A stream is generally of lower quality than a photo which should make it significantly more difficult to get a good scan of a QR code from a stream --- particul

A stream is generally of lower quality than a photo which should make it significantly more difficult to get a good scan of a QR code from a stream --- particularly if the code is changing every few seconds. I'd probably recommend showing a code for 3 seconds then a black screen for 3 seconds then repeat with a different code. Cameras need to focus on both ends and the stream has to be scaled to fit the available display parameters. Could easily turn into an exercise in frustration.