Jerky render of slow-mo clips

sellavision wrote on 5/4/2011, 11:26 AM

When I render in MOV format, clips I have applied slow-motion to are jerky in the final file. Is this normal (not acceptable !!) or am I doing something wrong in the render settings ? Thanks

Comments

Chienworks wrote on 5/4/2011, 12:18 PM

How much are you slowing down? How jerky is it? Is it very regular or is the jerkiness variable?

Your camera only shoots a certain number of frames per second. If you slow it down to 1/4 speed then you'll end up stretching each frame out to be 4 times as long and you will only have 1/4 as many frames per second. So if you're seeing a very regular jerk then it's quite normal. You could enable resample to try to smooth out the motion but Vegas does this by blending frames together making very blurry transitions.

johnmeyer wrote on 5/4/2011, 1:03 PM

Here's a sample I posted a long time ago of what slow motion looks like if you slow WAY down (1/8 normal speed) using two different settings in Vegas: "resample on" and "resample off" (in the Event Properties dialog). I also did the same slowdown using an external motion estimation plugin:

There is only so much that can be done by simply blending (resample enabled) or repeating (resample disabled) frames (or fields) when you slow down by more than 50% (1/2 normal speed).

sellavision wrote on 5/4/2011, 6:19 PM

Only slowed down about 10 percent......Made a 5 second clip around 6 seconds....

Laurence wrote on 5/4/2011, 6:29 PM

John Meyer, the MV Tools one looks great except for the cap tassel. Wonderful everywhere else. I suppose that it would be about the same with Twixtor (just a lot more expensive!).

johnmeyer wrote on 5/4/2011, 8:33 PM

John Meyer, the MV Tools one looks great except for the cap tassel.Laurence, you've got sharp eyes. That tassle was my one disappointment with that clip. I could have spent more time and tried a few different settings. Sometimes such problems can be reduced. The other thing I do sometimes is to also do the slo-mo in Vegas, put that on a lower track, and then create a mask around the area in the MVTools slo-mo that is failing. The blended slo-mo never looks great, but it usually doesn't look that bad either. By contrast, MVTools produces slo-mo that is like the little girl with the little curl.

Laurence wrote on 5/4/2011, 9:00 PM

"and when she was good she was very, very good, but when she was bad she was horrid." ;-)

johnmeyer wrote on 5/5/2011, 12:19 PM

Yup. And no less a poet than Henry Wadsworth Longfellow wrote it!