Main Documentation

Please Note: The documentation for ZoneMinder is currently in the process of being migrated to this Wiki. The documents present in the distribution and available from the Documentation page on the main site should be used until such time as this notice is removed.

Introduction

Welcome to ZoneMinder, the all-in-one Linux GPL'd security camera solution.

A while back my garage was burgled and all my power tools were stolen! I realised shortly after that if I'd just had a camera overlooking the door then at least I'd have know exactly when and who did the dirty deed. And so ZoneMinder was born. It's still relatively new but hopefully it has developed to be something that can be genuinely useful and prevent similar incidents or even perhaps bring some perpetrators to justice.

ZoneMinder is designed around a series of independent components that only function when necessary limiting any wasted resource and maximising the efficiency of your machine. A fairly ancient Pentium II PC should be able to track one camera per device at up to 25 frames per second with this dropping by half approximately for each additional camera on the same device. Additional cameras on other devices do not interact so can maintain this frame rate. Even monitoring several cameras still will not overload the CPU as frame processing is designed to synchronise with capture and not stall it.

As well as being fast ZoneMinder is designed to be friendly and even more than that, actually useful. As well as the fast video interface core it also comes with a user friendly and comprehensive PHP based web interface allowing you to control and monitor your cameras from home or even at work or on the road. It supports variable web capabilities based on available bandwidth. The web interface also allows you to view events that your cameras have captured and archive them or review them time and again, or delete the ones you no longer wish to keep. The web pages directly interact with the core daemons ensuring full co-operation at all times. ZoneMinder can even be installed as a system service ensuring it is right there if your computer has to reboot for any reason.

The core of ZoneMinder is the capture and analysis of images and there is a highly configurable set of parameters that allow you to ensure that you can eliminate false positives whilst ensuring that anything you don't want to miss will be captured and saved. ZoneMinder allows you to define a set of 'zones' for each camera of varying sensitivity and functionality. This allows you to eliminate regions that you don't wish to track or define areas that will alarm if various thresholds are exceeded in conjunction with other zones.

ZoneMinder is fresh off the keyboard and so comes with no warranty whatsoever, please try it, send your feedback and if you get anything useful out of it let me know.

ZoneMinder is free but if you do get ZoneMinder up and running and find it useful then please feel free to visit http://www.zoneminder.com/donate.html where any donations will be appreciated and will help to fund future improvements to ZoneMinder. This would be especially relevant if you use ZoneMinder as part of your business, or to protect your property.

Requirements

ZoneMinder needs a couple of things to work. Ordinarily the ‘configure’ script will check for the presence of required (and optional) components but it is useful to be prepared beforehand.

Firstly, it uses MySQL so you'll need that. In order to compile you need to make sure you have a development installation and not just a runtime; this is because it needs to use the MySQL header files. If you are running an RPM based distribution then it’s probably worth installing all the pure mysql rpm files to be sure you have the right ones.

Next it does things with JPEGs so you'll need at least libjpeg.a which I think come as standard nowadays with most distributions. Users have reported varying degrees of success with other jpeg libraries such as jpeg-mmx but these are not officially supported. If you plan to use network cameras then the Perl Compatible Regular Expression library (libpcre.a) can prove useful but is not always essential. ZoneMinder also uses the netpbm utilities in a very limited way to generate thumbnails under certain circumstances though this can be modified.

ZoneMinder can generate MPEG videos if necessary, for this you'll need either ffmpeg (recommended) or the Berkeley MPEG encoder (mpeg_encode). If you don't have either, don't worry, as the options will be hidden and you'll not really miss too much. Some of the authentication uses openssl MD5 functions, if you get a grumble about these during configuration all it will mean is that authentication won’t be used for streaming. The web interface uses PHP and so you need that in your apache or other web server as well, make sure MySQL support is available either statically or as a module. There are also various perl modules that you may need that vary depending on which options you choose on installation, for more details see later in this document.

Finally, there is quite a bit of image streaming in the package. So if you don't have FireFox or another browser that supports image streaming natively I recommend you get the excellent Cambozola java applet from http://www.charliemouse.com/code/cambozola/ which will let you view the image stream in Internet Explorer and others. Otherwise you're limited to just refreshing still images or mpeg based streams, if you have compatible plugins.

Hardware-wise, ZoneMinder has been used with various video and USB cameras with the V4L interface. It will also work with most Network or IP cameras. I don't have a lot of cameras myself so I've not had change to test it with a huge range personally however there is a list of devices that are definitely known to work on the web site. Please enter you camera on the Wiki list on zoneminder.com if your camera works and is not listed. You do need to have Video4Linux installed. In terms of computer hardware, there are no hard and fast requirements. You may get a system that works with one or two cameras going on an old P200 but you will be able to support more cameras, at a higher frame rate, with faster machines with more RAM. More guidance is available on the web forums.

Components

ZoneMinder is not a single monolithic application but is formed from several components. These components primarily include executable compiled binaries which do the main video processing work, perl scripts which usually perform helper and/or external interface tasks and php web scripts which are used for the web interface.

A brief description of each of the principle components follows.

zmc

This is the ZoneMinder Capture daemon. This binary's job is to sit on a video device and suck frames off it as fast as possible, this should run at more or less constant speed.

zma

This is the ZoneMinder Analysis daemon. This is the component that goes through the captured frames and checks them for motion which might generate an alarm or event. It generally keeps up with the Capture daemon but if very busy may skip some frames to prevent it falling behind.

zmf

This is the ZoneMinder Frame daemon. This is an optional daemon that can run in concert with the Analysis daemon and whose function it is to actually write captured frames to disk. This frees up the Analysis daemon to do more analysis (!) and so keep up with the Capture daemon better. If it isn’t running or dies then the Analysis daemon just writes them itself.

zms

This is the ZoneMinder Streaming server. The web interface connects with this to get real-time or historical streamed images. It runs only when a live monitor stream or event stream is actually being viewed and dies when the event finishes or the associate web page is closed. If you find you have several zms processes running when nothing is being viewed then it is likely you need a patch for apache (see the Troubleshooting section). A non-parsed header version of zms, called nph-zms, is also installed and may be used instead depending on your web server configuration.

zmu

This is the ZoneMinder Utility. It's basically a handy command line interface to several useful functions. It’s not really meant to be used by anyone except the web page (there's only limited 'help' in it so far) but can be if necessary, especially for debugging video problems.

zmfix

This is a small binary that exists only to ensure that the video device files can be read by the main capture daemons. It is often the case that these device files are set to be accessible by root only on boot. This binary runs setuid and ensures that they have appropriate permissions. This is not a daemon and runs only on system start and then exits.

