The main reason I prefer Thunar over other open source file managers is because it currently has the best support for video thumbnails being the only app that can generate thumbnails for video files stored on network drives. I'd like to see Thunar take its support for video thumbnail previews to the next level by introducing custom video thumbnails. The problem this feature request addresses is that most file managers will usually use the first frame of a video as its preview. In many cases, this frame will be entirely blank and/or match several other videos within the same folder hence making the preview rather useless, especially if all the files have non-descript names too. This is where custom video thumbnails come in. The way I envision this working is that video thumbnails would get generated as they do now for all files in a folder but the user would be also be able to mouseover a video file in Thunar's Icons view mode (with thumbnail previews enabled) then, when holding a modifier key such as ALT, the user would be able to use either the mouse scrollwheel or the arrow keys to adjust/update the icon preview image of the video file under the cursor - every scroll/keypress updating the icon preview with a image a second forward or backwards into the video. This to me seems like a nicer workflow than having to rename the files to locate them easier.
Hi Dan, thanks for your request. What you want would not be implemented in thunar, but as a separate thumbnailing service that you could integrate with tumbler, our thumbnailing service. Tumbler already has support for video-covers, which get fetched from the interwebs (themoviedb iirc). You can look that up and enable it (I don't think any distro enables that out of the box because of privacy concerns). https://docs.xfce.org/xfce/thunar/tumbler#cover_thumbnailer