To stabilize just a portion of a shot just set an in and out point. If I am using warp stabilizer the only thing in the composition is the shot I am stabilizing. Once stabilized that shot is rendered to a production format if the shot is more than a couple seconds long or the composition is nested in another comp to complete the shot. Warp stabilizing will dramatically increase the file size of your AEP. That is why most of the time I will work stabilize and render a DI (digital intermediate) using a suitable 10 bit or better production format.
How long is your shot? Warp stabilizer uses up memory and resources very quickly. A lot of shots only stabilize in a few sections. You should only be trying to stabilize the portion of the shot that is going to end up in the final edit. If the shot is really long and you absolutely need all of it stabilized then you may have to cut it into sections that overlap and find matching frames.
The other stabilizer that comes with AE does not smooth out handheld shots, it stops a tracked object from moving on the screen.
To better help you with your project please give us some details on exactly what you're trying to do. Please describe the shot or show it to us. You cannot warp stabilize a handheld shot of a crowd leaving the football stadium because everything is moving in different directions. You're going to need to have fixed geometry in most of the frame to use the warp stabilizer.
These clips are a minute or two 4K. Yes they are hand held concert crowds.
So far they have stabilized better than I expected. I thought AE had more better
stabilization tricks. I wanted to just sample a few seconds to decide. In the past,
I wasn't able to confine the stabilizing to any selection and then that ram preview
was going nuts and I couldnt even preview a section of the clip; all the clip or nothing.
So I gave up and used PPRo. Sometimes I have fixed geometry, but the lights go out and
fouls that up.
So can we restrict rendering effects in AE to just a portion for evaluation?
Must I bring in only a little clip in the first place? I rather bring in the
whole and select parts for different effect samples. How please?
Do you mean portions in time or do you mean portions in a frame?
As Rick says, you can trim your clip and apply the warp stabilizer to that smaller clip.
so i cant just select a portion of the timeline to restrict the effect to for testing?
Stabilizing always runs from the in point to the out point of a layer.
so can I set that? How?
Alt/Option + [ sets in point, Alt/Option + ] sets out point