As well as this there are the web PHP files in the web directory and some perl scripts in the scripts directory. These scripts all have some configuration at the top of the files which should be viewed and amended if necessary and are as follows.

zmpkg.pl

This is the ZoneMinder Package Control script. This is used by the web interface and service scripts to control the execution of the system as a whole.

zmdc.pl

This is the ZoneMinder Daemon Control script. This is used by the web interface and the zmpkg.pl script to control and maintain the execution of the capture and analysis daemons, amongst others. You should not need to run this script yourself.

zmfilter.pl

This script controls the execution of saved filters and will be started and stopped by the web interface based on whether there are filters that have been defined to be autonomous. This script is also responsible for the automatic uploading of events to a 3rd party server.

zmaudit.pl

This script is used to check the consistency of the event file system and database. It can delete orphaned events, i.e. ones that appear in one location and not the other as well as checking that all the various event related tables are in line. It can be run interactively or in batch mode either from the command line or a cron job or similar. In the zmconfig.pl there is an option to specify fast event deletes where the web interface only deletes the event entry from the database itself. If this is set then it is this script that tidies up the rest.

zmwatch.pl

This is a simple script purely designed to keep an eye on the capture daemons and restart them if they lockup. It has been known for sync problems in the video drivers to cause this so this script makes sure that nothing important gets missed.

zmupdate.pl

Currently this script is responsible for checking whether a new version of ZoneMinder is available and other miscellaneous actions related to upgrades and migrations. It is also intended to be a ‘one stop shop’ for any upgrades and will execute everything necessary to update your installation to a new version.

zmvideo.pl

This script is used from the web interface to generate video files in various formats in a common way. You can also use it from the command line in certain circumstances but this is not usually necessary.

zmx10.pl

This is an optional script that can be used to initiate and monitor X10 Home Automation style events and interface with an alarm system either by the generation of X10 signals on ZoneMinder events or by initiating ZoneMinder monitoring and capture on receipt of X10 signals from elsewhere, for instance the triggering of an X10 PIR. For example I have several cameras that don’t do motion detection until I arm my alarm system whereupon they switch to active mode when an X10 signal is generated by the alarm system and received by ZoneMinder.

zmtrigger.pl

This is an optional script that is a more generic solution to external triggering of alarms. It can handle external connections via either internet socket, unix socket or file/device interfaces. You can either use it ‘as is’ if you can interface with the existing format, or override connections and channels to customise it to your needs. The format of triggers used by zmtrigger.pl is as follows "<id>|<action>|<score>|<cause>|<text>|<showtext>" where

• 'id' is the id number or name of the ZM monitor
• 'action' is 'on', 'off', 'cancel' or ‘show’ where 'on' forces an alarm condition on, 'off' forces an alarm condition off and 'cancel' negates the previous 'on' or 'off'. The ‘show’ action merely updates some auxiliary text which can optionally be displayed in the images captured by the monitor. Ordinarily you would use 'on' and 'cancel', 'off' would tend to be used to suppress motion based events. Additionally 'on' and 'off' can take an additional time offset, e.g. on+20 which automatically 'cancel's the previous action after that number of seconds.
• 'score' is the score given to the alarm, usually to indicate it's importance. For 'on' triggers it should be non-zero, otherwise it should be zero.
• 'cause' is a 32 char max string indicating the reason for, or source of the alarm e.g. 'Relay 1 open'. This is saved in the ‘Cause’ field of the event. Ignored for 'off' or 'cancel' messages
• 'text' is a 256 char max additional info field, which is saved in the ‘Description’ field of an event. Ignored for 'off' or 'cancel' messages.
• 'showtext' is up to 32 characters of text that can be displayed in the timestamp that is added to images. The ‘show’ action is designed to update this text without affecting alarms but the text is updated, if present, for any of the actions. This is designed to allow external input to appear on the images captured, for instance temperature or personnel identity etc.

Note that multiple messages can be sent at once and should be LF or CRLF delimited. This script is not necessarily intended to be a solution in itself, but is intended to be used as ‘glue’ to help ZoneMinder interface with other systems. It will almost certainly require some customisation before you can make any use of it. If all you want to do is generate alarms from external sources then using the ZoneMinder::SharedMem perl module is likely to be easier.

zmcontrol-*.pl

These are a set of example scripts which can be used to control Pan/Tilt/Zoom class cameras. Each script converts a set of standard parameters used for camera control into the actual protocol commands sent to the camera. If you are using a camera control protocol that is not in the shipped list then you will have to create a similar script though it can be created entirely separately from ZoneMinder and does not need to named as these scripts are. Although the scripts are used to action commands originated from the web interface they can also be used directly or from other programs or scripts, for instance to implement periodic scanning to different presets.

zmtrack.pl

This script is used to manage the experimental motion tracking feature. It is responsible for detecting that an alarm is taking place and moving the camera to point to the alarmed location, and then subsequently returning it to a defined standby location. As well as moving the camera it also controls when motion detection is suspended and restored so that the action of the camera tracking does not trigger endless further alarms which are not justified.

zm

This is the (optional) ZoneMinder init script, see below for details.

Finally, there are also a number of ZoneMinder perl modules included. These are used by the scripts above, but can also be used by your own or 3rd party scripts. Full documentation for most modules is available in ‘pod’ form via ‘perldoc’ but the general purpose of each module is as follows.

ZoneMinder.pm

This is a general ZoneMinder container module. It includes the Base.pm, Config.pm Debug.pm, Database.pm, and SharedMem.pm modules described below. It also exports all of their symbols by default. If you use the other modules directly you have request which symbol tags to import.

ZoneMinder/Base.pm

This is the base ZoneMinder perl module. It contains only simple data such as version information. It is included by all other ZoneMinder perl modules

ZoneMinder/Config.pm

This module imports the ZoneMinder configuration from the database.

ZoneMinder/Debug. pm

This module contains the defined Debug and Error functions etc, that are used by scripts to produce diagnostic information in a standard format.

ZoneMinder/Database.pm

This module contains database access definitions and functions. Currently not a lot is in this module but it is included as a placeholder for future development.

ZoneMinder/SharedMem.pm

This module contains standard shared memory access functions. These can be used to access the current state of monitors etc as well as issuing commands to the monitors to switch things on and off. This module effectively provides a ZoneMinder API.

ZoneMinder/ConfigAdmin.pm

This module is a specialised module that contains the definition, and other information, about the various configuration options. It is not intended for use by 3rd parties.

ZoneMinder/Trigger/*.pm

These modules contain definitions of trigger channels and connections used by the zmtrigger.pl script. Although they can be used ‘as is’, they are really intended as examples that can be customised or specialised for different interfaces. Contributed modules for new channels or connections will be welcomed and included in future versions of ZoneMinder.

Building

To build ZoneMinder the first thing you need to do is run the included configure script to define some initial configuration. If you are happy with the default settings for the database host (‘localhost’), name (‘zm’), user (‘zmuser’) and password (‘zmpass’) then you can just type

./configure --with-webdir=<your web directory> --with-cgidir=<your cgi directory>

where --with-webdir is the directory to which you want to install the PHP files, and --with-cgidir is the directory to which you want to install CGI files. These directories could be /var/www/html/zm and /var/www/cgi-bin for example.

If you want to override any of the default database values then you can append them to the configure command, for example to use a database password of ‘zmnewpass’ do

./configure --with-webdir=<your web directory> --with-cgidir=<your cgi directory> ZM_DB_PASS=zmnewpass

and so on. The values you can use are ZM_DB_HOST, ZM_DB_NAME, ZM_DB_USER and ZM_DB_PASS. Other than the database name, which is substituted into the database creation script, these values can easily be changed after this step.

