How to rename a file with a leading hyphen?

[joe at actionline.com]

When I download images and ".MOV" files from digikam
the file names all have a leading hyphen. I've been
able to convert -filename.png files to filename.jpg
but when I try to use 'mv' to rename -filename.MOV files
to filename.MOV or filename.mov without the leading
hyphen, it does not work.

How can I rename these .MOV files to remove the leading
hyphen (-) and to change the .MOV suffix to .mov ?

Also, how can I convert .MOV or .mov files to a more
efficient file format that is not such a huge file?