FAQ

2013-05-16T12:27:21Z

Bs27975: /* Why can't I see streamed images when I can see stills in the Zone window etc? */

== ZoneMinder Frequently Asked Questions ==

This is the new FAQ page. I will be migrating the existing FAQs here as soon as possible. In the meantime the old FAQ page is available [http://www.zoneminder.com/faq.html here].

Feel free to contribute any FAQs that you think are missing.

===How can I stop ZoneMinder filling up my disk?===

Recent versions of ZoneMinder come with a filter you can use for this purpose already included. However '''by default it is not enabled for event deletion'''.

The filter is called ''PurgeWhenFull'' and to find it, choose one of the event counts from the console page, for instance events in the last hour, for one of your monitors.

This will bring up an event listing and a filter window.

In the filter window there is a drop down select box labeled 'Use Filter', that lets your select a saved filter. Select 'PurgeWhenFull' and it will load that filter.

Make any modifications you might want, such as the percentage full you want it to kick in, or how many events to delete at a time (it will repeat the filter as many times as needed to clear the space, but will only delete this many events each time to get there).

Then click on 'Save' which will bring up a new window. Make sure the 'Automatically delete' box is checked and press save to save your filter. This will then run in the background to keep your disk within those limits.

After you've done that, you changes will automatically be loaded into zmfilter within a few minutes.

Check the <tt>zmfilter.log</tt> file to make sure it is running as sometimes missing perl modules mean that it never runs but people don't always realize.

There are two methods for ZM to remove files when they are deleted that can be found in Options under the System tab ZM_OPT_FAST_DELETE and ZM_RUN_AUDIT.

ZM_OPT_FAST_DELETE:

Normally an event created as the result of an alarm consists of entries in one or more database tables plus the various files associated with it. When deleting events in the browser it can take a long time to remove all of this if your are trying to do a lot of events at once. It is recommended that you set this option which means that the browser client only deletes the key entries in the events table, which means the events will no longer appear in the listing, and leaves the zmaudit daemon to clear up the rest later.

ZM_RUN_AUDIT:

The zmaudit daemon exists to check that the saved information in the database and on the file system match and are consistent with each other. If an error occurs or if you are using 'fast deletes' it may be that database records are deleted but files remain. In this case, and similar, zmaudit will remove redundant information to synchronize the two data stores. This option controls whether zmaudit is run in the background and performs these checks and fixes continuously. This is recommended for most systems however if you have a very large number of events the process of scanning the database and file system may take a long time and impact performance. In this case you may prefer to not have zmaudit running unconditionally and schedule occasional checks at other, more convenient, times.

ZM_AUDIT_CHECK_INTERVAL:

The zmaudit daemon exists to check that the saved information in the database and on the files system match and are consistent with each other. If an error occurs or if you are using 'fast deletes' it may be that database records are deleted but files remain. In this case, and similar, zmaudit will remove redundant information to synchronize the two data stores. The default check interval of 900 seconds (15 minutes) is fine for most systems however if you have a very large number of events the process of scanning the database and file system may take a long time and impact performance. In this case you may prefer to make this interval much larger to reduce the impact on your system. This option determines how often these checks are performed.

===What does a 'Can't shmget: Invalid argument' error in my logs mean? and my cameras won't display video at higher resolutions.===

This error is discussed in the README in the following excerpt:-
''...this is caused by an attempt to allocate an amount of shared memory greater than your system can handle. The size it requests is based on the following formula, <tt>ring buffer size x image width x image height x 3 (for 24 bit images) + a bit of overhead</tt>.

So, for example:
<pre>384x288 capture resolution, that makes: 110 592 pixels
in 24 bit color that's x24 = 2 654 208 bits per frame
by 80 frames ring buffer x80 = 212 336 640 bits per camera
by 4 cameras x4 = 849 346 560 bits.
Plus 10% overhead = 934 281 216 bits
That's 116 785 152 bytes, and
= 114 048 kB, respectively 111.38 MB.
If my shared memory is set to 134 217 728, which is exactly 128MB,
that means I shouldn't have any problem.
(Note that 1 byte = 8 bits and 1kbyte = 1024bytes, 1MB = 1024 kB)</pre>

If for instance you were using 24bit 640x480 then this would come to about 92Mb if you are using the default buffer size of 100. If this is too large then you can either reduce the image or buffer sizes or increase the maximum amount of shared memory available. If you are using RedHat then you can get details on how to change these settings at http://www.redhat.com/docs/manuals/database/RHDB-2.1-Manual/admin_user/kernel-resources.html .

You should be able to use a similar procedure with other distributions to modify the shared memory pool without kernel recompilations though in some cases this may be necessary. Note, this error also sometimes occurs if you have an old shared memory segment lying around from a previous run that is too small. Use the ipcs and ipcrm system commands to check and remove it if necessary.'"

You can often find out how many 4KB shared memory pages are available by typing the following :-
<pre># cat /proc/sys/kernel/shmall
2097152</pre>

In recent kernels the shmall is set to 2097152 memory pages multiplied by 4096 bytes per page for a total of 8 GB of shared memory available. You only need to increase the shmall value if you have a computer with more than 8GB of memory and wish to use more of it for shared memory usage, such as large databases.

The most shared memory bytes you can allocate in one go :-
<pre># cat /proc/sys/kernel/shmmax
33554432</pre>

In recent kernels the shmmax is set to 33554432 bytes for only 32 MB of maximum shared memory allocatable at a time, hardly enough for ZoneMinder to go above 320 x 240 x 24-bit resolution at 40 frames in the buffer if it is using the /dev/shm shared memory device, so this value needs to be increased. If you are using ZoneMinder with the memory mapped (mmap) compile time option then this doesn't affect you.

To change the value to 128 MB temporarily during this kernel execution type (for example) :-
<pre>echo 536870912 >/proc/sys/kernel/shmmax</pre>

'''Be sure to restart ZoneMinder after this.'''
However be aware that sometimes you will only need to change the shmmax value as shmall is often large enough. Also changing these values in this way is only effective until your machine is rebooted.

To change them permanently you will need to edit <tt>/etc/sysctl.conf</tt> and add the following lines (for example) :-
<pre>kernel.shmmax = 536870912</pre>

Or if your distribution has the <tt>/etc/sysctl.d/</tt> folder you can create a file in this folder without modifying the <tt>/etc/sysctl.d</tt> so you won't lose the changes during distro upgrades :-
<pre>echo kernel.shmmax = 536870912 >/etc/sysctl.d/60-kernel-shm.conf</pre>

To load these settings in the sysctl.conf file type:
<pre>sysctl -p</pre>

To check your shared memory settings type:
<pre>ipcs -l</pre>

Note that with Megapixel cameras like the Axis 207mw becoming cheaper and more attractive, the above memory settings are not adequate. To get Zoneminder working with a full 1280x1024 resolution camera in full color, increase <tt>134217728</tt> (128 MB) to, for example, <tt>268435456</tt> (256 MB) and multiple this value by each camera.

These changes will now also be set the next time your machine is restarted.

Versions 1.24.x of ZoneMinder also allows you to use an alternate method of shared memory allocation, [http://en.wikipedia.org/wiki/Mmap mapped memory]. This requires less configuration and can be simpler to use. Mapped memory allows you to use a special type of file as the placeholder for your memory and this file is 'mapped' into memory space for easy and fast access.

To enable mapped memory in ZoneMinder you need add add the --enable--mmap=yes switch to your configure line. By default mapped memory files are created in /dev/shm which on most distributions is a dedicated pseudo-partition containing memory formatted as a filesystem. If your system uses a different path then this can be changed in ZoneMinder in Options->paths->PATH_MAP. It uses a filesystem type called [http://en.wikipedia.org/wiki/Tmpfs tmpfs]. If you type 'df' you should see this area and the size of memory it currently allows. It is important that you do not use a disk based filesystem for your memory mapped files as this will cause memory access to be extremely slow. ZoneMinder creates files called .zm.mmap.<monitor id> in the mapped memory filesystem.

Mapped memory is subject to the same limitations in terms of total memory as using more traditional shared memory but does not require any configuration per allocation or chunk. In future versions of ZoneMinder this will be the default shared memory storage method.

<div id="AlternateSharedMemory" style="width:80%; border:2px solid #8a8588; background:#faf5ff; vertical-align:top; margin-top: 6px; padding: 4px;">
Another good article about shared memory settings http://publib.boulder.ibm.com/infocenter/db2luw/v9/index.jsp?topic=/com.ibm.db2.udb.uprun.doc/doc/t0008238.htm .
It made a statement that conflicted with those in the Redhat article but they fixed a [http://www.zoneminder.com/forums/viewtopic.php?t=9692 long standing memory issue on FC6], so give them a try.

