HD in Combustion causing the jitters
by Nick Green
on
Nov 5, 2008 at 2:01:36 am
Hello,
I was wondering if anyone can help me out with this problem I ran into today. Long story short, I am working on an HD project in combustion. 1500X675/24fps/progressive footage(Custom for client)
Basically what is happening is that when I render the footage out, I am getting these Jitters. It almost appears to be an interlace problem but I have debunked that. I ran the same footage in After Effects and it ran great, no problems.
Here is the kicker, as I was performing Trial and Error, I found out when I decrease the size of my comp to NTSC, the jitters go away. It seems that Combustion's HD is not up to par yet. I talked to a buddy of mine and he gets the same problem when dealing with Normal HD settings and size. Can anyone help?
Recap:
1500X675 (Happens with Normal HD size as well)
24fps
progressive footage
All settings are correct in Combustion, and have tried every possible setting.
Re: HD in Combustion causing the jitters by greg gilpatrick on Nov 5, 2008 at 2:37:23 pm
I and others use HD in Combustion every day without issue.
I wonder if you're opening the footage into a composite with settings that don't match your footage. Use the Open command and select your footage and choose "2D(or 3D) Composite" to create a composite that match your footage's settings.
Re: HD in Combustion causing the jitters by Nick Green on Nov 5, 2008 at 7:27:09 pm
Thanks Matt and Greg.
I am not quite sure how to post a .mov. Can you help?
Just to reiterate, all settings in Combustion are to spec. The size of the assets are 1500X 675 and so is the comp. I even opened a regular 1080/24p just to see if I would get a different result, but it came out the same. But now when I dropped the comp to 720X 486, the jitters went away. The elements given were created 1500X675 24fps progressive. The elements that jitter are vector art. My backgrounds and the talent that I am using are still, they don't jitter. Could this be Graphics card issue?
I am using NVIDIA Quadro FX 3500. Combustion 4.
Thanks again and let me know how I can post a little quicktime for you guys to view.
Re: HD in Combustion causing the jitters by Dean DeCarlo on Nov 5, 2008 at 11:44:21 pm
If the jitters are in fact some type of field issue make sure that your footage operator is set to No Fields and that all composites (nests etc.) are also set to No Fields. Finally render using No Fields in the render dialog.
Can you playback the footage in Combustion without jitters? If so, then Quicktime is most likely the culprit. When selecting Quicktime output be sure to check the frame rate in the Quicktime settings in the render dialog. It must match your composite frame rate or Quicktime will automagically time convert your footage. Thanks for that Apple. I know several FCP editors that still don't get this. You should try a render to an image sequence (png, tif, tga) and see if that looks ok. Quicktime adds another level of uncertainty and should be avoided unless you really know what you are doing and have to use it.
Re: HD in Combustion causing the jitters by Dean DeCarlo on Nov 5, 2008 at 11:46:35 pm
I just re-read your last post. I guess the term "jitters" is a little vague. Are you rendering at Best quality? Otherwise there won't be anti-aliasing applied to moving objects or vector art.
Re: HD in Combustion causing the jitters by Nick Green on Nov 6, 2008 at 4:37:22 pm
As I said before, everything is what it needs to be. I have been using Combustion for many years and have never had to write a posting or came into a problem that I couldn't solve myself. The jitters happens through the play back, the ram preview and also rendering to Targas, PNGs and quicktimes.
My buddy worked on an HD honda spot and came into the same problem. The car jittered but everything else in the scene stayed still. It really seems like a field issue because how how it looks. But the composite is no fields along with the footage has no fields. Its all progressive.
Is there anyway that I can post a Qt to show you guys?
Re: HD in Combustion causing the jitters by Nick Green on Nov 6, 2008 at 8:37:46 pm
I am still trying to figure out this problem. Today I discovered that when I drop the quality to Medium or Preview, the jitters go away. Could this me an Anti-Alias bug?
Attached is an image that will help you guys understand my problem a little better.
In Combustion, create a new project with Dimensions of 1500 X 675.
No Fields/24fps/Square/20second duration.
Import this image attached. Zoom into 100% then press play. Look closely and you can see the jitters that I am talking about. Now drop the quality to preview. The jitters are gone.
Re: HD in Combustion causing the jitters by Nick Green on Nov 6, 2008 at 8:48:53 pm
One last thing, sorry I keep posting, but I think it will better my chances of figuring this problem out. I just discovered that when I change the 1500X 675 to 1500X 674 or 676, it fixes the problem too. It seems that it doesn't like odd numbers.
Re: HD in Combustion causing the jitters by Jeff Brown on Nov 7, 2008 at 1:53:32 pm
Yes, you have discovered the (long time) bug with antialiasing that Grant mentioned. The AA goes haywire with an odd-sized vertical dimension.
I had forgotten about that one; it's been a problem for years now. More evidence that Combustion is a forgotten child?
