[Milhouse]

I notice that if in Kodi, I simply view the artwork via Info/Choose art, then the thumbnail for the movie will show up in chorus. How can accomplish this with texturecache for all of my movies?

If the artwork is embedded, there's no way to force Kodi to cache the thumbnails automatically - you have to manually navigate through the Kodi GUI and Kodi will slowly extract the artwork from the video or music files, creating the cached thumbnail versions.

If the thumbnails are remote (downloaded from the internet) or local (stored alongside the video/music files) then texturecache.py c movies etc. should cache the artwork automatically (so long as the artwork is still accessible - remote artwork has a habit of disappearing).

You can determine if your artwork is embedded, remote or local by viewing the metadata for an item, eg. texturecache.py jd movies avatar - if the artwork path starts with video@ then it is embedded and cannot be automatically cached. If it starts with http or https, then it is remote.