If the script cannot find your MySQL installation, for instance if it is installed in an unusual location, then --with-mysql identifies the root directory where you have installed it, usually /usr.

If you want to use real MPEG based streaming you will need to have built and installed the ffmpeg tools. You can then also use --with-ffmpeg=<path to ffmpeg root> to help configure find it if it’s not installed in a default location. Note, you have to make sure you have installed the ffmpeg headers and libraries (make installlib) as well as the binaries (make install), or a development package with them in.

If you have built ffmpeg with any additional options which require extra libraries in the link stage then you can use --with-extralibs to pass these libraries to the configure script, to prevent unresolved dependencies. Otherwise ignore this option.

If you are on a 64 bit system you may find that the --with-libarch option helps you correctly define your library paths.

There are also two further parameters you can add if your web user and group are not both 'apache'. These are --with-webuser and --with-webgroup.

This is also when you have the opportunity to pass any additional flags to the compiler to modify how the application is built. To do this append CFLAGS=”<options>” and CXXFLAGS=”<options>” to pass in compiler flags for ‘c’ and ‘c++’ compilation respectively. For instance the default compiler flags are usually –O2 and –g to create binaries with moderate optimisation and debugging symbols. If you wanted to optimise further, including processor specific tweaks but still keep debugging symbols then could use CFLAGS="-g -O3 -march=pentium4" and CXXFLAGS="-g -O3 -march=pentium4" for instance. Consult the gcc/g++ documentation for help on these and other options. Also be aware that even if you optimise your ZoneMinder build, any libraries that get linked in will only perform as well as the options used when they were built allows. Thus to get full benefit you would usually need to rebuild libjpeg.a and/or other libraries with similar options.

Type

./configure –help

for details on these, and other, options.

Now you can just type make to do the build. The first time you run this you may get a warning about a Makefile being rebuilt in the scripts directory, and make will terminate. This is normal and you can just rerun make to complete the build.

Installation

Installation from Source

For a new installation the next thing you will need to do is create your database and database users. So type the commands as follows,

mysql mysql < db/zm_create.sql

mysql mysql

grant select,insert,update,delete on <database name>.* to '<database user>'@localhost identified by '<database password>';

quit

mysqladmin reload

You may need to supply a username and password to the mysql commands in the first place to give yourself sufficient privileges to perform the required commands. If you want to host your database on a different machine than that which ZoneMinder is running on then you will need to perform this step on the remote machine and reference the ZoneMinder machine instead of localhost. If you are running remote databases you probably already know all this, if you are not then don’t worry about it!

At this stage typing

make install

will install everything to the desired locations, you may need to su to root first though to give yourself adequate permissions. The installation routine will copy the binaries and scripts to your chosen install location, usually /usr/local/bin and then move zms (and nph-zms) to your cgi-bin area. It will then copy the web files to your chosen directory and ensure they have the right permissions, and install the ZoneMinder perl modules in the standard perl locations. It will also install a copy of the zm.conf file (generated by configure) to your system configuration area (e.g. /usr/local/etc). Finally it tries to link zm.php to index.php but will not overwrite an existing file if it already exists.

The 'zm' script does not get installed automatically as it is not necessary for the operation of the ZoneMinder setup per se and is not necessarily likely to work correctly for distributions other than those from the RedHat or Fedora families. However if you want to ensure that ZoneMinder is started on reboot etc copy it to your init.d directory, usually something like /etc/rc.d/init.d or /etc/inid.d and then add it by doing

chkconfig --add zm

or similar command for your distribution. ZoneMinder will then start up when your machine reboots and can be controlled (by the root user) by doing 'service zm start' or 'service zm stop' etc. You may need to use the ‘—levels’ parameter to chkconfig to ensure that ZoneMinder is started when you need it to.

If you do this you should find that you have files named S99zm in some of the /etc/rcX.d directories and K99zm in some of the others. The S99zm files are used for starting up ZoneMinder on system boot and the K99zm ones are used to close it on system shutdown. The 99 part is a priority, which may run from 0 to 99 and indicates where in the startup and shutdown sequences that ZoneMinder should start or stop. So S99zm means that ZoneMinder should be one of the last things to startup, which is good as it needs things like the database to be running first.

By the same token, the K00zm scripts indicate that ZoneMinder should be one of the first things to shut down. This prevents any nasty messages on your console about the database having gone away first and also will give ZoneMinder chance to shutdown in a controlled manner without introducing any corruption into the database or filesystem.

As mentioned above, this script is for Redhat, and related, distributions only. I would be grateful for any similar scripts for other distributions so if you know of one, or create one, then please send it to me.

If you are running a distribution which doesn’t support the zm script, or if you just prefer more direct control, you can now start ZoneMinder by typing

zmpkg.pl start

which, after a few seconds, should return without error. You can subsequently stop and restart everything by changing the ‘start’ parameter to ‘stop’ or ‘restart’.

Now fire up your web browser, point it at your zm.php and off you go.

Note, if you ever need to uninstall ZoneMinder you can do this by simply typing

make uninstall

though as with installation you may need to change user to have sufficient privileges. This will remove all installed files, however you will need to manually remove any databases you have created.

Installation from RPM

Installing from the RPM is distribution specific so make sure you download the correct RPM for the distribution that you are using.

All documents including this README are installed to the systems default document folder.

Fedora Core: /usr/share/doc/zm-{version number}

Mandrake:

The packaged version of Zone Minder installs all binarys to /usr/lib/zm including the web pages. So don’t worry when you do not see any files installed to the root directory for your web server. The web pages for Apache are aliased by zm.conf in the apache/conf.d directory which vary depending on your distribution:

Fedora Core: /etc/httpd/conf.d/zm.conf

Mandrake:

The Configuration file for setting up the database is located at /etc/zm.conf and will need to be edited to add the user and password that you want Zone Minder to use. After you have installed the Zone Minder package this will be the first thing you want to do. So use your favourite editor and add in the user name and password you want Zone Minder to use. You can also change the database name if you would like.

vi /etc/zm.conf

Start the mysqld service so you can build the database

service mysqld start

Then run zminit to create the database

/usr/lib/zm/bin/zminit

The user and password that zminit asks for are for the database only. For the user enter root and leave the password blank (unless of course you changed the password). You should see some information showing that it has created the database and no errors.

Set the run levels for the services that Zone Minder requires. I like to set the run levels to 3 and 5 with the following command:

chkconfig –levels 35 mysqld on

chkconfig –levels 35 httpd on

Now start the web server and Zone Minder:

service httpd start

service zm start

You should now be able to access the Zone Minder console through the web browser http://localhost/zm

Log files will be located in /var/log/zm

Events are located at /var/lib/zm

Upgrading

Upgrading from Source

If you are upgrading from a previous version of ZoneMinder you should follow the Building instructions above. Before proceeding, ensure that any previous version of ZoneMinder has been stopped, then type

make install

to install the binaries, scripts, modules, web and configuration files.

The next step in an upgrade is to run the zmupgrade.pl script to make any changes to the database or file system required by the new version. Ordinarily you can run this from your ZoneMinder build directory by doing

zmupdate.pl –version=<from version> [--user=<database user> --pass=<database password>]

where ‘from version’ relates to the version of ZM you are upgrading from, 1.21.1 for example, and not the version you are upgrading to. All updates from that version onwards will be applied; however zmupdate.pl will only work with upgrades from 1.19.0 onwards. The ‘user’ and ‘pass’ options allow you to specify a database user and password with sufficient privilege to ‘alter’ the structure of the database. This is not necessarily the database user you use for ZoneMinder.

The update script will offer you the chance to make a database backup before making any changes. You can use this to restore your database if the upgrade fails or if you simply wish to roll back in the future. Be aware that if you have a lot of entries in your database and/or limited disk space doing a backup may not be feasible or even work. Also the backup only applies to the database and will not save any images or other event detail saved on disk. If successful the backup will be saved in the current directory and will be named <database name>-<from version>.dump. Any previous backups of the same name will be overwritten without warning. The backup file is in the form of a simple sql script and can be used to restore the database simply by typing

mysql < zm-1.21.4.dump

for example.

After having done any backup, the database upgrade will be applied. Check that this is successful before continuing.

Once the upgrade process is complete, you can then restart ZoneMinder using the zmpkg.pl script or using the service control commands for your distribution. You should check /var/log/messages and the other ZoneMinder logs for the first few minutes to ensure that everything comes back up successfully.

Tutorial

What you see now (and subsequently) is the initial view that appears when running in non-authenticated mode. Authentication is an option that lets you specify whether anyone that goes to the ZoneMinder web pages must log themselves in, in order to be given permissions to perform certain tasks. Running in authenticated mode is recommended if your system is open to the internet at all. During installation a fully privileged user ‘admin’ has been created with a password also of ‘admin’. If you are using authentication you should change this password as soon as possible.

Once you’ve logged in, or if you are running in un-authenticated mode, you will now see the ZoneMinder Console window. This will resize itself to avoid being too intrusive on your desktop. Along the top there are several informational entries like the time of the last update and the current server load. There will also be an indication of the system state which will probably say ‘stopped’ to begin with. This is a link that you can click on to control the ZoneMinder system as a whole.

Below that are various other links including one detailing the current user (in authenticated mode only) and one allowing you to configure your bandwidth. This last one enables you to optimise your settings depending on where you are, the actual values relating to this are defined in the options. If you are using a browser on the same machine or network then choose high, over a cable or DSL link maybe choose medium and over a dialup choose low. You can experiment to see which is best. This setting is retained on a per machine basis with a persistent cookie. Also on this line are a number of other links that will be covered below.

Please bear in mind that from here on the descriptions of the web pages are based on what you will see if you are running as a fully authenticated user. If you are running in un-authenticated mode or as a less privileged user then some elements may not be shown or will be disabled.

Defining Monitors

To use ZoneMinder properly you need to define at least one Monitor. Essentially, a monitor is associated with a camera and can continually check it for motion detection and such like. So, next click 'Add New Monitor' to bring up the dialog. You will see a bunch of things you have to fill in.

To help you get started on the video configuration the best thing is to use a tool like 'xawtv' (http://bytesex.org/xawtv/) to get a picture you're happy with, and to check your camera works. Please note that just because you can see a video stream in these tools does not necessarily guarantee that your camera will work with ZoneMinder. This is because most tools just ‘map’ the video image through onto screen memory transparently without intercepting it, whereas ZoneMinder needs to capture the image and, usually, inspect it. This is called frame grabbing and to check it you should use the facility in xawtv, or other tool, to capture either one or more still images or possibly a movie. If this works and the images or movie are not garbage then the chances are that ZoneMinder will work fine also.

Once you have validated your camera run 'zmu -d <device_path> -q -v' to get a dump of the settings (note, you will have to additionally supply a username and password to zmu if you are running in authenticated mode). You can then enter these values into the video related options of the monitor configuration panel. The 'device_path' referred to here is the path to your video device file, for instance /dev/video0 etc. If 'zmu' gives you an error related to permissions run 'zmfix -a' to make sure you can access all the video devices.

There are a small number of camera setups that ZoneMinder knows about and which can be accessed by clicking on the ‘Presets’ link. Selecting one of the presets will fill in the monitor configuration with appropriate values but you will still need to enter others and confirm the preset settings.

The options are divided into a set of tabs to make it easier to edit. You do not have to ‘save’ to change to different tab so you can make all the changes you require and then click ‘Save’ at the end. The individual option are explained in a little more detail below,

Monitor Tab

Name

The name for your monitor. This should be made up of alphanumeric characters (a-z,A-Z,0-9) and hyphen (-) and underscore(_) only. Whitespace is not allowed.

Source Type

This determines whether the camera is a local one attached to a physical video or USB port on your machine, a remote network camera or an image source that is represented by a file (for instance periodically downloaded from a alternate location). Choosing one or the other affects which set of options are shown in the next tab.

Function

This essentially defines what the monitor is doing. This can be one of the following;

• None – The monitor is currently disabled and no streams can be viewed or events generated.
• Monitor – The monitor will only stream feeds but no image analysis is done and so no alarms or events will be generated,
• Modect – or MOtion DEteCTtion. All captured images will be analysed and events generated where motion is detected.
• Record – In this case continuous events of a fixed length are generated regardless of motion which is analogous to a convention time-lapse video recorder. No motion detection takes place in this mode.
• Mocord – This is a hybrid of Modect and Record and results in both fixed length events being recorded and also any motion being highlighted within those events.
• Nodect – or No DEteCTtion. This is a special mode designed to be used with external triggers. In Nodect no motion detection takes place but events are recorded if external triggers require it.

Generally speaking it is best to choose ‘Monitor’ as an initial setting here..

Enabled

The enabled field indicates whether the monitor should be started in an active mode or in a more passive state. You will nearly always want to check this box, the only exceptions being when you want the camera to be enabled or disabled by external triggers or scripts. If not enabled then the monitor will not create any events in response ot motion or any other triggers.

Linked Monitors

This field allows you to select other monitors on your system that act as triggers for this monitor. So if you have a camera covering one aspect of your property you can force all cameras to record while that camera detects motion or other events. You can either directly enter a comma separated list of monitor ids or click on ‘Select’ to choose a selection. Be very careful not to create circular dependencies with this feature however you will have infinitely persisting alarms which is almost certainly not what you want!

Maximum FPS

On some occasions you may have one or more cameras capable of high capture rates but find that you generally do not require this performance at all times and would prefer to lighten the load on your server. This option permits you to limit the maximum capture rate to a specified value. This may allow you to have more cameras supported on your system by reducing the CPU load or to allocate video bandwidth unevenly between cameras sharing the same video device. This value is only a rough guide and the lower the value you set the less close the actual FPS may approach it especially on shared devices where it can be difficult to synchronise two or more different capture rates precisely. This option controls the maximum FPS in the circumstance where no alarm is occurring only.

Alarm Maximum FPS

If you have specified a Maximum FPS it may be that you don’t want this limitation to apply when your monitor is recording motion or other event. This setting allows you to override the Maximum FPS value if this circumstance occurs. As with the Maximum FPS setting leaving this blank implies no limit so if you have set a maximum fps in the previous option then when an alarm occurs this limit would be ignored and ZoneMinder would capture as fast as possible for the duration of the alarm, returning to the limited value after the alarm has concluded. Equally you could set this to the same, or higher (or even lower) value than Maximum FPS for more precise control over the capture rate in the event of an alarm.