'''The essential difference was that the kernel.shmall setting is NOT in a direct memory setting in KB but in pages of memory. it is Max Pages of memory'''

'''For example:''' If you want to allocate a maximum memory setting to 8GB you have to convert it to the number of pages (or segments).
with a page size of 4096.
*kernel.shmall = 8000x1024x1024/4096
<pre>kernel.shmall = 2097152</pre>
NOT 8388608000 as would be suggested in the RedHat article linked above.

shmmax is the max amount to allocate in one request -
this is is an actual memory size (as opposed to pages) set to 4GB
<pre>kernel.shmmax = 4294967296</pre>

The <tt>/etc/sysctl.conf</tt> would have these lines
<pre>kernel.shmall = 2097152
kernel.shmmax = 4294967296</pre>

As above, reload your sysctl.conf with <tt>sysctl -p</tt> and check that the settings are correct with <tt>ipcs -l</tt>.
</div>

===I have enabled motion detection but it is not always being triggered when things happen in the camera view===

ZoneMinder uses zones to examine images for motion detection. When you create the initial zones you can choose from a number of preset values for sensitivity etc. Whilst these are usually a good starting point they are not always suitable for all situations and you will probably need to tweak the values for your specific circumstances. The meanings of the various settings are described in the documentation (http://www.zoneminder.com/wiki/index.php/Documentation#Defining_Zones) however if you believe you have sensible settings configured then there are two diagnostic approaches you can use.

====Event Statistics====
The first technique is to use event statistics. Firstly you should ensure they are switched on in Options->Logging->RECORD_EVENT_STATS. This will then cause the raw motion detection statistics for any subsequently generated events to be written to the DB. These can then be accessed by first clicking on the Frames or Alarm Frames values of the event from any event list view in the web gui. Then click on the score value to see the actual values that caused the event. Alternatively the stats can be accessed by clicking on the 'Stats' link when viewing any individual frame. The values displayed there correspond with the values that are used in the zone configuration and give you an idea of what 'real world' values are being generated.

Note that if you are investigating why events 'do not' happen then these will not be saved and so won't be accessible. The best thing to do in that circumstance is to make your zone more sensitive so that it captures all events (perhap even ones you don't want) so you can get an idea of what values are being generated and then start to adjust back to less sensitive settings if necessary. You should make sure you test your settings under a variety of lighting conditions (e.g. day and night, sunny or dull) to get the best feel for that works and what doesn't.

Using statistics will slow your system down to a small degree and use a little extra disk space in the DB so once you are happy you can switch them off again. However it is perfectly feasible to keep them permanently on if your system is able to cope which will allow you to review your setting periodically.

====Diagnostic Images====
The second approach is to use diagnostic images which are saved copies of the intermediate images that ZM uses when determining motion detection. These are switched on and off using Options->Logging->RECORD_DIAG_IMAGES.

There are two kinds of diagnostic images which are and are written (and continuously overwritten) to the top level monitor event directory. If an event occurs then the files are additionally copied to the event directory and renamed with the appropriate frame number as a prefix.

The first set are produced by the monitor on the image as a whole. The diag-r.jpg image is the current reference image against which all individual frames are compared and the diag-d.jpg image is the delta image highlighting the difference between the reference image and the last analysed image. In this images identicial pixels will be black and the more different a pixel is the whiter it will be. Viewing this image and determining the colour of the pixels is a good way of getting a feel for the pixel differences you might expect (often more than you think).

The second set of diag images are labelled as diag-<zoneid>-<stage>.jpg where zoneid is the id of the zone in question (Smile) and the stage is where in the alarm check process the image is generated from. So if you have several zones you can expect to see multiple files. Also these files are only interested in what is happening in their zone only and will ignore anything else outside of the zone. The stages that each number represents are as follows,

# Alarmed Pixels - This image shows all pixels in the zone that are considered to be alarmed as white pixels and all other pixels as black.
# Filtered Pixels - This is as stage one except that all pixels removed by the filters are now black. The white pixels represent the pixels that are candidates to generate an event.
# Raw Blobs - This image contains all alarmed pixels from stage 2 but aggrageted into blobs. Each blob will have a different greyscale value (between 1 and 254) so they can be difficult to spot with the naked eye but using a colour picker or photoshop will make it easier to see what blob is what.
# Filtered Blobs - This image is as stage 3 but under (or over) sized blobs have been removed. This is the final step before determining if an event has occurred, just prior to the number of blobs being counted. Thus this image forms the basis for determining whether an event is generated and outlining on alarmed images is done from the blobs in this image.

Using the above images you should be able to tell at all stages what ZM is doing to determine if an event should happen or not. They are useful diagnostic tools but as is mentioned elsewhere they will massively slow your system down and take up a great deal more space. You should never leave ZM running for any length of time with diagnostic images on.

===Why can't ZoneMinder capture images (either at all or just particularly fast) when I can see my camera just fine in xawtv or similar?===

With capture cards ZoneMinder will pull images as fast as it possibly can unless limited by configuration. ZoneMinder (and any similar application) uses the frame grabber interface to copy frames from video memory into user memory. This takes some time, plus if you have several inputs sharing one capture chip it has to switch between inputs between captures which further slows things down.

On average a card that can capture at 25fps per chip PAL for one input will do maybe 6-10fps for two, 1-4fps for three and 1-2 for four. For a 30fps NTSC chip the figures will be correspondingly higher. However sometimes it is necessary to slow down capture even further as after an input switch it may take a short while for the new image to settle before it can be captured without corruption.

When using xawtv etc to view the stream you are not looking at an image captured using the frame grabber but the card's video memory mapped onto your screen. This requires no capture or processing unless you do an explicit capture via the J or ctrl-J keys for instance. Some cards or drivers do not support the frame grabber interface at all so may not work with ZoneMinder even though you can view the stream in xawtv. If you can grab a still using the grab functionality of xawtv then in general your card will work with ZoneMinder.

===Why can't I see streamed images when I can see stills in the Zone window etc?===

This issue is normally down to one of two causes

1) You are using Internet Explorer and are trying to view multi-part jpeg streams. IE does not support these streams directly, unlike most other browsers. You will need to install Cambozola or another multi-part jpeg aware pluging to view them. To do this you will need to obtain the applet from the Downloads page and install the cambozola.jar file in the same directly as the ZoneMinder php files. Then find the ZoneMinder Options->Images page and enable ZM_OPT_CAMBOZOLA and enter the web path to the .jar file in ZM_PATH_CAMBOZOLA. This will ordinarily just be cambozola.jar. Provided ZM_CAN_STREAM is set to auto and ZM_STREAM_METHOD is set to jpeg then Cambozola should be loaded next time you try and view a stream.

'''NOTE''': If you find that the Cambozola applet loads in IE but the applet just displays the version # of Cambozola and the author's name (as opposed to seeing the streaming images), you may need to chmod (''-rwxrwxr-x'') your (''usr/share/zoneminder/'') cambozola.jar:

$ sudo chmod 775 cambozola.jar

Once I did this, images started to stream for me.

2) The other common cause for being unable to view streams is that you have installed the ZoneMinder cgi binaries (zms and nph-zms) in a different directory than your web server is expecting. Make sure that the --with-cgidir option you use to the ZoneMinder configure script is the same as the CGI directory configure for your web server. If you are using Apache, which is the most common one, then in your httpd.conf file there should be a line like <pre>ScriptAlias /cgi-bin/ "/var/www/cgi-bin/"</pre> where the last directory in the quotes is the one you have specified. If not then change one or the other to match. Be warned that configuring apache can be complex so changing the one passed to the ZoneMinder configure (and then rebuilding and reinstalling) is recommended in the first instance. If you change the apache config you will need to restart apache for the changes to take effect. If you still cannot see stream reliably then try changing Options->Paths->ZM_PATH_ZMS to just use zms if nph-zms is specified, or vice versa. Also check in your apache error logs.

===I have several monitors configured but when I load the Montage view in FireFox why can I only see two? or, Why don't all my cameras display when I use the Montage view in FireFox?===

By default FireFox only supports a small number of simultaneous connections. Using the montage view usually requires one persistent connection for each camera plus intermittent connections for other information such as statuses.

You will need to increase the number of allowed connections to use the montage view with more than a small number of cameras. Certain FireFox extensions such as FasterFox may also help to achieve the same result.

To resolve this situation, follow the instructions below:

<pre>Enter about:config in the address bar

scroll down to
browser.cache.check_doc_frequency 3
change the 3 to a 1

browser.cache.disk.enable True -> False
network.http.max-connections-per-server -> put a value of 100
network.http.max-persistent-connections-per-proxy -> 100 again
network.http.max-persistent-connections-per-server -> 100 again
</pre>

===Why is ZoneMinder using so much CPU?===

The various elements of ZoneMinder can be involved in some pretty intensive activity, especially while analysing images for motion. However generally this should not overwhelm your machine unless it is very old or underpowered.

There are a number of specific reasons why processor loads can be high either by design or by accident. To figure out exactly what is causing it in your circumstances requires a bit of experimentation.

The main causes are.

