WebUI: Set V4L device input

[Thinner77]

Feature request

What problem does this feature solve?

Setting the V4L device input (Composite/S-Video) in Web UI, currently device input 0 (Composite) is set and can't be changed.

What does the proposed API look like?

I don't know

How should this be implemented in your opinion?

restore original code

Are you willing to work on this yourself?

Maybe, a log-level "Trace" there all functions log there begin and end would be nice and helpfull to get knowledge of code flow. grabber.js seems to be a good starting point, but it doesn't get loaded in Firefox Developer Tools (F12)

[awawa-dev]

For old analog grabbers I think you can set it like PAL or SECAM using v4l2 tools #423
Currently, I do not plan further development in this direction.