Reference Image Blend %ge

Each analysed image in ZoneMinder is a composite of previous images and is formed by applying the current image as a certain percentage of the previous reference image. Thus, if we entered the value of 10 here, each image’s part in the reference image will diminish by a factor of 0.9 each time round. So a typical reference image will be 10% the previous image, 9% the one before that and then 8.1%, 7.2%, 6.5% and so on of the rest of the way. An image will effectively vanish around 25 images later than when it was added. This blend value is what is specified here and if higher will make slower progressing events less detectable as the reference image would change more quickly. Similarly events will be deemed to be over much sooner as the reference image adapts to the new images more quickly. In signal processing terms the higher this value the steeper the event attack and decay of the signal. It depends on your particular requirements what the appropriate value would be for you but start with 10 here and adjust it (usually down) later if necessary.

Triggers

This small section lets you select which triggers will apply if the run mode has been set to ‘triggered’ above. The most common trigger is X10 and this will appear here if you indicated that your system supported it during installation. Only X10 is supported as a shipped trigger with ZoneMinder at present but it is possible that other triggers will become available as necessary. You can also just use ‘cron’ jobs or other mechanisms to actually control the camera and keep them completely outside of the ZoneMinder settings. The zmtrigger.pl script is also available to implement custom external triggering.

Source Tab (local device)

Device Path/Channel

Enter the full path to the device file that your camera is attached to, e.g. /dev/video0. Some video devices, e.g. BTTV cards support multiple cameras on one device so in this case enter the channel number in the Channel box or leave it at zero if you're using a USB camera or one with just one channel.

Device Format

Enter the video format of the video stream. This is defined in various system files (e.g. /usr/include/linux/videodev.h) but the two most common are 0 for PAL and 1 for NTSC.

Capture Palette

Finally for the video part of the configuration enter the colour depth. ZoneMinder supports a handful of the most common palettes, so choose one here. If in doubt try grey first, and then 24 bit colour. If neither of these work very well then YUV420P or one of the others probably will. There is a slight performance penalty when using palettes other than grey or 24 bit colour as an internal conversion is involved. These other formats are intended to be supported natively in a future version but for now if you have the choice choose one of grey or 24 bit colour.

Capture Width/Height

The dimensions of the video stream your camera will supply. If your camera supports several just enter the one you'll want to use for this application, you can always change it later. However I would recommend starting with no larger than 320x240 or 352x288 and then perhaps increasing and seeing how performance is affected. This size should be adequate in most cases. Some cameras are quite choosy about the sizes you can use here so unusual sizes such as 197x333 should be avoided initially.

Orientation

If your camera is mounted upside down or at right angles you can use this field to specify a rotation that is applied to the image as it is captured. This incurs an additional processing overhead so if possible it is better to mount your camera the right way round if you can. If you choose one of the rotation options remember to switch the height and width fields so that they apply, e.g. if your camera captures at 352x288 and you choose ‘Rotate Right’ here then set the height to be 352 and width to be 288. You can also choose to ‘flip’ the image if your camera provides mirrored input.

Source Tab (remote device)

Remote Host/Port/Path

Use these fields to enter the full URL of the camera. Basically if your camera is at http://camserver.home.net:8192/cameras/camera1.jpg then these fields will be camserver.home.net, 8192 and /cameras/camera1.jopg respectively. Leave the port at 80 if there is no special port required. If you require authentication to access your camera then add this onto the host name in the form <username>:<password>@<hostname>.com. This will usually be 24 bit colour even if the image looks black and white.

Remote Image Colours

Specify the amount of colours in the captured image. Unlike with local cameras changing this has no controlling effect on the remote camera itself so ensure that your camera is actually capturing to this palette beforehand.

Capture Width/Height

As per local devices.

Orientation

As per local devices.

Source Tab (file device)

File Path

Enter the full path to the file to be used as the image source.

File Colours

Specify the amount of colours in the image. Usually 24 bit colour.

Capture Width/Height

As per local devices.

Orientation

As per local devices.

Timestamp Tab

Timestamp Label Format

This relates to the timestamp that is applied to each frame. It is a ‘strftime’ style string. It is actually passed through strftime and then through printf to add the monitor name so a format of '%%s - %y/%m/%d %H:%M:%S' (note the double % at the beginning) would be recommended though you can modify it if necessary. If you don’t want a timestamp or have a camera that puts one on itself then leave this field blank. If you add a second %%s placeholder in the string this will be filled by any of the ‘show text’ detailed in the zmtriggers.pl section.

Timestamp Label X/Y

The X and Y values determine where to put the timestamp. A value of 0 for the X value will put it on the left side of the image and a Y value of 0 will place it at the top of the image. To place the timestamp at the bottom of the image use a value eight less than the image height.

Buffers Tab

Image Buffer Size

This option determines how many frames are held in the ring buffer at any one time. The ring buffer is the storage space where the last ‘n’ images are kept, ready to be resurrected on an alarm or just kept waiting to be analysed. It can be any value you like with a couple of provisos, (see next options). However it is stored in shared memory and making it too large especially for large images with a high colour depth can use a lot of memory. A value of no more than 50 is usually ok. If you find that your system will not let you use the value you want it is probably because your system has an arbitrary limit on the size of shared memory that may be used even though you may have plenty of free memory available. This limit is usually fairly easy to change, see the Troubleshooting section for details.

Warm-up Frames

This specifies how many frames the analysis daemon should process but not examine when it starts. This allows it to generate an accurate reference image from a series of images before looking too carefully for any changes. I use a value of 25 here, too high and it will take a long time to start, too low and you will get false alarms when the analysis daemon starts up.

Pre/Post Event Image Buffer

These options determine how many frames from before and after an event should be preserved with it. This allows you to view what happened immediately prior and subsequent to the event. A value of 10 for both of these will get you started but if you get a lot of short events and would prefer them to run together to form fewer longer ones then increase the Post Event buffer size. The pre-event buffer is a true buffer and should not really exceed half the ring buffer size. However the post-event buffer is just a count that is applied to captured frames and so can be managed more flexibly. You should also bear in mind the frame rate of the camera when choosing these values. For instance a network camera capturing at 1FPS will give you 10 seconds before and after each event if you chose 10 here. This may well be too much and pad out events more than necessary. However a fast video card may capture at 25FPS and you will want to ensure that this setting enables you to view a reasonable time frame pre and post event.

Alarm Frame Count

This option allows you to specify how many consecutive alarm frames must occur before an alarm event is generated. The usual, and default, value is 1 which implies that any alarm frame will cause or participate in an event. You can enter any value up to 16 here to eliminate bogus events caused perhaps by screen flickers or other transients. Values over 3 or 4 are unlikely to be useful however. Please note that if you have statistics recording enabled then currently statistics are not recorded for the first ‘Alarm Frame Count’-1 frames of an event. So if you set this value to 5 then the first 4 frames will be missing statistics whereas the more usual value of 1 will ensure that all alarm frames have statistics recorded.