# Using a video palette other than greyscale or RGB24. This can cause a relatively minor performace hit, though still significant. Although some cameras and cards require using planar palettes ZM currently doesn't support this format internally and each frame is converted to an RGB representation prior to processing. Unless you have compelling reasons for using YUV or reduced RGB type palettes such as hitting USB transfer limits I would experiment to see if RGB24 or greyscale is quicker. Put your monitors into 'Monitor' mode so that only the capture daemons are running and monitor the process load of these (the 'zmc' processes) using top. Try it with various palettes to see if it makes a difference.
# Big image sizes. A image of 640x480 requires at least four times the processing of a 320x240 image. Experiment with different sizes to see what effect it may have. Sometimes a large image is just two interlaced smaller frames so has no real benefit anyway. This is especially true for analog cameras/cards as image height over 320 (NTSC) or 352 PAL) are invariably interlaced.
# Capture frame rates. Unless there's a compelling reason in your case there is often little benefit in running cameras at 25fps when 5-10fps would often get you results just as good. Try changing your monitor settings to limit your cameras to lower frame rates. You can still configure ZM to ignore these limits and capture as fast as possible when motion is detected.
# Run function. Obviously running in Record or Mocord modes or in Modect with lots of events generates a lot of DB and file activity and so CPU and load will increase.
# Basic default detection zones. By default when a camera is added one detection zone is added which covers the whole image with a default set of parameters. If your camera covers a view in which various regions are unlikely to generate a valid alarm (ie the sky) then I would experiment with reducing the zone sizes or adding inactive zones to blank out areas you don't want to monitor. Additionally the actual settings of the zone themselves may not be optimal. When doing motion detection the number of changed pixels above a threshold is examined, then this is filter, then contiguous regions are calculated to see if an alarm is generated. If any maximum or minimum threshold is exceeded according to your zone settings at any time the calculation stops. If your settings always result in the calculations going through to the last stage before being failed then additional CPU time is used unnecessarily. Make sure your maximum and minimumzone thresholds are set to sensible values and experiment by switching RECORD_EVENT_STATS on and seeing what the actual values of alarmed pixels etc are during sample events.
# Optimise your settings. After you've got some settings you're happy with then switching off RECORD_EVENT_STATS will prevent the statistics being written to the database which saves some time. Other settings which might make a difference are ZM_FAST_RGB_DIFFS, ZM_OPT_FRAME_SERVER and the JPEG_xxx_QUALITY ones.

I'm sure there are other things which might make a difference such as what else you have running on the box and memory sizes (make sure there's no swapping going on). Also speed of disk etc will make some difference during event capture and also if you are watching the whole time then you may have a bunch of zms processes running also.

I think the biggest factors are image size, colour depth and capture rate. Having said that I also don't always know why you get certains results from 'top'. For instance if I have a 'zma' daemon running for a monitor that is capturing an image. I've commented out the actual analysis so all it's doing is blending the image with the previous one. In colour mode this takes ~11 milliseconds per frame on my system and the camera is capturing at ~10fps. Using 'top' this reports the process as using ~5% of CPU and permanently in R(un) state. Changing to greyscale mode the blending takes ~4msec (as you would expect as this is roughly a third of 11) but top reports the process as now with 0% CPU and permanently in S(leep) state. So an actual CPU resource usage change of a factor of 3 causes huge differences in reported CPU usage. I have yet to get to the bottom of this but I suspect it's to do with scheduling somewhere along the line and that maybe the greyscale processing will fit into one scheduling time slice whereas the colour one won't but I have no evidence of this yet!

===Why is the timeline view all messed up?===

The timeline view is a new view allowing you to see a graph of alarm activity over time and to quickly scan and home in on events of interest. However this feature is highly complex and still in beta. It is based extensively on HTML div tags, sometimes lots of them. Whilst FireFox is able to render this view successfully other browsers, particular Internet Explorer do not seem able to cope and so present a messed up view, either always or when there are a lot of events.
Using the timeline view is only recommended when using FireFox, however even then there may be issues.

This function has from time to time been corrupted in the SVN release or in the stable releases, try and reinstall from a fresh download.

===How much Hard Disk Space / Bandwidth do I need for ZM?===
Please see [http://www.jpwilson.eu/ZM_Utils/ZM%20storage%20calc%20sheet.xls Storage Calc] in excel format

Or go to [http://www.axis.com/products/video/design_tool/index.htm this link] for the Axis bandwidth calculator. Although this is aimed at Axis cameras it still produces valid results for any kind of IP camera.

As a quick guide I have 4 cameras at 320x240 storing 1 fps except during alarm events. After 1 week 60GB of space in the volume where the events are stored (/var/www/html/zm) has been used.

===When I try and run ZoneMinder I get lots of audit permission errors in the logs and it won't start===
Many Linux distributions nowadays are built with security in mind. One of the latest methods of achieving this is via SELinux (Secure Linux) which controls who is able to run what in a more precise way then traditional accounting and file based permissions ([http://en.wikipedia.org/wiki/Selinux]).
If you are seeing entries in your system log like:

Jun 11 20:44:02 kernel: audit(1150033442.443:226): avc: denied { read } for pid=5068
comm="uptime" name="utmp" dev=dm-0 ino=16908345 scontext=user_u:system_r:httpd_sys_script_t
tcontext=user_u:object_r:initrc_var_run_t tclass=file

then it is likely that your system has SELinux enabled and it is preventing ZoneMinder from performaing certain activities. You then have two choices. You can either tune SELinux to permit the required operations or you can disable SELinux entirely which will permit ZoneMinder to run unhindered. Disabling SELinux is usually performed by editing it's configuration file (e.g., <tt>/etc/selinux/config</tt>) and then rebooting. However if you run a public server you should read up on the risks associated with disabled Secure Linux before disabling it.

Note that SELinux may cause errors other than those listed above. If you are in any doubt then it can be worth disabling SELinux experimentally to see if it fixes your problem before trying other solutions.

=== How do I enable ZoneMinder's security? ===
In the console, click on Options. Check the box next to "ZM_OPT_USE_AUTH". You will immediately be asked to login. The username is 'admin' and the password is 'admin'.

'''To Manage Users:''' 
In main console, go to '''Options->Users'''.

* You may also consider to use the web server security, for example, htaccess files under Apache scope; You may even use this as an additional/redundant security on top of Zoneminders built-in security features;

=== Why does ZM stop recording once I have 32000 events for my monitor? ===
This is a limitation of the ext3 filesystem that most Linux distributions use. One directory cannot hold more than 32k approx files.

Version of ZM from 1.23.0 onwards allow you to have a deeper filesystem with fewer files per individual directory. As well as not being susceptible to the 32k limit this is also somewhat faster. However it is relatively and although few issues have been reported thus far it should be considered in beta for now. Also, it is currently not possible to migrate saved events between the different storage formats so is only suitable for new installations or if you do not mind losing saved events.

So if you do not want to use the deeper filesystem option
(Options->Paths->ZM_USE_DEEP_STORAGE), for now you have to reduce the
number of events or store your images (e.g. /var/lib/zoneminder) on a
partition that uses a different filesystem such as ext4 or reiserfs.

You can read about the lack of a limit in the number of
sub-directories in the ext4 filesystem at:
http://kernelnewbies.org/Ext4
and see what tools may assist in your use of this filesystem in:
http://ext4.wiki.kernel.org/index.php/Ext4_Howto
Note that while GParted 0.5.2 recognizes ext4 partitions, at least in
some circumstances it does not succeed in formatting a partition for
the ext4 filesystem. Also, if you search for ext3 or reiserfs on the
forums you will find various threads on this issue with guidance on
how to convert.

== Managing system load ''(with IP Cameras in mind)'' ==

=== Introduction ===
Zoneminder is a superb application in every way, but it does a job that needs a lot of horsepower especially when using multiple IP cameras. IP Cams require an extra level of processing to analogue cards as the jpg or mjpeg images need to be decoded before analysing. This needs grunt. If you have lots of cameras, you need lots of grunt.

Why do ZM need so much grunt?
Think what Zoneminder is actually doing. In modect mode ZM is:
1. Fetching a jpeg from the camera. (Either in single part or multipart stream)
2. Decoding the jpeg image.
3. Comparing the zoned selections to the previous image or images and applying rules.
4. If in alarm state, writing that image to the disk and updating the mysql database.

If you're capturing at five frames per second, the above is repeated five times every second, multiplied by the number of cameras. Decoding the images is what takes the real power from the processor and this is the main reason why analogue cameras which present an image ready-decoded in memory take less work.

=== How do I know if my computer is overloaded? ===
If your CPU is running at 100% all the time, it's probably overloaded (or running at exact optimisation). If the load is consistently high (over 10.0 for a single processor) then Bad Things happen - like lost frames, unrecorded events etc. Occasional peaks are fine, normal and nothing to worry about.

Zoneminder runs on Linux, Linux measures system load using "load", which is complicated but gives a rough guide on what the computer is doing at any given time. Zoneminder shows Load on the main page (top right) as well as disk space. Typing "uptime" on the command line will give a similar guide, but with three figures to give a fuller measure of what's happening over a period of time but for the best guide to see what's happening, install "htop" - which gives easy to read graphs for load, memory and cpu usage.

A load of 1.0 means the processor has "just enough to do right now". Also worth noting that a load of 4.0 means exactly the same for a quad processor machine - each number equals a single processor's workload. A very high load can be fine on a computer that has a stacked workload - such as a machine sending out bulk emails, or working its way through a knotty problem; it'll just keep churning away until it's done. However - Zoneminder needs to process information in real time so it can't afford to stack its jobs, it needs to deal with them right away.

