Stable: Define Monitors
From:     https://zoneminder.readthedocs.io/en/stable/userguide/definemonitor.html 



 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.

You can access the monitor window by clicking on the “Add New Monitor”
button, or by clicking on the “Source” column of a predefined monitor.
	 
	../_images/definemonitor-monitor.png

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. Here is an example
of the presets window:
	 
	../_images/definemonitor-preset.png

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 options 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.

 Server
Multi-Server implementation allows the ability to define multiple ZoneMinder 
servers sharing a single database. When servers are configured this setting 
allows you nominate the server for each monitor.

 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 Source tab.

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

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 to 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! To unlink a 
monitor you can ctrl-click.

 Maximum FPS
Warning
Unless you know what you are doing, please leave this field empty,
especially if you are configuring a network camera. More often than not,
putting a value here adversely affects recording.


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.

This feature is limited and will only work under the following conditions:

Using this field for video streams from IP cameras will cause undesirable 
results when the value is equal to or less than the frame rate from the camera.
Note that placing a value higher than the camera’s frame rate is allowed and can
help prevent cpu spikes when communication from the camera is lost.

 Alarm Maximum FPS
Warning
Unless you know what you are doing, please leave this field empty, especially 
if you are configuring a network camera. More often than not, putting a value 
here adversely affects recording.

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.

IMPORTANT: 
This field is subject to the same limitations as the Maximum FPS field. Ignoring
these limitations will produce undesriable results.

 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
 
FFmpeg
This is the recommended source type for most modern ip cameras.

Source Path
Use this field to enter the full URL of the stream or file your camera supports.
This is usually an RTSP url. There are several methods to learn this: 
 Source Colours
Specify the amount of colours in the captured image. 32 bit is the preferred 
choice here. 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
Make sure you enter here the same values as they are in the remote camera’s
internal setting.

 Keep aspect ratio
As per local devices.

 Orientation
As per local devices.




LibVLC
The fields for the LibVLC source type are configured the same way as the
ffmpeg source type. We recommend only using this source type if issues are
experienced with the ffmpeg source type.




cURL




Local

 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. Look in 
Supported Hardware section, how to see if your capture card or USB webcam is 
supported or not, and what extra settings you may have to do, to make it work.

 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 32 bit colour first, then 24 bit colour, then grey. If none of 
these work very well, and your camera is local, then YUV420P or one of the 
others probably will. There is a slight performance penalty when using palettes 
other than 32, 24, or grey palettes as an internal conversion is involved. 
Recent versions of ZoneMinder support 32bit colour. This capture palette 
provides a performance boost when used on all modern Intel-based processors.

 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 384x288 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.

 Keep aspect ratio
When typing in the dimensions of monitors you can click this checkbox to ensure
that the width stays in the correct ratio to the height, or vice versa. It 
allows height to be calculated automatically from width (or vice versa) 
according to preset aspect ratio. This is preset to 4:3 but can be amended 
globally via the Options->Config->ZM_DEFAULT_ASPECT_RATIO setting.  Aside from 
4:3 which is the usual for network and analog cameras another common setting is
11:9 for CIF (352x288) based sources.

 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.




Remote
 Remote Protocol Choices
are currently HTTP and RTSP. Before RTSP became the industry standard, many ip 
cameras streamed directly from their web portal. If you have an ip camera that
does not speak RTSP then choose HTTP here. If you camera does speak RTSP then
you should change your source type to ffmpeg instead of selecting RTSP here. The
Remote -> RTSP method is no longer being maintained and may go away at some 
point in the future.

 Remote Method
When HTTP is the Remote Protocol, your choices are Simple and Regexp.  Most 
should choose Simple. When RTSP is the Remote Protocol, your choices are 
RTP/Unicast, RTP/Multicast, RTP/RTSP, RTP,RTSP,HTTP. Try each of these to 
determine which works with your camera. Most cameras will use either RTP/Unicast
(UDP) or RTP/RTSP (TCP).

 
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.jpg
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 :@.com. This will usually be 32 or 24 bit colour even if the image 
looks black and white. Look in Supported Hardware > Network Cameras section,
how to obtain these strings that may apply to your camera.

 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
Make sure you enter here the same values as they are in the remote camera’s 
internal setting.

 Keep aspect ratio
As per local devices.

 Orientation
As per local devices.

For an example to setup a MPEG-4 camera see: How_to_Setup_an_Axis211A_with_MPEG-4_streaming




File


File Pat 
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 32 bit colour.
 
Capture Width/Height
As per local devices.
 
Keep aspect ratio
As per local devices.
 
Orientation
As per local devices.




WebSite

This Source Type allows one to configure an arbitrary website as a non-recordable,
 fully interactive, monitor in ZoneMinder. Note that sites with self-signed 
certificates will not display until the end user first manually navigates to the
site and accpets the unsigned certificate. Also note that some sites will set an
X-Frame option in the header, which discourages their site from being displayed
within a frame. ZoneMinder will detect this condition and present a warning in 
the log. When this occurs, the end user can choose to install a browser plugin 
or extension to workaround this issue.

 Website URL
Enter the full http or https url to the desired website.

 Width (pixels)
Chose a desired width in pixels that gives an acceptable appearance.  This may 
take some expirimentation.

 Height (pixels)
Chose a desired height in pixels that gives an acceptable appearance.  This may
take some expirimentation.

 Web Site Refresh
If the website in question has static content, optionally enter a time period 
in seconds for ZoneMinder to refresh the content.




Storage Tab
The storage section allows for each monitor to configure if and how video
and audio are recorded.

Save JPEGs
Records video in individual JPEG frames. Storing JPEG frames requires more 
storage space than h264 but it allows one to view an event anytime while it is 
being recorded.


Video Writer
Records video in real video format. It provides much better compression results
than saving JPEGs, thus longer video history can be stored. 
Recording Audio
Check the box labeled “Whether to store the audio stream when saving an event.”
in order to save audio (if available) when events are recorded.




Timestamp Tab

Timestamp Label Format
This relates to the timestamp that is applied to each frame. It is a ‘strftime’
style string with a few extra tokens. You can add %f to add the decimal 
hundredths of a second to the frame timestamp, so %H:%M:%S.%f will output time
like 10:45:37.45. You can also use %N for the name of the monitor and %Qwhich 
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.

 Stream Replay Image Buffer
The number of frames buffered to allow pausing and rewinding of the stream when
live viewing a monitor. A value of 0 disables the feature.  Frames are buffered
to ZM_PATH_SWAP. If this path points to a physical drive, a lot of IO will be
caused during live view / montage. If you experience high system load in those
situations, either disable the feature or use a RAM drive for ZM_PATH_SWAP.

 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 indicate 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 timeouthowever 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,


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-’, 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.

 Embed EXIF data into image:
Embeds EXIF data into each jpeg frame

Todo
what about mp4s?