PhotoStructure has a ton of file filter patterns and heuristics to prevent unwanted photos and videos from being imported into your library. You may be fighting with one of those filters.
There are a couple ways to debug this.
-
Use
./photostructure sync --force --debug /path/to/video.mp4
and look for a log entry that explains why it’s skipping or failing to process your video. -
switch to the alpha branch, which includes “sync reports”, and run the above command, and instead of scrutinizing many screenfuls of log messages, just open the report and see the reason.
Here are a couple relevant pages: