I have automatic exposure set, but it reacts very slowly and sometimes not at all (but with cheese it works fine). I'm taking timelapse pictures with following command:
ffmpeg -f video4linux2 -s 1280x720 -i /dev/video0 -vf drawtext="fontfile=/usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf:text='%{localtime\:%T}':x=20:y=20:fontcolor=white" -vframes 1 $(date +%Y-%m-%d-%H-%M-%S).jpg
So, my question is, how to trigger the exposure adjustment like in what cheese does (but in terminal)?
$ v4l2-ctl -L
brightness 0x00980900 (int) : min=-64 max=64 step=1 default=0 value=0
contrast 0x00980901 (int) : min=0 max=50 step=1 default=0 value=0
saturation 0x00980902 (int) : min=0 max=100 step=1 default=55 value=55
hue 0x00980903 (int) : min=-100 max=100 step=1 default=0 value=0
white_balance_temperature_auto 0x0098090c (bool) : default=1 value=1
gamma 0x00980910 (int) : min=100 max=300 step=1 default=100 value=100
power_line_frequency 0x00980918 (menu) : min=0 max=2 default=2 value=1
0: Disabled
1: 50 Hz
2: 60 Hz
white_balance_temperature 0x0098091a (int) : min=2800 max=6500 step=10 default=4500 value=4500 flags=inactive
sharpness 0x0098091b (int) : min=0 max=10 step=1 default=2 value=2
backlight_compensation 0x0098091c (int) : min=0 max=4 step=1 default=1 value=1
exposure_auto 0x009a0901 (menu) : min=0 max=3 default=3 value=1
1: Manual Mode
3: Aperture Priority Mode
exposure_absolute 0x009a0902 (int) : min=5 max=10000 step=1 default=166 value=5
