Have not been successful with this, best Ive been able to do was add an image to just the thumbnail view of the file but otherwise just a horrible pictureless checkerboard placeholder shows throughout the file during playback
Edit: [used Shotcut] discovered if import the cover jpeg in with the other file(s) and drag it to the playback window (it will be checkerboard pattern if no image) it embeds the album art thruough the entire output file.


Does it have to be ffmpeg? If you need a CLI option, I ended up using eyeD3
Can be anything, whatever’s easiest and most reliable