Movie save for avi in Windows doesn't work

[EricThomson]

Discovered during Discussion #1178 and related to problems with loading avi that was fixed in PR #1161.

Saving avi doesn't work in Windows (strangely, this functionality is in timeseries.py). It uses a similar OpenCV back end to load(), so shouldn't be too different a fix from the load problem.

I wonder why save() is not part of movies.py like load() is? Maybe not something to worry about now, but it seems like an unusual design choice to put it in a separate timeseries.py module. The movie object is an instance of timeseries object, as is trace, which I think is not used in caiman the way that the movie object is (though I haven't investigated thoroughly). If you tried to save a trace object using trace.save() my guess is it would not go well :smile: Maybe at some point we may consider leaving save() unimplemented in timeseries(), treating save() as a factory method, and move the details to the dependent object like movie(), as is done with load().

But for initial fix I think we can leave things structured as is.