[…] video stream to send over the internet must be encoded. Encoding needs lots more compute power.
… so I wouldn’t be too hopeful on that point. However I saw somewhere (not in this forum, maybe on Stack Overflow?) that we can take a local image (or video?) file and make Android (the post was specifically talking about WayDroid) believe it’s a camera. At least for QR codes for 2FA apps that should be enough.