For a better and full explanation of Load: http://en.wikipedia.org/wiki/Load_%28computing%29

=== My load is too high, how can I reduce it? ===
Zoneminder is /very/ tweakable and it's possible to tune it to compromise. The following are good things to try, in no particular order;

Change the jpeg libraries. In most distributions Linux uses standard jpeg libraries which although fine for most things, don't use the MMX functions in nearly all modern processors. Check whether your cpu supports mmx by running "cpuid |grep MMX" which should give you a line or two along the lines of "MMX instructions". If so, give the libs a try. Most people report their load halves simply by using these libs. You may be able to experience substantial Zoneminder performance boosts now by merely upgrading your operating system, without having to download libraries and compile your own binaries, etc. as described in the forum thread linked below. Some distributions, e.g. Fedora 14 now include library code to utilize the instruction set extensions available in your processor:

http://fedoraproject.org/wiki/Fedora_14_Alpha_release_notes#Faster_JPEG_Compression.2FDecompression

"The replacement of libjpeg with libjpeg-turbo brings speed improvements to a wide range of applications when handling images in JPEG format ..."

http://fedoraproject.org/wiki/Releases/14/Schedule

still states "2010-11-02 final release".

CentOS 6.4 now has libjpeg-turbo built in as the default jpeg library allowing the best results out of the box.

http://libjpeg-turbo.virtualgl.org/

provides some history on its project page. If you seek confirmation for which library is in use, you may consider querying e.g. while running on a prior distribution:
<pre>
[u@who ~]$ rpm -q --whatprovides libjpeg
libjpeg-6b-46.fc12.i686
[u@who ~]$
</pre>
and comparing the response to querying when the higher-performance library is available:
<pre>
[u@who ~]$ rpm -q --whatprovides libjpeg
libjpeg-turbo-1.0.1-1.fc14.x86_64
[u@who ~]$
</pre>
As noted in other forum postings, some zoneminder camera and usage configurations may not make much use of jpeg processing (e.g. some webcams), and thus obtain little performance benefit. Otherwise, you should be able to select one or more of:
* running more cameras,
* running existing cameras at higher image resolutions,
* running cameras at a faster frame rate,
* saving MoDect images with higher quality,
* having more CPU cycles available for any non-Zoneminder workload, etc.

http://www.zoneminder.com/forums/viewtopic.php?t=6419 gives more info on the download-the-library-yourself, compile-your-own-Zoneminder binary, etc. approach if needed. Nobody's posted there to say it broke their system... Yet.

If your camera allows you to change image size, think whether you can get away with smaller images. Smaller pics = less load. 320x240 is usually ok for close-up corridor shots.

Go Black and White. Colour pictures use twice to three times the CPU, memory and diskspace but give little benefit to identification.

Reduce frames per second. Halve the fps, halve the workload. If your camera supports fps throttling (Axis do), try that - saves ZM having to drop frames from a stream. 2-5 fps seems to be widely used.

Experiment with using jpeg instead of mjpeg. Some users have reported it gives better performance, but YMMV.

Tweak the zones. Keep them as small and as few as possible. Stick to one zone unless you really need more.

Schedule. If you are running a linux system at near capacity, you'll need to think carefully about things like backups and scheduled tasks. updatedb - the process which maintains a file database so that 'locate' works quickly, is normally scheduled to run once a day and if on a busy system can create a heavy increase on the load. The same is true for scheduled backups, especially those which compress the files. Re-schedule these tasks to a time when the cpu is less likely to be busy, if possible - and also use the "nice" command to reduce their priority. (crontab and /etc/cron.daily/ are good places to start)

Reduce clutter on your PC. Don't run X unless you really need it, the GUI is a huge overhead in both memory and cpu.

More expensive options:

Increase RAM. If your system is having to use disk swap it will HUGELY impact performance in all areas. Again, htop is a good monitor - but first you need to understand that because Linux is using all the memory, it doesn't mean it needs it all - linux handles ram very differently to Windows/DOS and caches stuff. htop will show cached ram as a different colour in the memory graph. Also check that you're actually using a high memory capable kernel - many kernels don't enable high memory by default.

Faster CPU. Simple but effective. Zoneminder also works very well with multiple processor systems out of the box (if SMP is enabled in your kernel). The load of different cameras is spread across the processors.

Try building Zoneminder with processor specific instructions that are optimised to the system it will be running on, also increasing the optimisation level of GCC beyond -O2 will help.
<pre>
./configure CFLAGS="-g -O3 -march=athlon-xp -mtune=athlon-xp" CXXFLAGS="-g -O3 -march=athlon-xp -mtune=athlon-xp"
</pre>
The above command is optimised for an Athlon XP cpu so you will need to use the specific processor tag for your cpu, also the compiler optimisation has been increased to -O3.

You also need to put in your normal ./configure commands as if you were compiling with out this optimisation.

A further note is that the compile must be performed on the system that Zoneminder will be running on as this optimisation will make it hardware specific code.

Processor specific commands can be found in the GCC manual along with some more options that may increase performanc.
<pre>
http://gcc.gnu.org/onlinedocs/gcc/i386-and-x86_002d64-Options.html#i386-and-x86_002d64-Options
</pre>

The below command has been used to compile Zoneminder on a Athlon XP system running CentOS 5.5 and along with the libjpeg-turbo modification to reduce the CPU load in half, libjpeg-turbo reduced the load by 1/3 before the processor optimisation.
<pre>
./configure --with-webdir=/var/www/html/zm --with-cgidir=/var/www/cgi-bin CFLAGS="-g -O3 -march=athlon-xp -mtune=athlon-xp" CXXFLAGS="-D__STDC_CONSTANT_MACROS -g -O3 -march=athlon-xp -mtune=athlon-xp" --enable-mmap --sysconfdir=/etc/zm
</pre>

The following command has been used to compile Zoneminder 1.25 on a CentOS 6.0 system, the native command should choose the processor automatically during compile time, this needs to be performed on the actual system!!.

<pre>
CFLAGS="-g -O3 -march=native -mtune=native" CXXFLAGS="-D__STDC_CONSTANT_MACROS -g -O3 -march=native -mtune=native" ./configure --with-webdir=/var/www/html/zm --with-cgidir=/var/www/cgi-bin --with-webuser=apache --with-webgroup=apache ZM_DB_HOST=localhost ZM_DB_NAME=zm ZM_DB_USER=your_zm_user ZM_DB_PASS=your_zm_password ZM_SSL_LIB=openssl
</pre>

=== What about disks and bandwidth? ===

In most modern pc-based servers, disk I/O is more than adequate for the speeds involved in capturing from multiple cameras in most scenarios.

A typical 100mbit LAN will cope with most setups easily. If you're feeding from cameras over smaller or internet links, obviously fps will be much lower.

Disk and Bandwidth calculators are referenced on the Zoneminder wiki here: http://www.zoneminder.com/wiki/index.php/FAQ#How_much_Hard_Disk_Space_.2F_Bandwidth_do_I_need_for_ZM.3F

== Building ZoneMinder ==

=== When running configure I am getting a lot of messages about not being able to compile the ffmpeg libraries ===

If you see output from configure that looks like this

<pre>checking libavcodec/avcodec.h usability... no
checking libavcodec/avcodec.h presence... yes
configure: WARNING: libavcodec/avcodec.h: present but cannot be compiled
configure: WARNING: libavcodec/avcodec.h: check for missing
prerequisite headers?
configure: WARNING: libavcodec/avcodec.h: see the Autoconf documentation
configure: WARNING: libavcodec/avcodec.h: section "Present But
Cannot Be Compiled"
configure: WARNING: libavcodec/avcodec.h: proceeding with the compiler's
result
configure: WARNING: ## ------------------------------------- ##
configure: WARNING: ## Report this to support@zoneminder.com ##
configure: WARNING: ## ------------------------------------- ##</pre>

then it is caused not by the ZoneMinder build system but ffmpeg itself. However there is a workaround you can use which is to add

CPPFLAGS=-D__STDC_CONSTANT_MACROS

to the ZoneMinder ./configure command which should solve the issue. However this is not a proper 'fix' as such, which can only come from the ffmpeg project itself.

=== I cannot build ZoneMinder and am getting lots of undefined C++ template errors===

This is almost certainly due to the 'ccache' package which attempts to speed up compilation by caching compiled objects. Unfortunately one of the side effects is that it breaks the GNU g++ template resolution method that ZoneMinder uses in building by prevent files getting recompiled. The simplest way around this is to remove the ccache package using your distros package manager.

=== How do I build for X10 support? ===

You do not need to rebuild ZM for X10 support. You will need to install the perl module and switch on X10 in the options, then restart. Installing the perl module is covered in the README amongst other places but in summary, do:

perl -MCPAN -eshell
install X10::ActiveHome
quit

== Extending ZoneMinder ==

=== How can I get ZM to do different things at different times of day or week? ===
If you want to configure ZoneMinder to do motion detection during the day and just record at night, for example, you will need to use ZoneMinder 'run states'. A run state is a particular configuration of monitor functions that you want to use at any time.