Control Tab

Note: This tab and its options will only appear if you have selected the ZM_OPT_CONTROL option to indicated that your system contains cameras which are able to be controlled via Pan/Tilt/Zoom or other mechanisms. See the Camera Control section elsewhere in this document for further details on camera control protocols and methods.

Controllable

Check this box to indicate your camera can be controlled.

Control Type

Select the control type that is appropriate for your camera. ZoneMinder ships with a small number of predefined control protocols which will works with some cameras without modification but which may have to amended to function with others, Choose the edit link to create new control types or to edit the existing ones.

Control Device

This is the device that is used to control your camera. This will normally be a serial or similar port. If your camera is a network camera, you will generally not need to specify a control device.

Control Address

This is the address of your camera. Some control protocols require that each camera is identified by a particular, usually numeric id. If your camera uses addressing then enter the id of your camera here. If your camera is a network camera then you will usually need to enter the hostname or IP address of it here. This is ordinarily the same as that given for the camera itself.

Auto Stop Timeout

Some cameras only support a continuous mode of movement. For instance you tell the camera to pan right and then when it is aligned correctly you tell it to stop. In some cases it is difficult to time this precisely over a web interface so this option allows you to specify an automatic timeout where the command will be automatically stopped. So a value of 0.25 here can tell the script to stop moving a quarter of a second after starting. This allows a more precise method of fine control. If this value is left blank or at zero it will be ignored, if set then it will be used as the timeout however it will only be applied for the lower 25% of possible speed ranges. In other words if your camera has a pan speed range of 1 to 100 then selecting to move at 26 or over will be assumed to imply that you want a larger movement that you can control yourself and no timeout will be applied. Selecting motion at lower speeds will be interpreted as requiring finer control and the automatic timeout will be invoked.

Track Motion

This and the following four options are used with the experimental motion function. This will only work if your camera supports mapped movement modes where a point on an image can be mapped to a control command. This is generally most common on network cameras but can be replicated to some degree on other cameras that support relative movement modes. See the Camera Control section for more details. Check this box to enable motion tracking.

Track Delay

This is the number of seconds to suspend motion detection for following any movement that the camera may make to track motion.

Return Location

If you camera supports a ‘home’ position or presets you can choose which preset the camera should return to after tracking motion.

Return Delay

This is the delay, in seconds, once motion has stopped being detected, before the camera returns to any defined return location.

X10 Tab

Note: This tab and its options will only appear if you have indicated that your system supports the X10 home automation protocol during initial system configuration.

X10 Activation String

The contents of this field determine when a monitor starts and/or stops being active when running in ‘Triggered; mode and with X10 triggers. The format of this string is as follows,

• n : If you simply enter a number then the monitor will be activated when an X10 ON signal for that unit code is detected and will be deactivated when an OFF signal is detected.
• !n : This inverts the previous mode, e.g. !5 means that the monitor is activated when an OFF signal for unit code 5 is detected and deactivated by an ON.
• n+ : Entering a unit code followed by + means that the monitor is activated on receipt of a ON signal for that unit code but will ignore the OFF signal and as such will not be deactivated by this instruction. If you prepend a '!' as per the previous definition it similarly inverts the mode, i.e. the ON signal deactivates the monitor.
• n+<seconds> : As per the previous mode except that the monitor will deactivate itself after the given number of seconds.
• n- : Entering a unit code followed by - means that the monitor is deactivated on receipt of a OFF signal for that unit code but will ignore the ON signal and as such will not be activated by this instruction. If you prepend a '!' as per the previous definition it similarly inverts the mode, i.e. the OFF signal activates the monitor.
• n-<seconds> : As per the previous mode except that the monitor will activate itself after the given number of seconds.

You can also combine several of these expressions to by separating them with a comma to create multiple circumstances of activation. However for now leave this blank.

X10 Input Alarm String

This has the same format as the previous field but instead of activating the monitor with will cause a forced alarm to be generated and an event recorded if the monitor is Active. The same definition as above applies except that for activated read alarmed and for deactivated read unalarmed(!). Again leave this blank for now.

X10 Output Alarm String

This X10 string also has the same format as the two above options. However it works in a slightly different way. Instead of ZoneMinder reacting to X10 events this option controls how ZoneMinder emits X10 signals when the current monitor goes into or comes out of the alarm state. Thus just entering a number will cause the ON signal for that unit code to be sent when going into alarm state and the OFF signal when coming out of alarm state. Similarly 7+30 will send the unit code 7 ON signal when going into alarm state and the OFF signal 30 seconds later regardless of state. The combination of the X10 instruction allows ZoneMinder to react intelligently to, and also assume control of, other devices when necessary. However the indiscriminate use of the Input Alarm and Output Alarm signals can cause some horrendous race conditions such as a light going on in response to an alarm which then causes an alarm itself and so on. Thus some circumspection is required here. Leave this blank for now anyway.

Misc Tab

Event Prefix

By default events are named ‘Event-<event id>’, however you are free to rename them individually as you wish. This option lets you modify the event prefix, the ‘Event-‘ part, to be a value of your choice so that events are named differently as they are generated. This allows you to name events according to which monitor generated them.

Section Length

This specifies the length (in seconds) of any fixed length events produced when the monitor function is ‘Record’ or ‘Mocord’. Otherwise it is ignored. This should not be so long that events are difficult to navigate nor so short that too many events are generated. A length of between 300 and 900 seconds I recommended.

Frame Skip

This setting also applies only to the ‘Record’ or ‘Mocord’ functions and specifies how many frames should be skipped in the recorded events. The default setting of zero results in every captured frame being saved. Using a value of one would mean that one frame is skipped between each saved, two means that two frames are skipped between each saved frame etc. An alternate way of thinking is that one in every ‘Frame Skip + 1’ frames is saved. The point of this is to ensure that saved events do not take up too much space unnecessarily whilst still allowing the camera to capture at a fairly high frame rate. The alternate approach is to limit the capture frame rate which will obviously affect the rate at which frames are saved.

FPS Report Interval

How often the current performance in terms of Frames Per Second is output to the system log. Not used in any functional way so set it to maybe 1000 for now. If you watch /var/log/messages (normally) you will see this value being emitted at the frequency you specify both for video capture and processing.

Default Scale

If your monitor has been defined with a particularly large or small image size then you can choose a default scale here with which to view the monitor so it is easier or more visible from the web interface.

Web Colour

Some elements of ZoneMinder now use colours to identify monitors on certain views. You can select which colour is used for each monitor here. Any specification that is valid for HTML colours is valid here, e.g. ‘red’ or ‘#ff0000’. A small swatch next to the input box displays the colour you have chosen.

Finally, click 'Save' to add your monitor.

On the main console listing you will now see your monitor and some of its vital statistics. Most columns are also links and you get to other functions of ZoneMinder by choosing the appropriate one. Describing them left to right, they are as follows.

The first column is the Id, clicking on this gives you the opportunity to edit any of the settings you have just defined your monitor to have.

The next column is the Name column, clicking on this will give you the watch window where you can view a live feed from your camera along with recent events. This is described more fully below.

Following that are the Function and Source columns, which may be represented in various colours. Initially both will be showing red. This means that that monitor is not configured for any function and as a consequence has no zmc (capture) daemon running on it. If it were orange it would mean that a zmc daemon was running but no zma (analysis) daemon and green means both are running. In our case it is red because we defined the Monitor to have a Function of None so no daemons are required.

