Final Cut stuck in 'Analysing for optical flow'

Anybody got a solution for the situation where you want to apply optical flow and FCP says it is analysing the clip but nothing happens.
Done the delete preferences and delete cache but no change.
I remember this being a problem for a long time but I never really found a reliable solution.
It happens right now on a synchronised clip in Proxy mode. Original is 4K XF-AVC wrapped in Quicktime container and proxy is Apple Proxy at 50%.
Thanks guys for any ideas.

If you have Final Cut Library Manager (Arctic Whiteness) you can delete the optical flow files for the library and then reboot and re-apply your optical flow. You can also drill down into the library package without any additional software (select library - control click - show package contents) and manually trash the optical flow files. Using FC Library Manager may be a safer and more thorough method, but manual deletion has worked for me in the past.

Thanks Dgwvideo!

Yes I drilled down into package or better the Cache as it is were the analysis files are and deleted them including the render files.

The problem is that even if I do that FCP shows the message on the clip 'Analysing clip for optical flow' but doesn't do anything?

Possibly a bug then. I think I may have seen that happen once or twice when manually removing files, but I usually use FC Library Manager to remove optical flow files and I don't recall seeing the "analyzing clip...." message after doing that.

I just figured out that it only happens with Synchronised clips. If I use the original video clip only it works fine. Will have to investigate that a bit further.

Hi Carsten

Did you ever find a solution for this? I am also stuck with it working fine on unsynced clips, but synced clips it just gets stuck, same with stabilisation....

"Open" the sync clips and do it inside, or better break it ! (il will remain in Sync - if you fear sync lost mark the clips video and audio

Stu Wart wrote:

"Open" the sync clips and do it inside, or better break it ! (il will remain in Sync - if you fear sync lost mark the clips video and audio

This is exactly the work around I have been using, but it isn't ideal. In previous projects it worked fine, but all of the sudden with the current it just gets stuck as described in earlier post.

Trying to get to the bottom of why this specific library is giving me these issues.

Sorry no I didn’t find a solution to the problem

This is somewhat related. For *some* flow transitions (not all…about 25% were affected) in a larger project I'm working on that exist within a compound clip, play fine in the compound clip, but when that compound clip is placed within a project FCP almost "frames" the clip (⅓ of the bottom and a third of the right hand side of the frame is made transparent, showing the clip behind/ the background in the project). I similarly have deleted all the render files, tried the Arctic Whiteness library manager too to delete the files… and everything fails. What I ended up doing was writing out the compound clip and then substituting that output for the compound clip… a real pain on a longer project.