp button, AE creates a new comp with the same settings as the clip. Dave is right — if you’re mixing BetaSP and DVCAM footage, one may be 720×486, and one may be 720×480.

If you expect to scale one clip or the other (you said “up-rez”?), you must interpret DVCAM as lower fields first (LFF), and Beta as LFF, but that’s an assumption for the Beta. To test, interpret the footage as LFF, then alt-double-click on it in the project window. Look at the window that comes up, and step through the footage with the pageUp/Dn keys. If the footage jerks back and forth as you keep tapping the same key, you’ve interpreted the footage wrong, and it should be UFF, not LFF.

If you just want the same clips in the same comp, with no scaling, no repositioning, no rotating and no blurring of the footage (all those will mess up fields) use a 720×480 comp and when you drag in the 486 clip, move it up one pixel. That will ensure its field order does not get reversed. You’ll crop off 2+4 pixels, but that’s cool.

Does any of that help?

[Matt Wafaie]

hmm, I am mixing the two because the footage I’m compositing in is HDV. Could this be screwing up the beta footage? That might explain why creating a new comp works fine. What can I do about this? Anything? I re-interpreted all of the clips LFF a while back and had no interlacing problems, but, if I do that I get a weird strobey effect on some of the clips. This whole thing is kind of a mess because I had no choice but to originate the media on mac and I’m doing all this on a PC.

[Steve Roberts]

Have you tried interpreting the Beta/DVCPRO as LFF (check it as I directed) then making an HDV comp and dropping the Beta & DVCPRO into the HDV comp?

When do you see the weird stobey effect? RAM previews? Playing on a broadcast monitor?

[Matt Wafaie]

It appears after being rendered out. I’m actually not sure if it’s visible during RAM preview or not. Maybe there is something I’m missing in interpretation or comp settings. Could it be a Pulldown problem? The beta footage originated on film and I used SSWWW. Perhaps this is the issue?

M@

[Steve Roberts]

You only need to remove pulldown if you want to work with complete frames at 23.976 fps. Otherwise, just separate fields (LFF most likely) and work in 29.97 fps.

[Matt Wafaie]

Cool, I’ll give that a shot. Thanks. Just out of curiosity, do you have any idea if this strobing effect could be a result of removing the pulldown at 30fps? What should happen to the video if you do what I’ve done and Remove Pulldown when you don’t need to?

[Steve Bradbury]

I