Fixing Linux Webcams
v4l2-ctl --list-devices
v4l2-ctl -d /dev/video0 --list-ctrls
v4l2-ctl --get-ctrl=white_balance_temperature
v4l2-ctl --set-ctrl=white_balance_temperature=4000
v4l2-ctl --set-ctrl=white_balance_temperature=4000 -d /dev/video0
v4l2-ctl --set-ctrl=white_balance_temperature_auto=1
v4l2-ctl --set-ctrl=white_balance_temperature_auto=0
v4l2-ctl --set-ctrl=white_balance_temperature_auto=4000
v4l2-ctl --set-ctrl=exposure_auto=3
v4l2-ctl --set-ctrl=exposure_auto_priority=0
v4l2-ctl --set-ctrl=exposure_absolute=250
v4l2-ctl --set-ctrl=exposure_absolute=0
v4l2-ctl --set-ctrl=exposure_absolute=250
v4l2-ctl --set-ctrl=gain=0
v4l2-ctl -d /dev/video0 --list-ctrls
v4l2-ctl --set-ctrl=white_balance_temperature_auto=4000
v4l2-ctl --set-ctrl=white_balance_temperature_auto=0
v4l2-ctl --set-ctrl=white_balance_temperature=4000
v4l2-ctl -d /dev/video0 --list-ctrls
This article is great: https://www.kurokesu.com/main/2016/01/16/manual-usb-camera-settings-in-linux/
v4l2-ctl -d /dev/video0 --list-ctrls
brightness 0x00980900 (int) : min=0 max=255 step=1 default=128 value=128
contrast 0x00980901 (int) : min=0 max=255 step=1 default=128 value=128
saturation 0x00980902 (int) : min=0 max=255 step=1 default=128 value=128
white_balance_temperature_auto 0x0098090c (bool) : default=1 value=0
gain 0x00980913 (int) : min=0 max=255 step=1 default=0 value=0
power_line_frequency 0x00980918 (menu) : min=0 max=2 default=2 value=2
white_balance_temperature 0x0098091a (int) : min=2000 max=6500 step=1 default=4000 value=4000
sharpness 0x0098091b (int) : min=0 max=255 step=1 default=128 value=128
backlight_compensation 0x0098091c (int) : min=0 max=1 step=1 default=0 value=0
exposure_auto 0x009a0901 (menu) : min=0 max=3 default=3 value=3
exposure_absolute 0x009a0902 (int) : min=3 max=2047 step=1 default=250 value=83 flags=inactive
exposure_auto_priority 0x009a0903 (bool) : default=0 value=0
pan_absolute 0x009a0908 (int) : min=-36000 max=36000 step=3600 default=0 value=0
tilt_absolute 0x009a0909 (int) : min=-36000 max=36000 step=3600 default=0 value=0
focus_absolute 0x009a090a (int) : min=0 max=250 step=5 default=0 value=0 flags=inactive
focus_auto 0x009a090c (bool) : default=1 value=1
zoom_absolute 0x009a090d (int) : min=100 max=500 step=1 default=100 value=100
v4l2-ctl --list-devices
HD Pro Webcam C920 (usb-70090000.xusb-2.2):
/dev/video0
