I've uploaded mjpg-streamer release 2016.2.0 to the ipkg repo, which will allow you to pass the following settings to the input plugin (via the INPUT[1] line of /etc/default/mjpg-streamer):
Code:
Optional parameters (may not be supported by all cameras):
[-br ].................: Set image brightness (auto or integer)
[-co ].................: Set image contrast (integer)
[-sh ].................: Set image sharpness (integer)
[-sa ].................: Set image saturation (integer)
[-cb ].................: Set color balance (auto or integer)
[-wb ].................: Set white balance (auto or integer)
[-ex ].................: Set exposure (auto, shutter-priority, aperature-priority, or integer)
[-bk ].................: Set backlight compensation (integer)
[-rot ]................: Set image rotation (0-359)
[-hf ].................: Set horizontal flip (true/false)
[-vf ].................: Set vertical flip (true/false)
[-pl ].................: Set power line filter (disabled, 50hz, 60hz, auto)
[-gain ]...............: Set gain (auto or integer)
[-cagc ]...............: Set chroma gain control (auto or integer)
Additional notes can be found
here.