How to add title metadata to videos with AppleScript?

Moving to a Plex Media Server I realized a majority of my video archive doesn't have metadata and when I render the videos through Plex's UI I see Episode # when I want it to render as Episode Foobar. Per research (add new and non defined metadata to a mp4 file ) I found that ffmpeg can be used so I did a brew install ffmpeg and verified with a man ffmpeg it was present. Built my AppleScript to detect the volume, load the folder contents as a list, take the formatted name for plex, example: - Foo Bar -- Foo Bar - s01e01 - Into the Foo.mov -- Foo Bar - s01e02 - Into the Bar.mp4 Everything after s##e## - but before . as the title, such as: ffmpeg -i Foo Bar - s01e01 - Into the Foo.mov -metadata title="Into the Foo" Foo Bar - s01e01 - Into the Foo.mov I verify the title was modified with: ffprobe -v quiet -print_format json -show_format -show_streams Into the Foo" Foo Bar - s01e01 - Into the Foo.mov > result.json and under format I see: "format": { "filename": "Foo Bar - s01e01 - Into the Foo.mov", "nb_streams": 2, "nb_programs": 0, "format_name": "mov,mp4,m4a,3gp,3g2,mj2", "format_long_name": "QuickTime / MOV", "start_time": "0.000000", "duration": "652.342000", "size": "13507029", "bit_rate": "165643", "probe_score": 100, "tags": { "major_brand": "qt ", "minor_version": "512", "compatible_brands": "qt ", "title": "Into the Foo", "encoder": "Lavf58.12.100" } } but with a do shell on the quoted form. When I load it to Plex and run an update then run a Refresh Metadata the titles still render as: Episode 1 Episode 2 in AppleScript how can I properly add the metadata to read file title metadata on videos? Is there another approach to this I'm missing?