#168 Zbarcam doesn't scan with option --nodisplay

[Revilo Reznik]

Hello,

if I try to start zbarcam with option --nodiplay reading of Barcode is not possible.
With graphic display the scanning works perfectly.

We see that in each case another video format is used.
In nodisplay mode format yu12 is used while in visible mode BGR3 is used.
Current version: 0.10.0
Raspi version: 4.9.31-v7+

Thanks in advance