Metadata for video

Now we are watching video on our telly via UPnP media server, it's rather annoying the server can't do any kind of sorting/grouping/filtering on video, similar to what it can do on audio files.

On audio files, I guess it's reading the embedded ID3 metadata to pull Album Names and Artists and allow filtering by those attributes. Images have EXIF and IPTC metadata formats. However, video files don't seem to have a corresponding metadata format. Why? Is it because the concept of a digital video library is relativley new?

An extension of the existing MP3 ID3 tags would probably work (ID4? IDvid?), tagging:
- Title (movie or episode name)
- Episode Num (if a series)
- Series Num/Name
- Director
- Genre (Sci Fi, Drama etc)
- Year Released
- Production Company (? Might be good for grouping up BBC stuff for instance)
- Language (for people that have multiple language stuff)
- Disk Num (ie for ripped DVD's or series?)

Or have I missed something that's already out there? Google couldn't really help me :(