To save a run state you should first configure your monitors for Modect, Record, Monitor etc as you would want them during one of the times of day. Then click on the running state link at the top of the Console view. This will usually say 'Running' or 'Stopped'. You will then be able to save the current state and give it a name, 'Daytime' for example. Now configure your monitors how you would want them during other times of day and save that, for instance as 'Nighttime'.

Now you can switch between these two states by selecting them from the same dialog you saved them, or from the command line from issue the command ''zmpkg.pl <run state>'', for example ''zmpkg.pl Daytime''.

The final step you need to take, is scheduling the time the changes take effect. For this you can use [http://en.wikipedia.org/wiki/Cron cron]. A simple entry to change to the Daylight state at at 8am and to the nighttime state at 8pm would be as follows,
<pre>0 8 * * * root /usr/local/bin/zmpkg.pl Daytime
0 20 * * * root /usr/local/bin/zmpkg.pl Nighttime</pre>

On Ubuntu 7.04 and possibly others, look in /usr/bin not just /usr/local/bin for the zmpkg.pl file.

Although the example above describes changing states at different times of day, the same principle can equally be applied to days of the week or other more arbitrary periods.

For an alternative method of time controlling ZoneMinder, forum user 'voronwe' has created a more interactive calendar style integration. Details of this can be found in this [http://www.zoneminder.com/forums/viewtopic.php?t=6519 forum thread]. If you would like to find out more about this contribution please post on this thread.

=== How can I use ZoneMinder to trigger something else when there is an alarm? ===
ZoneMinder includes a perl API which means you can create a script to interact with the ZM shared memory data and use it in your own scripts to react to ZM alarms or to trigger ZM to generate new alarms. Full details are in the README or by doing 'perldoc ZoneMinder', 'perldoc ZoneMinder::SharedMem' etc.
Below is an example script that checks all monitors for alarms and when one occurs, prints a message to the screen. You can add in your own code to make this reaction a little more useful.

<pre>#!/usr/bin/perl -w

use strict;

use ZoneMinder;

$| = 1;

zmDbgInit( "myscript", level=>0, to_log=>0, to_syslog=>0, to_term=>1 );

my $dbh = DBI->connect( "DBI:mysql:database=".ZM_DB_NAME.";host=".ZM_DB_HOST, ZM_DB_USER, ZM_DB_PASS );

my $sql = "select M.*, max(E.Id) as LastEventId from Monitors as M left join Events as E on M.Id = E.MonitorId where M.Function != 'None' group by (M.Id)";
my $sth = $dbh->prepare_cached( $sql ) or die( "Can't prepare '$sql': ".$dbh->errstr() );

my $res = $sth->execute() or die( "Can't execute '$sql': ".$sth->errstr() );
my @monitors;
while ( my $monitor = $sth->fetchrow_hashref() )
{
push( @monitors, $monitor );
}

while( 1 )
{
foreach my $monitor ( @monitors )
{
next if ( !zmMemVerify( $monitor ) );

if ( my $last_event_id = zmHasAlarmed( $monitor, $monitor->{LastEventId} ) )
{
$monitor->{LastEventId} = $last_event_id;
print( "Monitor ".$monitor->{Name}." has alarmed\n" );
#
# Do your stuff here
#
}
}
sleep( 1 );
}</pre>

==Trouble Shooting==
Here are some things that will help you track down whats wrong.
This is also how to obtain the info that we need to help you on the forums.

===What logs should I check for errors?===
ZoneMinder creates its own logs and are usually located in the <tt>/tmp</tt> directory.

The ZoneMinder logs for the RPM packages are located in <tt>/var/log/zm</tt>.

Depending on your problem errors can show up in any of these logs but, usually the logs of interest are <tt>zmdc.log</tt> and <tt>zmpkg.log</tt> if ZM is not able to start.

Now since ZM is dependent on other components to work, you might not find errors in ZM but in the other components.
Other logs of interest are:<tt>
*/var/log/messages and/or /var/log/syslog
*/var/log/dmesg
*/var/log/httpd/error_log</tt> (RedHat/Fedora) or <tt>/var/log/apache2/error_log
*/var/log/mysqld.log</tt> (Errors here don't happen very often but just in case)

If ZM is not functioning, you should always be able to find an error in at least one of these logs. Use the [[tail]] command to get info from the logs. This can be done like so:

tail -f /var/log/messages /var/log/httpd/error_log /var/log/zm/zm*.log

This will append any data entered to any of these logs to your console screen (<tt>-f</tt>). To exit, hit [ctrl -c].

More verbose logging for the ZoneMinder binaries is available by enabling the debug option from the control panel and will be placed in the path you have configured for the debug logs. Output can be limited to a specific binary as described in the Debug options page under the "?" marks.

===How can I trouble shoot the hardware and/or software?===
Here are some commands to get information about your hardware. Some commands are distribution dependent.
* <tt>[[lspci]] -vv</tt> -- Returns lots of detailed info. Check for conflicting interrupts or port assignments. You can sometimes alter interrupts/ ports in bios. Try a different pci slot to get a clue if it is HW conflict (comand provided by the pciutils package).
* <tt>[[scanpci]] -v</tt> -- Gives you information from your hardware EPROM
* <tt>[[lsusb]] -vv</tt> -- Returns lots of detail about USB devices (camand provided by usbutils package).
* <tt>[[dmesg]]</tt> -- Shows you how your hardware initialized (or didn't) on boot-up. You will get the most use of this.
* <tt>[[v4l-info]]</tt> -- to see how driver is talking to card. look for unusual values.
* <tt>[[modinfo bttv]]</tt> -- some bttv driver stats.
* <tt>[[zmu]] -m 0 -q -v</tt> -- Returns various information regarding a monitor configuration.
* <tt>[[ipcs]] </tt> -- Provides information on the ipc facilities for which the calling process has read acccess.
* <tt>[[ipcrm]] </tt> -- The ipcrm command can be used to remove an IPC object from the kernel.
* <tt>cat /proc/interrupts</tt> -- This will dispaly what interrupts your hardware is using.

===Why is it that when monitoring a camera, the top portion of the image is cutoff and appears at the bottom of the image, with a line seperating the top from the bottom?===

=== Why am I getting a 403 access error with my web browser when trying to access http //localhost/zm? ===

The apache web server needs to have the right permissions and configuration to be able to read the Zoneminder files. Check the forums for solution, and edit the apache configuration and change directory permissions to give apache the right to read the Zoneminder files. Depending on your Zoneminder configuration, you would use the zm user and group that Zoneminder was built with, such as wwwuser and www.

=== Why am I getting broken images when trying to view events? ===

Zoneminder and the Apache web server need to have the right permissions. Check this forum topic and similar ones:
http://www.zoneminder.com/forums/viewtopic.php?p=48754#48754

===Why is the image from my color camera appearing in black and white?===
This may occur if you have a NTSC analog camera but have configured the source in ZoneMinder as PAL for the Device Format under the source tab. You may also be mislead because zmu can report the video port as being PAL when the camera is actually NTSC. Confirm the format of your analog camera by checking it's technical specifications, possibly found with the packaging it came in, on the manufacturers website, or even on the retail website where you purchased the camera. Change the Device Format setting to NTSC and set it to the lowest resolution of 320 x 240. If you have confirmed that the camera itself is NTSC format, but don't get a picture using the NTSC setting, consider increasing the shared memory '''kernel.shmall''' and '''kernel.shmmax''' settings in /etc/sysctl.conf to a larger value such as 268435456. This is also the reason you should start with the 320x240 resolution, so as to minimize the potential of memory problems which would interfere with your attempts to troubleshoot the device format issue. Once you have obtained a picture in the monitor using the NTSC format, then you can experiment with raising the resolution.

===Why do I only see blue screens with a timestamp when monitoring my camera?===
If this camera is attached to a capture card, then you may have selected the wrong Device Source or Channel when configuring the monitor in the ZoneMinder console. If you have a capture card with 2 D-sub style inputs(looks like a VGA port) to which you attach a provided splitter that splits off multiple cables, then the splitter may be attached to the wrong port. For example, PV-149 capture cards have two D-sub style ports labeled as DB1 and DB2, and come packaged with a connector for one of these ports that splits into 4 BNC connecters. The initial four video ports are available with the splitter attached to DB1.

===Why do I only see black screens with a timestamp when monitoring my camera?===
In the monitor windows where you see the black screen with a timestamp, select settings and enter the Brightness, Contrast, Hue, and Color settings reported for the device by '''zmu -d <device_path> -q -v'''. 32768 may be appropriate values to try for these settings. After saving the settings, select Settings again to confirm they saved successfully.

