I have 2 FOSCAM HD IP camera and 1 UBNT airVision (old model) IP camera which are used for surveillance monitoring. Storage of images is done on the camera's itself, so I only needed something to view the live feeds of the camera's combined an a single screen. I had an old HDMI screen laying around and the Raspberry Pi 3 is yet the perfect (inexpesive fit) for this purpose.
= Getting started =
Install the standard debian Raspberry Pi and make sure to select console mode. We do need any GUI, since we will be using omxplayer to display the camera feeds. Also find out your RTSP streaming URLs.
= Display camera images =
I use the [http://cr.yp.to/daemontools.html daemontools] framework, since it provides me with logging, monitoring, restarting out-of-the-box. I also like the way his way of thinking, to avoid reinventing the wheel everytime you need to write an deamon.
file:/etc/motd:
{{{
WWW: http://rickvanderzwet.nl - webcampi @ rustdam
/etc/service/camera1 = Hooiberg (via 'Rustdam Stal') - Main View
/etc/service/camera2 = Receptie (via wired and proxied on rustdam2.gw) - Left bottom
/etc/service/camera3 = Stal (wireless connected to rustdam.wleiden.net - rdr at rustdam2.gw)
}}}
file:/etc/service/camera1/run:
{{{
#!/bin/sh
exec 2>&1
exec omxplayer --threshold 0 --win 0,0,1280,720 --live 'rtsp://USER:PASSWORD@IP:PORT/videoMain'
}}}
file:/etc/service/camera2/run:
{{{
#!/bin/sh
exec 2>&1
exec omxplayer --threshold 0 --win 739,720,1280,1024 --layer 10 --live 'rtsp://USER:PASSWORD@IP:PORT/videoMain'
}}}
file:/etc/service/camera3/run:
{{{
#!/bin/sh
exec 2>&1
exec omxplayer --threshold 0 --win 0,720,540,1024 --layer 10 --live 'rtsp://USER:PASSWORD@IP:PORT/videoMain'
}}}
= Monitoring of camera feeds =
file:/root/kill_stuck_omxplayer.sh:
{{{
#!/bin/sh
#
# Quick to deal with omxplayers which are in deadloop,
# detection based on low-CPU usage
#
for PID in `pgrep omxplayer.bin`; do
PCPU=`ps -p $PID -o pcpu=`
if echo $PCPU 2.0 | awk '{exit $1<$2?0:1}'; then
echo "Lets kill pid $PID"
kill -KILL $PID
fi
done
}}}
file:/etc/crontab:
{{{
* * * * * root /root/kill_stuck_omxplayer.sh | logger
}}}
= Rsyslog issues =
My log was flooding with messages like this:
{{{
Jun 5 10:08:31 raspberrypi rsyslogd-2007: action 'action 17' suspended, next retry is Mon Jun 5 10:10:01 2017 [try http://www.rsyslog.com/e/2007 ]
}}}
Looking at the [https://www.raspberrypi.org/forums/viewtopic.php?f=91&t=122601| RaspberryPi Forum] it was caused by messages not being read from file:/dev/xconsole To fix this edit file:/etc/rsyslog.conf and comment out the block sending the entries:
{{{
daemon.*;mail.*;\
news.err;\
*.=debug;*.=info;\
*.=notice;*.=warn |/dev/xconsole
}}}
= Remote monitoring of screen output =
For debugging I remotely need to be able to look at the screen to see what is displayed. This is done by using [https://github.com/AndrewFromMelbourne/raspi2png.git raspi2png] to grep the output of the display and present then using Apache.
== Compile and install raspi2png ==
$ mkdir src; cd src
$ git clone https://github.com/AndrewFromMelbourne/raspi2png.git
$ cd raspi2png
$ sudo make install
== Install webserver ==
$ sudo apt-get install apache2
$ sudo chown -R pi:pi /var/www/html
== Generate display content ==
file:/var/www/html:
{{{
}}}
== Include screen capture ==
file:/etc/crontab:
{{{
* * * * * pi /usr/bin/raspi2png -p /var/www/html/snapshot.png 2>&1 | logger -t raspi2png
}}}