camera: allow udp stream through ffmpeg

[Nyabsi]

This implements support for UDP protocol which I personally use to stream my GoPro Hero 5 to Project Babble,

if this isn't the desired way to do it, let me know!

[SummerSigh]

Hail and well met,

By the light of Eärendil's star, your code has traversed the dark forests of review and emerged into the clear skies of acceptance. Like Bilbo's party at Bag End, we find ourselves in a state of unexpected delight, for your contribution has proven as precious to us as the One Ring was to Gollum (though, fear not, far less perilous).

We've convened the Council of Elrond (our dev team), and after much deliberation that did not include throwing our keyboards into the fiery chasm from whence they came, we've decided to merge your pull request into the heart of our project, the repository of Middle-earth.

Your code, like Samwise to Frodo, has proven itself a faithful companion on this journey. You've navigated through the Mines of Moria (our codebase), faced the Balrog of bugs, and emerged victorious. We are as pleased to merge your request as Gimli would be in a mountain of axes.

May your keyboard be swift, your bugs few, and your commits as mighty as the Ents of Fangorn Forest. We look forward to your next adventure with us. Until then, let us walk the path of code together, under the watchful eyes of the, towards the undying lands of Production.

With the blessings of the Valar,

Summer
Keeper of the Code, Project Babble