We have a ticketing system where people actually buy tickets online. we want to add bar code facility in that which is mobile. so when someone books a ticket they receive mobile bar code as well or a qr code and when they come to the venue they just show their mobile and checkin .. and ofcourse only that person can check in.
remember we already have a solution so we need this extra bit within the system that we have in php.. we dont need entirely new system. if you have done this before please get back to me.