#!/usr/bin/python
# Back story
# v4l2-cli by itself does not accept config file
# camset allows us to save setting to text file, but it requires GUI to load it, which is inconvinient
# What I've done
# So I've written script that allows us to load settings from the config file, created with camset earlier
# Code is based on Camset (https://github.com/azeam/camset/)
# Run like: `python cliread.py myconfig.txt` (using myconfig.txt saved by camset)
# Change card to fit your video device

import subprocess
import sys

card = '/dev/video2'

# This part loads settings from file and applies them
def load_settings_from_file(filename):
    try:              
        f = open(filename, "r")
        lines = f.readlines()
        for line in lines:
            splits = line.split("=")
            setting = splits[0]
            value = splits[1]
            #if (setting == "resolution_index"):
            #        set_active_resolution(int(value))
            #        continue
            subprocess.run(['v4l2-ctl', '-d', card, '-c', '{0}={1}'.format(setting, value)], check=False, universal_newlines=True)
        f.close()
        print("Settings file {0} successfully loaded".format(filename))
    except Exception as e:
        print("Unable to load file {0} - {1}".format(filename, e))
        return
            
            
load_settings_from_file(sys.argv[1])

# This part applies 1280x720 resolution and MJPG format
# For list of your supported formats please run `v4l2-ctl -V`

subprocess.run(['v4l2-ctl -d ', card, ' -v width=1280,height=720,pixelformat=MJPG'], shell=True)

# Config sample (myconfig.txt file contents (remove #s if you want to use it)
#brightness=128
#contrast=128
#saturation=111
#white_balance_temperature_auto=0
#gain=50
#power_line_frequency=0
#white_balance_temperature=3500
#sharpness=140
#backlight_compensation=0
#exposure_auto=1
#exposure_absolute=300
#exposure_auto_priority=0
#pan_absolute=0
#tilt_absolute=0
#focus_absolute=0
#focus_auto=0
#zoom_absolute=100
#resolution_index=33