I have refreshed the metadata, and this album folder still shows zero files in it, no thumbs or anything. It contains Quicktime .mov files. I have made sure the plugins are enabled for jplayer. This is on a vanilla, generic install of Zenphoto. Any ideas what the problem might be?

Thanks

You have to enable the the base class-video plugin so Zenphoto recognizes Quicktime files. jPlayer is not needed as it does not support them anyway.

Ok I enabled class-video, then refreshed the album and got this error:
Fatal error: Allowed memory size of 100663296 bytes exhausted (tried to allocate 104346353 bytes) in /zp-core/zp-extensions/class-video/getid3/getid3.php on line 1663

Is there a file size limit?

Thanks

There is no actual file size limit for the file system based albums itself. But this is a PHP server memory error because to read the meta data the whole video must be parsed. So the file is indeed too big probably.

Btw, I would really recommend to use mp4/m4v videos. Quicktime is ancient and very Mac specific video container and not natively supported by any browser.