To get the daemons up and running you can either click on the source listed in the Source column and edit the monitor properties or click on the Function listed and change it to ’Monitor’, which will ensure that one or more appropriate daemons are started automatically. You need to ensure that you have started ZoneMinder before any of these settings actually has any effect.

Having a device status of red or orange does not necessarily constitute an error if you have deliberately disabled a monitor or have just put it into Passive mode.

If you have several cameras (and thus monitors) on a device the device status colour reflects all of them for the capture daemon. So if just one monitor is active then the daemon is active for both even if all the other monitors are switched off.

Once you have changed the function of your monitor, the main console window will be updated to reflect this change. If your device status does not go green then check your system and web server logs to see if it's something obvious.

You can now add further monitors if you have cameras set up to support them. Once you have one or more monitors you may notice the '<n> Monitors' title becomes a link. Clicking on this link will open up a window which allows you to assign your monitors to groups. These let you select certain monitors to view. For instance you may only wish to view outdoor monitors while indoors. You can also choose to view all of them. If you choose a group then your selection will be remembered via a cookie and will be used until you change it. You can call your groups anything you like, though ‘Mobile’ has a special meaning (see Mobile Devices below).

There may also be a ‘Cycle’ link which allows you to cycle through a shot from each of your monitors (in the selected group unless they are switched off) and get a streamed or still image from each in turn. Similarly if you see a link titled ‘Montage’ it will allow you view all your active enabled cameras (in the selected group) simultaneously. Be aware however that this can consume large amounts of bandwidth and CPU so should not be used continuously unless you have resource to burn.

Defining Zones

The next important thing to do with a new monitor is set up Zones for it to use. By default you'll already have one generated for you when you created your monitor but you might want to modify it or add others. Click on the Zones column for your monitor and you should see a small popup window appear which contains an image from your camera overlain with a stippled pattern representing your zone. In the default case this will cover the whole image. The colour of the zones appearing here is determined by what type they are. The default zone is Active and so will be red, Inclusive zones are orange, exclusive zones are purple, preclusive zones are blue and inactive zones are white.

Beneath the zones image will be a table containing a listing of your zones. Clicking on either the relevant bit of the image or on the Id or Name in the table will bring up another window where you can edit the particulars for your Zones. As you can see there are quite a few, so now is a good time to go through them.

The Zone view is split into two main areas, on the left is the options are area and on the right is the zone drawing area. A default or new zone will cover the whole drawing area and will overlay any other zones you already have on there. Unlike the previous zones image, the current zone is coloured green, other zones will be orange regardless of type. Your first task is to decide if you want the zone over the whole image or whether you can narrow down the detection area; the smaller the zone, the less processing time it takes to examine it. If you wish to the edit the dimensions of the zone you can either manually fill in the table containing the zone points under the image, or click on the zone corners once to select it (it should turn red), and then click on the desired location to relocate it. Moving your mouse over a point will highlight the corresponding entry in the points table and vice versa.

To add a new point, click on the ‘+’ next to the point entry in the point table. This will add another point directly between that and the next point. To delete a point, select it, and then click on the ‘-‘ link. The ‘X’ that appears in the same area just allows you to deselect that point and leave it in the same place. You can make zones almost any shape you like; except that zones may not self-intersect (i.e. edges crossing over each other) .

Once you have your zone the correct size and shape, you should now fill in the rest of the configuration. These options are as follows.

Name

This is just a label to identify the zone by. You can change this to be more representative if you like, though it isn't used much except for logging and debugging.

Type

This is one of the more important concepts in ZoneMinder and there are five to choose from.

• Active - This is the zone type you'll use most often, and which will be set for your default zone. This means that this zone will trigger an alarm on any events that occur within it that meet the selection criteria.
• Inclusive - This zone type can be used for any zones that you want to trigger an alarm only if at least one other Active zone has already triggered one. This might be for example to cover an area of the image like a plant or tree which moves a lot and which would trigger lots of alarms. Perhaps this is behind an area you'd like to monitor though, in this case you'd create an active zone covering the non-moving parts and an inclusive zone covering the tree perhaps with less sensitive detection settings also. If something triggered an alarm in the Active zone and also in the Inclusive zone they would both be registered and the resulting alarm would be that much bigger than if you had blanked it out altogether.
• Exclusive ­- The next zone Type is Exclusive. This means that alarms will only be triggered in this zone if no alarms have already been triggered in Active zones. This is the most specialised of the zone types and you may never use it but in its place it is very useful. For instance in the camera covering my garden I keep watch for a hedgehog that visits most nights and scoffs the food out of my cats bowls. By creating a sensitive Exclusive zone in that area I can ensure that a hedgehog alarm will only trigger if there is activity in that small area. If something much bigger occurs, like someone walking by it will trigger a regular alarm and not one from the Exclusive zone. Thus I can ensure I get alarms for big events and also special small events but not the noise in between.
• Preclusive - This zone type is relatively recent. It is called a Preclusive zone because if it is triggered it actually precludes an alarm being generated for that image frame. So motion or other changes that occur in a Preclusive zone will have the effect of ensuring that no alarm occurs at all. The application for this zone type is primarily as a shortcut for detecting general large-scale lighting or other changes. Generally this may be achieved by limiting the maximum number of alarm pixels or other measure in an Active zone. However in some cases that zone may cover an area where the area of variable illumination occurs in different places as the sun and/or shadows move and it thus may be difficult to come up with general values. Additionally, if the sun comes out rapidly then although the initial change may be ignored in this way as the reference image catches up an alarm may ultimately be triggered as the image becomes less different. Using one or more Preclusive zones offers a different approach. Preclusive zones are designed to be fairly small, even just a few pixels across, with quite low alarm thresholds. They should be situated in areas of the image that are less likely to have motion occur such as high on a wall or in a corner. Should a general illumination change occur they would be triggered at least as early as any Active zones and prevent any other zones from generating an alarm. Obviously careful placement is required to ensure that they do not cancel any genuine alarms or that they are not so close together that any motion just hops from one Preclusive zone to another. As always, the best way is to experiment a little and see what works for you.
• Inactive - This final zone type is the opposite of Active. In this zone type no alarms will ever be reported. You can create an Inactive zone to cover any areas in which nothing notable will ever happen or where you get constant false alarms that don't relate to what you are trying to monitor. An Inactive zone can overlay other zone types and will be processed first.

It was mentioned above that Inactive zones may be overlaid on other zones to blank out areas however as a general principle you should try and make zones abut each other as much as possible and not overlap. This helps avoid repeated duplicate processing of the same area. For instance an Inclusive zone overlaying an Active zone when all other settings are the same will always trigger when the Active zone does which somewhat defeats the object of the exercise. One exception to this is Preclusive zones. These may be situated within Active areas are they are processed first and if small may actually save processing time by preventing full analysis of the image.

Presets

This contains a predefined list of some common zone settings. Selecting one will fill in some of the other fields in the page and help you to pick appropriate values for your zones. Note that it may be that none of the presets will be appropriate for your purposes so it is worth going through the individual options below to ensure that each has a sensible value.