===I am getting messages about a backtrace in my logs, what do I do?===
If you are seeing entries in your log like the following
<pre>Jan 11 20:25:22 localhost zma_m2[19051]: ERR [Backtrace: /lib64/libc.so.6 [0x3347230210]]
Jan 11 20:25:22 localhost zma_m2[19051]: ERR [Backtrace: /lib64/libc.so.6(memset+0xce) [0x334727684e]]
Jan 11 20:25:22 localhost zma_m2[19051]: ERR [Backtrace: /usr/local/bin/zma [0x40ee9a]]
Jan 11 20:25:22 localhost zma_m2[19051]: ERR [Backtrace: /usr/local/bin/zma [0x419946]]
Jan 11 20:25:22 localhost zma_m2[19051]: ERR [Backtrace: /usr/local/bin/zma [0x4213cf]]
Jan 11 20:25:22 localhost zma_m2[19051]: ERR [Backtrace: /usr/local/bin/zma(cos+0x35c) [0x404674]]
Jan 11 20:25:22 localhost zma_m2[19051]: ERR [Backtrace: /lib64/libc.so.6(__libc_start_main+0xf4) [0x334721da44]]
Jan 11 20:25:22 localhost zma_m2[19051]: ERR [Backtrace: /usr/local/bin/zma(cos+0xd1) [0x4043e9]]
Jan 11 20:25:22 localhost zma_m2[19051]: INF [Backtrace complete]</pre>
then you can help diagnose the problem by running a special command to translate the hex addresses into helpful information. This command is called addr2line and you can type 'man addr2line' for more information.
Basically addr2line takes two sets of parameters, the first is the name of the binary file, and the second is a list of addresses. Both of these pieces of information are displayed in the logs. The filename is the first part after the 'Backtrace:' tag, in this case /usr/local/bin/zma, though it may well be different in your case. Some of the lines refer to libraries rather than the zma executable but those can be ignored for now, the important part is noting which ZM binary is involved. The binary file is passed in following the -e flag. The addresses to pass to addr2line are those contained in the '[]' pairs. Again you can ignore those that are on a line that refers to a library but it will not hurt if you include them.
So in the example above, the command would be <pre>addr2line -e /usr/local/bin/zma 0x40ee9a 0x419946 0x4213cf 0x404674 0x4043e9</pre>
This should then dump out a more symbolic list containing source file names and line numbers, and it is this information which will be helpful if posted to the forums. Sometimes addr2line fails to produce useful output. This is usually because either the problem is so severe that it has corrupted the stack and prevented useful information from being displayed, or that you have either compiled ZM without the -g flag for debug, or you have stripped the binaries of symbol information after installation. This this case you would need to rebuild temporarily with debug enabled for the information to be useful.

This error some times happens when a linked camera looses its link or it is corrupted by the user or some other system event, try deleting the affected cameras and recreating them in the Zoneminder console.

===How do I repair the MySQL Database?===
There is two ways to go about this. In most cases you can run from the command prompt ->
* mysqlcheck --all-databases --auto-repair -p'''your_database_password''' -u '''your_databse_user'''

If that does not work then you will have to make sure that ZoneMinder is stopped then run the following (nothing should be using the database while running this and you will have to adjust for your correct path if it is different). ->
* myisamchk --silent --force --fast --update-state -O key_buffer=64M -O sort_buffer=64M -O read_buffer=1M -O write_buffer=1M /var/lib/mysql/*/*.MYI

===How do I repair the MySQL Database when the cli fails?===
In Ubuntu, the commands listed above do not seem to work. However, actually doing it by hand from within MySQL does. (But that is beyond the scope of this document) But that got me thinking... And phpmyadmin does work. Bring up a terminal.
sudo apt-get install phpmyadmin

Now go to http://zoneminder_IP/ and stop the ZM service. Continue to http://zoneminder_IP/phpmyadmin and select the zoneminder database. Select and tables marked 'in use' and pick the action 'repare' to fix. Restart the zoneminder service from the web browser. Remove or disable the phpmyadmin tool, as it is not always the most secure thing around, and opens your database wide to any skilled hacker.
sudo apt-get remove phpmyadmin

===I upgraded by distribution and ZM stopped working===
Some possibilties (Incomplete list and subject to correction)
#[[/usr/local/bin/zmfix: /usr/lib/libmysqlclient.so.15: version `MYSQL_5.0' not found (required by /usr/local/bin/zmfix)]] :: Solution: Recompile and reinstall Zoneminder.
Any time you update a major version that ZoneMinder depends on, you need to recompile ZoneMinder.

===Zoneminder doesn't start automatically on boot===
Check the list for log entries like "zmfix[766]: ERR [Can't connect to server: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)] ".
What can happen is that zoneminder is started too quickly after Mysql and tries to contact the database server before it's ready. Zoneminder gets no answer and aborts.
August 2010 - Ubuntu upgrades seem to be leaving several systems in this state. One way around this is to add a delay to the zoneminder startup script allowing Mysql to finish starting.
"Simply adding 'sleep 15' in the line above 'zmfix -a' in the /etc/init.d/zoneminder file fixed my ZoneMinder startup problems!" - credit to Pada.

=== Remote Path setup for Panasonic and other Camera ===
On adding or editing the source you can select the preset link for the parameters for the specified camera . In version 1.23.3 presets for BTTV,Axis,Panasonic,GadSpot,VEO, and BlueNet are available . Selecting the presets ZM fills up the required value for the remote path variable

=== Why do I get repeated/ mixed/unstable/ blank monitors on bt878-like cards (a.k.a. PICO 2000) ===

Please have a check at [[Pico2000]];

===What causes "Invalid JPEG file structure: two SOI markers" from zmc (1.24.x)===

Some settings that used to be global only are now per camera. On the Monitor Source tab, if you are using Remote Protocol "HTTP" and Remote Method "Simple", try changing Remote Method to "Regexp".

== Miscellaneous ==
=== I see ZoneMinder is licensed under the GPL. What does that allow or restrict me in doing with ZoneMinder? ===

The ZoneMinder license is described at the end of the documentation and consists of the following section

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

This means that ZoneMinder is licensed under the terms described [http://www.gnu.org/copyleft/gpl.html here]. There is a comprehensive FAQ covering the GPL at http://www.gnu.org/licenses/gpl-faq.html but in essence you are allowed to redistribute or modify GPL licensed software provided that you release your distribution or modifications freely under the same terms. You are allowed to sell systems based on GPL software. You are not allowed to restrict or reduce the rights of GPL software in your distribution however. Of course if you are just making modifications for your system locally you are not releasing changes so you have no obligations in this case. I recommend reading the GPL FAQ for more in-depth coverage of this issue.

=== Can I use ZoneMinder as part of my commercial product? ===

The GPL license allows you produce systems based on GPL software provided your systems also adhere to that license and any modifications you make are also released under the same terms. The GPL does not permit you to include ZoneMinder in proprietary systems (see http://www.gnu.org/licenses/gpl-faq.html#GPLInProprietarySystem for details). If you wish to include ZoneMinder in this kind of system then you will need to license ZoneMinder under different terms. This is sometimes possible and you will need to contact me for further details in these circumstances.

How to export download and view events

2013-05-16T12:18:36Z

Bs27975: too -> to, how to -> /i

--[[User:Stagecoach|stagecoach]] 15:34, 23 October 2010 (BST)

Go back to the [[How_To|How To]] pages...

=Prerequisites=
To export, download and view the events from ZoneMinder there are 3 prerequisites.
# Access to your ZoneMinder website.
# An application to unpack the exported files.
#* For Linux most distributions include an application like unzip or untar.
#* For Windows an excellent open source alternative to the default archive manager is [http://www.7-zip.org/download.html 7-Zip]
=Export Methods=
There are three ways to export events from ZoneMinder. Depending on what events you wish to export one of these methods will usually be superior.
==Front end interface method==
This is the easiest way to view events if you want to check all events in the hour/day/week/month or all events for a certain particular camera.
===Steps===
[[image:zm_home.png|right|thumb|caption|ZoneMinder homepage]]
[[image:eventsview.png|right|thumb|caption|Events view allows you to select which events to export]]
# Login to ZoneMinder as a user who has rights to view the desired monitor.
# From the home page you should see a table with columns labeling camera name events per hour/day/week/month/all. The very bottom column of this table totals the events across all cameras for the given hour/day etc. Click on the total events under the hour row to continue.
# You should now be on the event view page. This pages purpose is to list the events selected by your query method. From this view we are provided with many statistics about individual events. We may choose to review the events from this page by clicking on the name of the event, however for the purpose of this ''how to'' we will simply choose to export all events by selecting the check-box in the top right cell. After selecting all the events from this view we open up the export dialog by clicking the EXPORT button located in the bottom right corner.
# This export options dialog that pops up allows us to select the file type that is exported. Before clicking the export button you must first make sure too check the following settings:
##Export Event Details
##Export Frame Details
##Export File Format: Zip
[[image:zmexport.png|right|thumb|caption|Typical Export form settings]]
# Once you click the export button ZoneMinder will go through the process of packaging and formatting the events for you, this process can be quite intensive for the server if a large number of events are selected. When the process is completed a download link for a file called zmExport.zip should pop up, select save file and click ok. It is important to make a note of where you save your file as you will need to access it later.

==Event Filter==
[[image:eventfilter.png|right|thumb|caption|Events Filter form]]
The filter method of exporting events gives the user the most detail and control in the event query. As this method allows you to make very refined queries it does add some complexity to the process. To illustrate the power of this export method I will show you how Event Filter can create a custom query that is saved for future use, this custom query will select all events that have had more than 50 alarm frames on Mondays.

