[PD] Gem Crashing On Ubuntu 19.04 with pix_video

[Jim Ruxton]

I recently updated a bunch of software so I am not sure at this point 
what is causing this instability. I went from Ubuntu 18.04 to Ubuntu 
19.10 and PD 0.49 to PD 0.50 . Gem is version 0.94 . Previously when I 
selected a device that didn't exist in the pix_video help file I would 
just not get any output in the Gem window. Now if I select a device that 
doesn't exist for example device 2 when only my laptop camera exists PD 
hangs up. I am not clear why but when I send an enumerate message to 
pix_video if no external camera is selected I get 2 devices ie.

info: device /dev/video0 v4l2
info: device /dev/video1 v4l2

If I add a USB camera I get 4 devices:

info: devices 4
info: device /dev/video0 v4l2
info: device /dev/video1 v4l2
info: device /dev/video2 v4l2
info: device /dev/video3 v4l2

Previously before upgrading I would select device 0 for my laptop camera 
and device 1 for a USB camera. Now I have to select 0 for my laptop 
camera and device 2 for an external camera. I can live with that but the 
fact that it hangs up if I send the wrong device number is a bit 
worrisome. Any thoughts on what is going wrong here and how I might fix 
this.

Thanks,

Jim