text: Title: Logitech C920 Issues
  Body: Hey there!  Love Mycodo so far!  Working on a temp/humidity controlled relay setup for outlets shortly.  :)
  
  However, I've run into an issue with trying to optimize my Camera settings for a spare webcam I have on-site, the Logitech C920 webcam on a Raspberry Pi 4 using opencv and would greatly appreciate your help.
  
  There are several issues I'm seeing related to camera setup--
  
  Upon default add, the image is grayscale -- I'm working within the v412-ctl CLI command to tweak the saturation and contrast to get it to a decent color depth and focus, but upon increasing the aforementioned values to ~100-150 (out of max 255), I start running into the following error shown in debug mode followed by corrupted video stream:
  
  Corrupt JPEG data: 304 extraneous bytes before marker 0xd7
  Corrupt JPEG data: 408 extraneous bytes before marker 0xd2
  Corrupt JPEG data: 973 extraneous bytes before marker 0xd5
  Corrupt JPEG data: found marker 0xd6 instead of RST7
  Corrupt JPEG data: 208 extraneous bytes before marker 0xd6
  Corrupt JPEG data: premature end of data segment
  Corrupt JPEG data: 157 extraneous bytes before marker 0xd2
  Corrupt JPEG data: premature end of data segment
  Corrupt JPEG data: 644 extraneous bytes before marker 0xd4
  Corrupt JPEG data: 540 extraneous bytes before marker 0xd0
  Corrupt JPEG data: 1169 extraneous bytes before marker 0xd6
  Corrupt JPEG data: 1077 extraneous bytes before marker 0xd7
  Corrupt JPEG data: premature end of data segment
  Corrupt JPEG data: premature end of data segment
  Corrupt JPEG data: 1161 extraneous bytes before marker 0xd3
  Corrupt JPEG data: premature end of data segment
  Corrupt JPEG data: 193 extraneous bytes before marker 0xd2
  Corrupt JPEG data: premature end of data segment
  Corrupt JPEG data: 796 extraneous bytes before marker 0xd2
  Corrupt JPEG data: 106 extraneous bytes before marker 0xd3
  Corrupt JPEG data: premature end of data segment
  Corrupt JPEG data: 99 extraneous bytes before marker 0xd7
  
  This is equally weird as I've used this webcam successfully on Octoprint (raspi 3D Printing using the same tweaks) as a live print webcam.  Unfortunately, I don't know what the delta is between their webcam implementation and Mycodo's.
  
  I also noticed that increasing the values past ~150-160 causes the frontend to crash.
  
  Any thoughts on resolution of these issues?  Alternatively, are there any webcams that are recommended as 100% working?
  