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Optical flow, say it isn’t so, long to render, that is…
Hey,
I have never used Motion much, but the new integration is making me think twice, but…
I took a short DV SD clip and slowed it down to 20% in FCP 6. Sent it to Motion for Optical Flow, total clip is 6 seconds. No problem, until the progress bar says 1100 or so frames to render, 1 hour 20 minutes! Excuse me? I could do this in AE in about 20 minutes tops.
This is running on a Dual 2 GIG G5 with 4.5 gigs of RAM, and a Radeon X 800XT card. An hour and 20 minutes? How much faster would this go on a Quad, and with what card?
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9 Replies
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It is pretty slow… think about what it’s doing and you’ll get why… making new frames from betwen two originals isn’t a task that isn’t pretty demanding, right?
Get thee to an octo…
Jerry
Apple Certified Trainer
Author: “Jerry Hofmann on Final Cut Pro 4” Click here
Dual 2 gig G5, AJA Kona SD, AJA Kona 2, Huge Systems Array UL3D
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[Jerry Hofmann] “making new frames from betwen two originals isn’t a task that isn’t pretty demanding, right?”
Just imagine doing it by hand and the render won’t seem so slow…
David Roth Weiss
Director/Editor/Post-production Supervisor
David Weiss Productions, Inc.
Los Angeles -
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Just saw a tut the other day about optical flow over at pixel cor ps.
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Tried to post a link but it got block. Just type the name in and it should come up.
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It’s always a good idea to read the manual…
Motion will have to analyze the whole movie file for the section you want to retime, so if you’re retiming a 6 seconds subclip of a longer movie clip then it will analyze every frame.
If the clip is only 6 seconds there should only be 150 (pal) frames to analyze.
Workflow is the following:
Set in and out points on clip to retime in viewer.
Select File: Export : Quicktime Movie
Make sure recompress all frames and make movie self contained are deselected
Import the resulting QT movie and drop on timeline
Set speed – deselect frame blending
Send to motion
Go to clip proerties, select timing: frame blending : optical flow.
Wait for it to analyze movie (a 6 sec clip takes about 8 minutes on my MB Pro)
Save and jump back to FCP
render and off you go.
Write 400 lines. “I will read the manual, I will read the manual, I will read the manual”
Good luck!
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Of course I will read the manual. I just got this 2 days ago FCOL. I did know this “whole clip” thing from reading about Smoothcam, didn’t put the 2 together, but this helps a lot, thanks.
BTW, I let that darn thing render over dinner, and the result is really weird, It is a shot of kids playing soccer, and in the foreground the goalie passes across frame rapidly, in regular motion it is quite blurry. Optical flow did an amazing job on it, but there are artifacts in front of the boy that used to be motion blur which now looks like there’s water being pushed in front of him. It’s similar to a ripple dissolve, but not regular, it follwos his form. If it wasn’t a mistake, I’d call it a cool effect, but I’m just wondering…
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VERY cool, thanks Craig.
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[Chris Poisson] “If it wasn’t a mistake, I’d call it a cool effect, but I’m just wondering…
“That’s the nature of the optical flow. The same things happens in the superior Twixtor plug in. When you understand how optical flow works, it makes sense. You have to remember that this process creates new media that wasn’t there before so there might be some weirdness in some areas. Twixtor has some settings to dink with to try and minimize, but even then it can sometimes get a little funky. It really depends on the footage and what’s happening in and around your subjects.
Jeremy
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