Units

This setting which details whether certain of the following settings are in Pixels or Percent, where ‘Percent’ refers to a percentage area of the zone itself. In general ‘Pixels’ is more precise whereas percentages are easier to use to start with or if you change image sizes frequently. If you change this setting all appropriate values below are redisplayed in the correct context. A good tip would be to initially enter the settings in Percent and then change to Pixels if you wish to be more precise. Be aware though that repeated flipping between the settings may cause rounding errors. Note, the sense of the percentage values refers to the area of the zone and not the image as a whole. This makes trying to work out necessary sizes rather easier.

Alarm Colour

The option after that allows you to specify what colour you'd like any alarms this zone generates to be highlighted on images. Pick anything you like that will show up against your normal image background. This option is irrelevant for Preclusive and Inactive zones and will be disabled. For Inactive zones all subsequent options are likewise disabled.

Alarm Check Method

This setting allows you to specify the nature of the alarm checking that will take place, and more specifically what tests are applied to determine whether a frame represents an alarm or not. The three options are ‘AlarmPixels’, ‘FilteredPixels’ and ‘Blobs’ and depending on which option is chosen some of the following other settings may become unavailable. The first of these indicates that only a count of individual alarmed pixels should be used to determine the state of a image, the second indicate that the pixels should be filtered to remove isolated pixels (see below) before being counted, and the third uses a more sophisticated analysis which is designed to aggregate alarmed pixels into continuous groups, or ‘blobs’. Blob analysis default, however this method takes slightly longer and so if you find that one of the other methods works just as well for you and you wish to maximise performance you can opt for that instead. Some of the more useful alarm related features such as highlighted analysis images are only available with the ‘Blob’ setting.

Min/Maximum Pixel Threshold

These setting are used to define limits for the difference in value between a pixel and its predecessor in the reference image. For greyscale images this is simple but for colour images the colours are averaged first, originally this used an RMS (root mean squared) algorithm but calculating square roots mugs performance and does not seem to improve detection. Using an average means that subtle colour changes without any brightness change may go undetected but this is not the normal circumstance. There is also the option to use a more sophisticated integer algorithm to calculate a Y (or brightness) value from the colours themselves.

Filter Width/Height

To improve detection of valid event ZoneMinder applies several other functions to the data to improve its ability to distinguish interesting signals from uninteresting noise. The first of these is a filter that removes any pixels that do not participate in a contiguous block of pixels above a certain size. :These options are always expressed in pixels and should be fairly small, and an odd number, three or five is a good value to choose initially. Application of this filter removes any tiny or discontinuous pixels that don't form part of a discrete block.

Zone Area

This field differs from the others in that it may not be written to. It is there purely as a useful reference, when working in pixel units, of the area of the zone.

Min/Maximum Alarmed Area

The following two settings define the minimum and maximum number of pixels that exceed this threshold that would cause an alarm. If the units are Percent this (and following options) refers to the percentage of the frame and not the zone, this is so these values can be related between zones. The minimum value must be matched or exceeded for an alarm to be generated whereas the maximum must not be exceeded or the alarm will be cancelled. This is to allow for sudden changes such as lights coming on etc, which you may wish to disregard. In general a value of zero for any of these settings causes that value to be ignored, so you can safely set a maximum to zero and it will not be used. The use of just a number of pixels is however a very brute force method of detection as many small events dispersed widely are not distinguished from a compact one.

Min/Maximum Filtered Area

These are two additional bounds that specify the limits of pixels that would cause an alarm after this filtering process. As the filtering process can only remove alarmed pixels it makes no sense for the Minimum and Maximum Filtered Area to be larger than the equivalent Alarmed Area and in general they should be smaller or the same.

Min/Maximum Blob Area

The next step in the analysis phase is the collation of any remaining alarmed areas into contiguous blobs. This process parses the image and forms any pixels that adjoin other alarmed pixels into one or more larger blobs. These blobs may be any shape and can be as large as the zone itself or as small as the filtered size. The Minimum and Maximum Blob Size settings allow you to define limits within which an alarm will be generated. Of these only the Minimum is likely to be very useful.

Min/Maximum Blobs

Finally the Minimum and Maximum Blobs settings specify the limits of the actual number of blobs detected. If an image change satisfies all these requirements it starts or continues an alarm event.

Viewing Monitors

As this point you should have one or more Monitors running with one or more Zones each. Returning to the main Console window you will see your monitors listed once more. The columns not explored so far are the Monitor name, and various event totals for certain periods of time. Clicking on any of the event totals will bring up a variation on the same window but click on the Monitor name for now. If it is not a link then this means that that monitor is not running so ensure that you have started ZoneMinder and that your Monitor function is not set to ‘None’. If the link works, clicking on it will pop another window up which should be scaled to contain a heading, an image from your monitor, a status and a list of recent events if any have been generated.

Depending on whether you are able to view a streamed image or not the image frame will either be this stream or a series of stills. You have the option to change from one to the other (if available) at the centre of the top heading. Also along the top are a handful of other links. These let you change the scale of the image stream, modify image settings (for local devices) or close the window. If you have cameras that can be controlled, a ‘Control’ link should also be present which is described below.

The image should be self-explanatory but if it looks like garbage it is possible that the video configuration is wrong so look in your system error log and check for or report anything unusual. The centre of the window will have a tiny frame that just contains a status; this will be 'Idle', 'Alarm' or 'Alert' depending on the function of the Monitor and what's going on in the field of view. Idle means nothing is happening, Alarm means there is an alarm in progress and Alert means that an alarm has happened and the monitor is ‘cooling down’, if another alarm is generated in this time it will just become part of the same event. These indicators are colour coded in green, red and amber.

By default if you have minimised this window or opened other windows in front it will pop up to the front if it goes to Alarm state. This behaviour can be turned off in ‘options’ if required. You can also specify a sound file in the configuration, which will be played when an alarm occurs to alert you to the fact if you are not in front of your computer. This should be a short sound of only a couple of seconds ideally. Note that as the status is refreshed every few seconds it is possible for this not to alert you to every event that takes place, so you shouldn't rely on it for this purpose if you expect very brief events. Alternatively you can decrease the refresh interval for this window in the configuration though having too frequent refreshing may impact on performance.

Below the status is a list of recent events that have occurred, by default this is a listing of just the last 10 but clicking on 'All' will give you a full list and 'Archive' will take you to the event archive for this monitor, more on this later. Clicking on any of the column headings will sort the events appropriately.

From here you can also delete events if you wish. The events themselves are listed with the event id, and event name (which you can change), the time that the event occurred, the length of the event including any preamble and postamble frames, the number of frames comprising the event with the number that actually contain an alarm in brackets and finally a score. This column lists the average score per alarm frame as well as the maximum score that any alarm frame had.

The score is an arbitrary value that essentially represents the percentage of pixels in the zone that are in blobs divided by the square root of the number of blobs and then divided by the size of the zone. This gives a nominal maximum of 100 for a zone and the totals for each zone are added together, Active zones scores are added unchanged, Inclusive zones are halved first and Exclusive zones are doubled. In reality values are likely to be much less than 100 but it does give a simple indication of how major the event was.