Please describe the problem:
If you open the directory where you download video files with bittorrent for example (so they are downloading), the thumbnails are regenerated every time the file changes : all the time.

So if you forget to close this directory when your torrent client is open, CPU is at 100% all the time.

Maybe it would be good to add a delay where a thumbnail is not regenerated (for example, if the file changes but the thumbnail has been generated less than 15s ago, it is not regenerated immediately). Or any other solution

Steps to reproduce:
1. open your torrent client
2. download videos
3. open the download directory in nautilus


Actual results:
thumbnails generation takes 100% cpu

Expected results:
shuold not be refreshed 15 times per second

Does this happen every time?
yes

Other information: