开放源代码条形码扫描器在C?

I'm looking for any open-source software out there that takes an webcam stream and scans for a barcode, returning the value of the barcode in the current frame, if any. It would be preferred if it was in C, but any other languages are welcome. Note, I am not interested in using a mobile phone or a separate barcode scanner. I'm looking for any open-source software out th