===Steps===
# On the bottom left side of your ZoneMinder homepage there should be a button labeled "Filter"
# The form section under the use filter select box is the area where we will define steps the event filter evaluates. To add the second step for the event filter simply click the + button on the bottom left of the field-set
## The first filter should be ''Alarm Frames'' - ''greater than'' - 50
## Your second filter should be ''and'' - ''Weekday'' - ''equal to'' - ''Monday''
# To save this event filter method click on the save button. Make sure to write in a descriptive name for the filter.
[[image:alarmfiltersave.png|right|thumb|caption|Events Filter save form box]]
# Executing the event filter after you have saved it is as simple as clicking execute at the bottom of the page.
# You should now be on the event view page. This pages purpose is too list the events selected by your query method. From this view we are provided with many statistics about individual events. We may choose to review the events from this page by clicking on the name of the event, however for the purpose of this how to we will simply choose to export all events by selecting the check-box in the top right cell. After selecting all the events from this view we open up the export dialog by clicking the EXPORT button located in the bottom right corner.
# This export options dialog that pops up allows us to select the file type that is exported. Before clicking the export button you must first make sure too check the following settings:
##Export Event Details
##Export Frame Details
##Export File Format: Zip
# Once you click the export button ZoneMinder will go through the process of packaging and formatting the events for you, this process can be quite intensive for the server if a large number of events are selected. When the process is completed a download link for a file called zmExport.zip should pop up, select save file and click ok. It is important to make a note of where you save your file as you will need to access it later.

==Individual camera export==
[[image:individualview.png|right|thumb|caption|Individual camera view allows you to select specific events]]
[[image:individualeventview.png|right|thumb|caption|From the individual event view exporting is as simple as clicking export (top left)]]
This export Method is the simplest way to check and export an individual event that has happened recently on a specific monitor
===Steps===
# From your ZoneMinder homepage open the [[individual view]] of a specific camera
# On the "watch" view of a monitor the recent events should be listed by date under the live stream. Click on an event from this list to view the individual event.
# On the individual event view page you should get a stream of the event. To export this event simply click the Export link located at the top of the page.
# This export options dialog that pops up allows us to select the file type that is exported. Before clicking the export button you must first make sure too check the following settings:
##Export Event Details
##Export Frame Details
##Export File Format: Zip
# Once you click the export button ZoneMinder will go through the process of packaging and formatting the events for you, this process can be quite intensive for the server if a large number of events are selected. When the process is completed a download link for a file called zmExport.zip should pop up, select save file and click ok. It is important to make a note of where you save your file as you will need to access it later.

=Extracting Events=
A note about this section of the how to, For the examples i am using a custom export_functions.php plug-in that comes native in stagecoach wireless ZoneMinder installs.
Once you have selected your desired set of events you need a logical way to organize them and store them on your computer. My suggestion is too unzip all ZoneMinder exports to a specific folder so you have them all in one place to easily browse and backup.[http://www.gadgetsdotcom.com/ ]
==How to unpack the export files==
Most operating systems have many different applications that allow you to extract zoneminder.zip packages. For this example i will show you one way to do this.
===Linux===
[[image:archiveopen.png|right|thumb|caption|Ready to extract the events folder for viewing]]
#Navigate to the folder where zmexport.zip was downloaded to. In this example i have 4 zmexport.zip files extracted to the folder
#Double click opening up the archive manager
#Drag the events folder from the archive manager window into another folder. For ease of use i suggest you make a separate folder to store all your ZM export events in.
===Windows===
# Navigate to the folder where zmexport.zip was downloaded to. In this example i have 4 zmexport.zip files extracted to the folder
# Right-click the filename and select open with your archive manager (e.g 7-zip, winzip or winrar if you are using windows)
# When your archiving software is loaded up you should be able to select the events folder from zmexport.zip and drag it to your desired location in the file structure.

=Viewing Extracted Events=
[[image:zmeventsmasterfile.png|right|thumb|caption|zmEventImagesMaster.html has a time-stamp identifier so you can extract multiple events to one folder and still organize them by date]]
To view the events you have just extracted simply browse to the ''events'' folder. To view the interface of all events open up the newest zmEventImagesMaster file in Fire Fox.
From this page you get a tabbed view showing you events organized by monitor and chronological order. Within each events view you can display individual frames from the event or meta data about the event date/time/length
<gallery>
Image:zmeventmaster.png|Event viewer
Image:zmeventframes.png|Frames viewer
Image:zmeventdetails.png|Event data view
</gallery>
==Events folder structure==
*events
**monitor-ids
***event-ID
****zmEventDetail.html (this is the file that contains meta data about an individual event)
****zmEventFrames.html (this is the file containing a listed view of all event frames)
****xxx-capture.jpg (individual snapshot from the event)
**zmEventImagesMaster.html (this is the file that acts as the "home" page for each event extraction. you can extract multiple event sets to the events folder and acquire a list of these files

Troubleshooting

2011-04-08T11:45:39Z

Bs27975: /* General Troubleshooting */

==General Troubleshooting==
If you are having problems with ZoneMinder here are some things to try. If these don't work then check the ZoneMinder FAQ at http://www.zoneminder.com/wiki/index.php/FAQ and then the forums at http://www.zoneminder.com/forums.html first and see if anyone has had the same problem in the past. If not then feel free to get in touch and I'll see if I can suggest something else. Please ensure that you read the posting guidelines and go through the steps listed below before posting or mailing though.

The first thing you need to do is check the ZoneMinder logs to see if you can find out what is and what isn’t working. See the Logging section above for details about where the logs are and how to enable and control debug output, if required.

In general though, the best places to look for errors are in the system error log (normally /var/log/messages on RedHat), the ZoneMinder logs, and the web server log (/var/log/httpd/error_log unless otherwise defined). There should be something in one of those that gives you some kind of tip off.

Some other things you can check.

