AxisMotionDetection

I had this performance problem while monitoring and event recording for 8-10 IP cameras using the ZM.

ZM is too good a software to abandon just for performance issues. So I decided I should pay more attention to the motion detection feature of the cameras I have and relieve the ZM server from the task of detecting motion.

I've finally managed to use the on-camera motion detection feature of Axis Cams and here are my notes:

I've set my Axis camera as follows:

Error creating thumbnail: Unable to save thumbnail to destination

Error creating thumbnail: Unable to save thumbnail to destination

The text "1|on 5|5|cause|text|showtext" means that alarm will be triggered for the monitor which has ID=1, alarm will set recording on alarm will be cleared after 5 seconds. The score of the alarm is 5 ( any score >0 is OK) "text" and "showtext" are just explanatory notes.

The ZM specs tells us that the format of the message can include a "duration" as long as the message is sent as: "1|on+5|5|cause|text|showtext" bu the problem is the Axis camera cannot or will not save the "+" sign which appears in the message. A CGI parameter conversion problem I presume...

I've taken care of this "+" problem with a small modification in zmtrigger.pl source (see below).

Next, I specified the host IP address of the zm computer and its default zmtrigger port of 6802.

Error creating thumbnail: Unable to save thumbnail to destination

Error creating thumbnail: Unable to save thumbnail to destination

The second important setup is the "motion detection" setup on the Axis. I created a window which covers the area of interest; kept the object size as small as possible, pulled the history slider all the way back to zero and left the sensitivity slide somewhere past the %50 value.

Now to the ZM settings...

There is no special setting for the ZM except that I've assigned the "Nodect" function to my camera monitor.

Error creating thumbnail: Unable to save thumbnail to destination

Finally, I modified the zmtrigger.pl file so that the first few lines of the function handleMessage looks like this:

Code: sub handleMessage {

       my $connection = shift;
       my $message = shift;
       #
       #  CUA  - Axis camera send the message quoted with"
       #  CUA  - Also Axis camera cannot save the plus sign which
       #  CUA  - possibly exists in the 1|on+20|score|cause|text|showtext formatted msg

       $message=~ s/^\"//g;
       $message=~ s/\"$//g;
       $message=~ s/on /on\+/;

       #  CUA - end of modifications

       my ( $id, $action, $score, $cause, $text, $showtext ) = split( /\|/, $message );

a few other modifications I made in the zmtrigger.pl file are commenting out some unused modules and pushes:

Code: use ZoneMinder::Trigger::Channel::Inet;

1. CUA use ZoneMinder::Trigger::Channel::Unix;
2. CUA use ZoneMinder::Trigger::Channel::Serial;

use ZoneMinder::Trigger::Connection;

my @connections; push( @connections, ZoneMinder::Trigger::Connection->new( name=>"Chan1", channel=>ZoneMinder::Trigger::Channel::Inet->new( port=>6802 ), mode=>"rw" ) );

1. CUA push( @connections, ZoneMinder::Trigger::Connection->new( name=>"Chan2", channel=>ZoneMinder::Trigger::Channel::Unix->new( path=>'/tmp/test.sock' ), mode=>"rw" ) );
2. push( @connections, ZoneMinder::Trigger::Connection->new( name=>"Chan3", channel=>ZoneMinder::Trigger::Channel::File->new( path=>'/tmp/zmtrigger.out' ), mode=>"w" ) );
3. CUA push( @connections, ZoneMinder::Trigger::Connection->new( name=>"Chan4", channel=>ZoneMinder::Trigger::Channel::Serial->new( path=>'/dev/ttyS0' ), mode=>"rw" ) );

my modifs are marked with "# CUA"

These three regular expressions remove the quotes sent by Axis which envelope the message string and insert a plus sign if the "on" command is followed by a space). These 3 statements convert an incoming message of the form

Code: "1|on 25|5|cause|text|showtext"

to

Code: 1|on+25|5|cause|text|showtext

and of course, you shouln"t forget to restart zmtrigger.pl; or better still modify the zm startup script so that it starts zmtrigger.pl everytime zm is [re]started.

I added the line '/usr/bin/zmtrigger.pl &" in the start section of /etc/init.d/zoneminder and also added the line "pkill zmtrigger.pl" in the stop section.

Code:

start() {

       echo -n "Starting $prog: "
       $command start
       # CUA
       /usr/bin/zmtrigger.pl &

       RETVAL=$?
       [ $RETVAL = 0 ] && echo success
       [ $RETVAL != 0 ] && echo failure
       echo
       [ $RETVAL = 0 ] && touch /var/lock/zm
       return $RETVAL

} stop() {

       echo -n $"Stopping $prog: "
       #
       # Why is this status check being done?
       # as $command stop returns 1 if zoneminder
       # is stopped, which will result in
       # this returning 1, which will stuff
       # dpkg when it tries to stop zoneminder before
       # uninstalling . . .
       #
       # CUA
       pkill zmtrigger.pl

I just hope that this helps other people trying to implement the on-camera motion detection with ZM.

Again; many thanks to those people who developed ZM at the first place and to those who helped it to become a perfect opensource project.