It can definitely be done but I don't know the details.

A couple times a year the local Half Price Books Outlet does a "fill a bag for $20" event and every time there are at least a couple people there with shopping carts full of bags of books.

They have dedicated bar code scanners attached to their phones and will scan books at around 1 a second. I don't know what software they are using but clearly they are looking up prices to see what they can get to sell for a profit.

I use goodreads to keep track of my own book collection and using the camera and the goodreads app usually takes 30 seconds plus to focus on the bar code and then to look it up. So whatever they are using is much faster than that.