FFmpegthumbnailer is a lightweight video thumbnailer that can be used by file managers to create thumbnails for your video files. The thumbnailer uses ffmpeg to decode frames from the video files, so supported videoformats depend on the configuration flags of ffmpeg.
This package contains the ffmpegthumbnailer executable.
Not bad, but it seems doesn't work fine for Matroska files. Thumbnails for mkv video files are often not generated. Either it's a kind of bug or it requires some certain configuration.