* Device configuration. If you can't get your cameras to work in ZoneMinder, firstly make sure that you have the correct settings. Use xawtv or something like that to check for settings that work and then run zmu -d <device> -q -v to get the settings. If you can't get them to work with that then the likelihood is they won't work with ZoneMinder. Also check the system logs (usually /var/log/messages) for any video configuration errors. If you get some and you're sure they're not a problem then switch off ZM_STRICT_VIDEO_CONFIG in zmconfig.pl or the ‘options’ tab.
* Start simple. Begin with a single monitor and single zone. You can run the zmc capture daemon from the command line as 'zmc --device <device>' (or whatever your video device is). If it returns immediately there's a problem so check the logs, if it stays up then your video configuration is probably ok. To get more information out of it use debug as specified below. Also check that the shared memory segment has been created by doing 'ipcs -m'. Finally, beware of doing tests as root and then trying to run as another user as some files may not be accessible. If you're checking things as root make sure that you clean up afterwards!
* Web server. Ensure that your web server can serve PHP files. It's also possible that your php.ini file may have some settings which break ZoneMinder, I'm not a PHP guru but setting safe mode may prevent your PHP files from running certain programs. You may have to set configuration to allow this. Also since the daemons are started by your web server, if it dies or is shut down then the daemons may disappear. In this version the daemons are run under the control of a script which should trap expected signals but it is possible this doesn't cover all circumstances. If everything else works but you can’t get images in your browser a likely cause is a mismatch between where your web server expects to execute CGI scripts and where you have installed the zms streaming server. Check your server configuration for the correct CGI location and ensure you have supplied the same directory to the ZoneMinder configure script via the --with-cgidir option.
* One of the more common errors you can see in the log files is of the form 'Can't shmget: Invalid argument'. Generally speaking this is caused by an attempt to allocate an amount of shared memory greater than your system can handle. The size it requests is base on the following formula, ring buffer size x image width x image height x 3 (for 24 bits images) + a bit of overhead. So if for instance you were using 24bit 640x480 then this would come to about 92Mb if you are using the default buffer size of 100. If this is too large then you can either reduce the image or buffer sizes or increase the maximum amount of shared memory available. If you are using RedHat then you can get details on how to change these settings at http://www.redhat.com/docs/manuals/database/RHDB-2.1-Manual/admin_user/kernel-resources.html.
* You should be able to use a similar procedure with other distributions to modify the shared memory pool without kernel recompilations though in some cases this may be necessary. You can also sometimes get shared memory errors if you have changed the monitor image size for instance. In this case it is sometimes that an old process is hanging onto the shared memory and will not let it be resized. Ensure that you do a full ZoneMinder restart and/or manually delete the shared memory segment to check. Use the ipcs and ipcrm system commands to check and remove segments if necessary.
* If you get odd javascript errors and your web console or other screens come up with bits missing then it's possible that there is a problem with the PHP configuration. Since version 0.9.8 ZoneMinder has used short PHP open tags to output information, so instead of something like this '<?php echo $value ?>', it will be something like this '<?= $value ?>' which is easier and quicker to write as well as being neater. More information about this directive can be seen at the following location, http://www.php.net/manual/en/configuration.directives.php#ini.short-open-tag. However although by default most PHP installations support this form, some will need to have it switched on explicitly. To do this you will first need to find your php.ini file (do a 'locate php.ini' or 'find / -name php.ini'. Be aware however that sometimes you might find more than one, so ensure you identify the one that is actually being used. You will then need to find the line that starts 'short_open_tag = ' and change the Off value to On. This will correct the problem. However in some cases you may have explicitly switched it off, so that XML compliant documents can be more easily served, or you may even not have permission to edit the file. In this case you can go into the web directory of ZoneMinder and run 'sh retag.sh' which will replace all the short open tags in the files themselves with the longer variant. You will obviously have to remember to do this for each subsequent version of ZoneMinder that you install as well.
* Paths. I admit it, the various paths in ZoneMinder can be a little hard to work out mainly because some relate to real directories and others to web paths. Make sure that they are all sensible and correct and that permissions are such that the various parts of ZoneMinder can actually run.
* Missing perl modules. There are various perl modules used by the various scripts. The configure script should inform you if a required or optional module is absent but it is possible some may get missed. If you get errors about missing modules, the easiest way to install them is via 'yum' or your distributions package manager. In Fedora for example to install module XXX:YYY is to type '''yum install perl-XXX-YYY'''. The alternative, if the module is not available via that route or your prefer to build from source, is to type the following (you will probably need to be root), '''perl -MCPAN -eshell''' this will then (eventually, after some configuration if it’s your first time) present you with a prompt. From there you can type install module, e.g. Archive::Zip and the rest should be more or less automatic as it will chase any dependencies for you. There may be some initial configuration questions it might ask you on startup if you've never run it before and to speed things up I would not install a new Bundle at this point (it can end up building you a whole new perl if you’re not careful) if it asks you but everything else should be quite straightforward. You can often also install perl modules via your ordinary package manager, e.g. yum or apt.
* Unsupported palettes. ZoneMinder currently is designed to use the simple palettes of greyscale and 24 bit as well as now the YUV420P and some other palettes. This should cover most cameras but it's possible that there are ones out there that might want to use more esoteric formats that ZoneMinder doesn’t support. This will often show up as the capture daemon being unable to set picture attributes. If this occurs try using different palettes starting with greyscale and if you can't get anything to work let me know and I'll try and add it.
* USB bus problems. If you have multiple USB cameras on one bus then it can appear as if ZoneMinder is causing your cameras to fail. This is because the bandwidth available to cameras is limited by the fairly low USB speed. In order to use more than one USB camera with ZoneMinder (or any application) you will need to inform the driver that there are other cameras requiring bandwidth. This is usually done with a simple module option. Examples are usb_alt=<n> for the OV511 driver and cams=<n> for CPIA etc. Check your driver documentation for more details. Be aware however that sharing cameras in this way on one bus will also limit the capture rate due to the reduced bandwidth.
* Incorrect libjpeg.a detection. It seems to be the case that in some cases the library file libjpeg.a is reported as missing even when apparently present. This appears to actually be down to the g++ compiler not being installed on the host system. Since ZoneMinder contains both C++ and C files you need to be able to compile both of these file types and so usually need to ensure you have gcc and g++ installed (though they are often the same binary).
* Httpd and zms memory leaks. It has been reported by some users with RedHat 9 that the zms process fails to terminate correctly when the controlled window is killed and also that it, and it’s associated httpd process, continue to grow in memory size until they kill the system. This appears to be a bug in early versions of apache 2. On other systems it may appear that zms is leaking and growing. However what grows is the total and shared memory size while the non-shared memory size stays constant. It's a little odd but I think what it happening is that as zms picks images out of the shared memory ring buffer to display, as each slot is read the size of that bit of memory is added to the shared memory total for the process. As streamed images are not read consecutively it's a semi-random process so initially most of the buffer slots are new and the shared memory size grows then as time goes on the remaining unaccessed slots reduce until once all have been read the shared memory use caps out at the same size as the actual segment. This is what I would have expected it to be in the first place, but it seems to do it incrementally. Then once this total is hit it grows no further. As it's shared memory anyway and already in use this apparent leak is not consuming any more memory than when it started.

Also, if you are using IE under Windows and get lots of annoying clicks when various windows refresh then you'll need to edit your registry and remove the value for HKEY_CURRENT_USER\AppEvents\Schemes\Apps\Explorer\Navigating\.current or download the registry script to do it for you from http://www.zoneminder.com/downloads/noIEClick.reg

==Missing/No video or monitor shows RED in ZM Console==
*First and most importantly TRY accessing the camera stream using FFMPEG/mplayer/xawtv and make sure you can access the video stream that way, as frequently if it won't work there its easier to troubleshoot it with those applications than with ZM. If you do get it working with FFMPEG there is almost no reason it shouldn't work in ZM. Note if your camera is putting out a mjpeg stream then FFMPEG/mplayer require the file to end in .mjpg or .mjpeg for remote urls this can be accomplished by appending ?a=.mjpg to the stream so if your camera url is: http://123.123.123.123/stream.cgi you would turn this into: http://123.123.123.123/stream.cgi?a=.mjpg if your stream already has a query string on it (a ? ) then just do &a=.mjpg at the end of it.
**If you did get it working using mplayer/ffmpeg and are using a "Source Type" other than FFMPEG in zoneminder try using FFMPEG. FFMPEG is frequently more tolerant of issues than some of the native ZM camera support (just make sure you have ZM compiled with FFMPEG support, and if possible use the newest version of FFMPEG that you can).
*If your specific camera is talked about either on the wiki or in the supported hardware on the forums look at exactly what people did to make it work.
*Make sure the Monitor Function is obviously not set to "None" for the monitor or ZM will not touch it.
*Ensure zoneminder is setup for extra debugging so go to the Options in the web console then the debug tab:
**Switch additional debugging on(EXTRA_DEBUG)
**Set debug level to 5 (EXTRA_DEBUG_LEVEL)
**Make sure The debug output location is valid the default of /tmp/zm_debug.log+ is generally fine (EXTRA_DEBUG_LOG)
**Make sure the general log path (Under Path's tab) is valid(PATH_LOGS)
**Save changes and Restart zoneminder so changes take effect.
*Now make note of the monitor ID you want to debug (if you are not sure click it under the Source column and in the popup window it will say: Monitor - WhateverMonitorName (1234) where 1234 will be the monitor ID
*Now you will want to check two sets of logs, first are the generally logs which for zone minder will be in the folder PATH_LOGS and also in your syslog. You may find it easier to filter the zoneminder messages out of your default syslog file (but that is beyond this scope) if you have not filtered them out they will most likely be in /var/log/messages (or whatever your default log file is). It can be helpful to stop zone minder, erase them, and then start zone minder so you can look at each one and see exactly what happened as ZM started up.
*Finally/Most usefully you will want to check the individual log file for the exact zone minder capture daemon for that monitor (zoneminder should be running). To find this log file from a shell run "ps axf | grep zmc" it should show you one or more zmc processes. After each one will be a "-m 1234" where 1234 is the monitor it is capturing for. You will also notice on the far left side of the output of that line will be a number, this is the PID of the process. If you do not see any zmc processes running most likely they are crashing after they start. To figure out the crashed zmc's PID so you can look as its log you want to check the zmdc.log file, it will say something like "zmdc[6001].INF ['zmc -m 1234' starting at 1/1/1 02:56:25, pid = 459]" so you can get its PID from there. Now the ZM log file for the process will be at EXTRA_DEBUG_LOG + .PID however the PID is padded out to 5 chars (with 0's at the front) So if your EXTRA_DEBUG_LOG is: "/tmp/zm_debug.log+" and the PID is 459 of the ZMC process then the log file would be /tmp/zm_debug.log.00459 This file will most likely have the gold that you are looking for as to what is going on/wrong.
*Of course if ZMC shows no errors and seems to be going fine, it may make sense to look at the ZMA daemon it is the next its the next step.

==Getting FREE help from others==
There are two main places you can ask for help, the forums and IRC (irc.freenode.net #zoneminder) BEFORE you ask for help please make sure you read ALL of the Documentation and all of this troubleshooting page. Also see: http://www.zoneminder.com/forums/viewtopic.php?t=12385 . Search for problems like yours on the forums. Please try and upgrade to the latest version of zoneminder if you can, as many bugs get fixed and we generally prefer to debug issues on the current version. If you still need assistance its time to do so correctly. Make sure you are very specific on whats going on, what you have done to try and troubleshoot it, and use http://pastebin.com/ to post output from logs related to your issue (try to only post the related parts). Make sure you are very specific and give as much details as possible. If you ask very generic questions or it doesn't seem you have tried what is recommended you may not get responses.

==Getting PAID suppport==
If you are willing to pay for support still try the forums or IRC if you have the time/ability may help you find someone who can help you anyway, but otherwise email support at zoneminder dot com and mention you are looking for paid support. We should be able to have someone get in contact with you shortly and help you. It is still recommended you do the above things as it will help us speed up helping you which means it will also cost you less and get you running faster.

Talk:Main Documentation

2011-04-06T02:15:03Z

Bs27975: /* Tutorial */ new section