ADOBE AFTER EFFECTS: Forum Expressions Tutorials Creative Cloud

Why are my fades jittery?

COW Forums : Adobe After Effects

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
Jeff Davis
Why are my fades jittery?
on Oct 7, 2010 at 2:58:12 am

I'm working on my first HD project, 1440 x 1080 @ 29.97 fps, full resolution. All of my fades are jittery, as if they were rendered at a lower framerate. I'm just fading opacity from 0% - 100%, or the other direction.

I'm using AE CS5 on Win7 x64 with 12 GB of RAM and a dual core Xeon CPU running at 2.3 GHz.

Thanks.


Return to posts index

Dave LaRonde
Re: Why are my fades jittery?
on Oct 7, 2010 at 3:17:59 pm

[Jeff Davis] "All of my fades are jittery, as if they were rendered at a lower framerate."

When exactly do you see this? When you play back the clip rendered out of AE, or in a RAM Preview?

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


Return to posts index

Jeff Davis
Re: Why are my fades jittery?
on Oct 7, 2010 at 3:35:47 pm

During playback of the rendered clip. It's actually fine during RAM preview. And I should say that pans and zooms display the same jitterines, again during rendered playback only.


Return to posts index


Dave LaRonde
Re: Why are my fades jittery?
on Oct 7, 2010 at 5:12:45 pm

What you see is absolutely normal. This is your first HD project, and you have to remember that you're dealing with 4-5 times the data per frame of a comparable SD picture.

You've probably rendered a high-quality file using AE, which is the right thing to do: you're preserving image quality, which you'll appreciate when you take the file into the NEXT application. The playback problem arises because your machine can't keep up with the much higher bit rate of an HD picture.

To reassure yourself that everything's fine, take that file into a COMPRESSION application, like Apple's Compressor, Adobe Media Encoder, or something similar. Make an H.264 file... and it doesn't have to be of very good quality. You're simply checking the motion. Play it back, and witness no playback in fits and starts, just nice, smooth motion.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


Return to posts index

Jeff Davis
Re: Why are my fades jittery?
on Oct 7, 2010 at 8:37:29 pm

Thanks for the explanation, but I'm already rendering to h.264 within After Effects. If I resize during the render to 960 x 720, the fades, pans, and zooms appear as they should during playback.


Return to posts index

Dave LaRonde
Re: Why are my fades jittery?
on Oct 7, 2010 at 8:43:08 pm

[Jeff Davis] "I'm already rendering to h.264 within After Effects."

That's a big mistake. Here's why:

Dave's Stock Answer #3:

Don't use AE to compress files for final delivery. The various compressors are there only to make quick 'n dirty files showing a project's progress to producers, clients, the kids, etc. AE is incapable of doing multipass encoding, a crucial feature that greatly improves the image quality of H.264 and MPEG-type files in particular.

Render a high-quality file from AE, and use a different application to do the compression. Popular ones are Adobe Media Encoder, Sorenson Squeeze and Apple's Compressor, which comes bundled with Final Cut Suite. Even compressing in Quicktime Pro is better than compressing in AE.





[Jeff Davis] "If I resize during the render to 960 x 720, the fades, pans, and zooms appear as they should during playback."

Sorry, I don't know how you resize something as it renders. Is this something new, or do you mean something else?

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


Return to posts index


Jeff Davis
Re: Why are my fades jittery?
on Oct 7, 2010 at 11:41:40 pm

Thanks loads for that rendering tip, Dave. It never would have occurred to me. Can't wait to try, but what output format do you recommend rendering to from AE if I want to do my final encoding in Adobe Media Encoder (which I have, unlike Sorenson or Apple's Compressor)?

Regarding "resize during render," if I add my comp to the render queue and select "Custom" for the output module, there's a Resize option on the Main Options tab in the resulting dialog. There it lets you resize height and width to anything you want, as well as standard resolutions and aspect ratios.

Jeff


Return to posts index

Dave LaRonde
Re: Why are my fades jittery?
on Oct 8, 2010 at 2:17:18 pm

I've NEVER used the Resize option. Not once. Not even to see what happens when I use it. I got advice long ago never to use it, and I don't.

Use Adobe Media Encoder to resize and do the compression. Since I don't know how your file will be used next, I can't be any more specific.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]