Download suitable video from !YouTube. Find drone footage which moves through a space or around a prominent feature, such as a landmark or people who don't move much.
Create a folder to store your frames and copy the path to it. For Mac OSX/Linux users, this must be the full path (no ~).
Click Tools -> Preferences in VLC.
Under “show settings”, click “all”.
Under “Video”, select “Filters”. Tick “Scene video filter”.
Expand “Filters” and select “Scene filter”,
Paste the path from earlier into “directory path prefix”.
Decide what proportion of the frames you want to export. For example, if you want to export 1 in 12 frames, type “12” in the “recording ratio” box.
Click “save”.
Click Media -> Open Video and find your video. Patiently let the whole thing play.
Click Tools -> Preferences. Under “show settings”, click “all”. Under “video”, select “filters”. Uncheck “Scene video filter”. Click “save”. This is so that VLC won’t generate thumbnails the next time you play a video.
Open the folder you created earlier. The thumbnails should be there.
Import the sequence into PhotoScan and process as usually. If the video had many scenes I would process each scene as a 'chunk' in a master PhotoScan file.