You might try NFC for this rather than a camera. A usb reader/writer is $30-50, the stickers are $0.30 each. You probably want a dvd shaped fixture to place the case into to make sure it always lines up for a 5 year old, but that will work way better than optical recognition at the expense of having to set up each nfc tag, but that's something that was going to have to happen anyway for recognizing a physical movie cover.
You might try NFC for this rather than a camera. A usb reader/writer is $30-50, the stickers are $0.30 each. You probably want a dvd shaped fixture to place the case into to make sure it always lines up for a 5 year old, but that will work way better than optical recognition at the expense of having to set up each nfc tag, but that's something that was going to have to happen anyway for recognizing a physical movie cover.
NFC handlers are out there and easy enough, but getting it to launch Jellyfin into a specific movie is going to be on you to figure out. Here's a guy that was trying to do something similar with Home Assistant, but doesn't seem to have any traction on the board. That said, I did a very shallow dive so there might be better news elsewhere: https://community.home-assistant.io/t/jellyfin-integration-and-sending-commands-to-play-movie-to-tv-running-the-app/447937