How to stabilize long videos?

Thank you all for the useful comments! 

I got your main points, I am aware that stabilization is not an easy job. However I had very good experiences with it from the past when I edited my 4K individual clips into a movie. I have never ever had problems runnig wrap stabilizer in parallel and it used all my 12 cores 100%. I never try to stabilize very shakky, fast etc. videos, I want to compensate some hand shake only.

However now when I have an edited long movie (it is only 1080p!) and I need to split to separate clips the wrap stabilizer works completely different. I cannot run in parallel (if I put 2 wrap stabilizer at the same time it slows down like crazy) I need to put them one by one and it does not even use 30% of my CPU resources.

So actually I am just curious why it works in a different way.

Warp stabilizer is not at all like in-camera stabilization. Think of what it does ...

• It internally plays through the clip, looking for reference points that stay in relative position to each other, or at least close.
• It marks all those reference points in order through the clip as they move.
• It plans a process to keep those reference points as stable as it can.
• It then analyzes how much it will need to crop/zoom-in on the image, to keep a full image frame throughout the clip.
• It sets that crop/zoom for the clip, then passes down the keyframes both moving the image position AND creating new frames at times as needed.

That's a very, very complex series of automated operations. And it was not designed as a replacement for camera operations using either "sticks" (tripod) or in-cam stabilization. It's a tool built to handle 'emergency' saves where you can't reshoot.

And the longer the clip, the more complex the operation becomes, and the more likely that you will not like the changes it decides to make. Especially as some types of motion coupled with types of image detail respond better visually to different adjustments of the effect parameters than others. And you may well need to adjust some parameters on some clips, and re-analyze.

In summary ...

• the shorter the clips, the better;
• watch all stabilized segements to see if they're usable as is;
• change parameters and re-analyze as needed.

And something I always recommend ... after you 'accept' the Warp work on a clip, REPLACE that clip with a full Render & Replace operation using a good intermediate intraframe codec like Cineform, ProRes, or a DNx variant.

Why? Because Warp is such a heavy effect, that if you try ANYTHING else like Lumetri color, video noise reduction, speed-ramping, any significant effect ... your playback and your export will be excruciatingly slow.

Warp ... render & replace ... then do any other effects needed to that replacement media.

Neil

Warp Stabilizer is very CPU intensive.

Don't do the lot in one go, just a few at a time.