need help with jitter

ddb wrote on 7/19/2003, 6:29 PM
after rendering a video to save as avi file, there are parts of it that have some pretty severe horizontal lines along the outlines of contrasting objects during any kind motion on camera, i.e. around a person as they are walking, or a stationary object during a camera pan (during a print to tape, this translates into a jittery motion). It doesn't happen through the entire video, but I've re-rendered several times and it occurs at the same places each time. The raw video is clean, as well as no problem during preview. It seems to happen only during rendering. HELP!

Comments

TomG wrote on 7/19/2003, 6:58 PM
I just got through a bout with jitter (I think the pros call it judder but I'm not a pro)... My problem with in the frame order when rendering. The default for an NTSC DVD template is Interlace-bottom first. That usually worked for me but this last time, when I got all the judder, I had to change over to progressive (no interlace). That took care of it for me.

Good luck,

TomG
snicholshms wrote on 7/19/2003, 10:49 PM
Progressive is OK for playback on a computer but you'll need to render to either upper or lower first for VHS. To get rid of "jitter", right click on the video and select "Properties" Check "Reduce Interlace Flicker" and render.
mikkie wrote on 7/20/2003, 9:37 AM
"It seems to happen only during rendering"

If you don't see a problem on playback, probably don't sweat it. You can get info and pictures here of what it might be: http://www.zerocut.com/tech/pulldown.html & http://www.100fps.com/ - if it doesn't look like the examples, might have problems with field order reversed (should be the same ideally from clip to proj to render).

If your destination for the video is a std TV, you can either leave interlace in, or render progressive & let your output device establish or inset it if possible - many will. Changing frame rates will cause the prob, sometimes just digitizing or compressing the video can cause it - try changing some of your settings... On the timeline you can try splitting the clip at prob scenes/pans, then applying a bit of light blur and supersampling (might have to alter the clip a bit to get optimal results, i.e.: render a bad pan only to 1/2 your proj fps, import the result, have Vegas change the fps back to proj rate with supersampling on -> Vegas will generate missing frames with high accuracy, and motion should be smooth, though individual frames may not be as sharp).

ddb wrote on 7/20/2003, 5:40 PM
ok....clicking on 'reduce interlace flicker' seemed to have taken care of my problem. Now when I print to tape, it renders all but the last 4 minutes of video. It takes one scene (4 min from end of video) and uses that clip for the remaining 4 minutes instead of the remaining clips!
TomG wrote on 7/20/2003, 8:55 PM
Well, I learned something from snicholshms too. I thought I had to render in progressive but I went back and set the properties of my .avi file to "reduce interlace flicker" and rendered as interlaced and it did look fine when I burned the DVD.

One more question, since I split the heck out of my source file, is there any quick way to set all of the split pieces to "reduce interlade flicker?" Or do I have to do each piece by hand?

Thanks,
TomG