3 Identical Cameras, Only one shows video: SOLVED

[Eric0321]

I have ZM up and running but it will only pull video from one of my three cameras. They are all the same model, DCS-932L, and each camera has identical settings on the camera and within ZM other than the IP address. I verified that all three cameras are working and producing an image by going to their corresponding jpeg.cgi URL (which is the host name and path I am using under each monitor's settings):


http://192.168.1.50/image/jpeg.cgi
http://192.168.1.51/image/jpeg.cgi
http://192.168.1.52/image/jpeg.cgi

All three show images and refresh correctly when I browse them directly. ZM will only consume from http://192.168.1.50/image/jpeg.cgi The other three monitors show up as red under the Source column and will not display the video from 192.168.1.51 and 192.168.1.52. Any ideas why it would do that? I also created a cameras.html file that shows each jpeg.cgi feed above, it works for all three cameras.

Any help appreciated.

[Eric0321]

Very odd development...
If I change the pixels for the width and height for each camera ZM will then see all of them, not ideal obviously as I'd like to use 640x480 for all.

So:
Monitor-1 is 640x480
Monitor-2 is 320x240
Monitor-3 is 160x120

If I change them all back to being 640x480 only Monitor-1 can be viewed from ZM again... This doesn't make any sense to me.

[marco123]

i have 2 cam ...
1) edimax
2) DCS-931
my remote host name is : admin:1234@192.168.1.133 / 134 (login & password are admin:1234 )
my remote host port are 8081 ... 8080 ...

931.jpg (41.93 KiB) Viewed 14374 times

edimax.jpg (41.34 KiB) Viewed 14374 times

[PacoLM]

Check your memory, maybe you do not have enough memory to support your 3 cams using the same resolution, so when you lower it, you are able to see the image.

[Eric0321]

Thanks for the above suggestions.

-Authentication for Snapshot Viewing is disabled on each camera so I don't need to put the user:pass@IPADDRESS, verified working by directly viewing the jpeg.cgi stream from a web browser.

-I tried changing the port of 192.168.1.51 to 81 but it still would not be seen by ZM

-The server I am running ZM on has 64GB of RAM with 2x Xeon E5-2660 CPUs. Though it is running inside of a docker container https://hub.docker.com/r/aptalca/zoneminder-1.29/ I'll check to see how much memory is being allocated within the container. I couldn't imagine that three streams of 640x480 would be a problem for it but worth checking. -UPDATE- The memory from the server appears to pass through to the container, memory isn't a problem.

So far the only thing that I can change for ZM to see all three is change the pixel dimensions to be different for each camera.

[mikb]

Try: Change the FIRST one to 160x -- the 2nd to 320x and the third to 640x480 -- and restart ZM -- which one works *now*?

Could be the order of start up will allow only the first camera?

Could be a memory issue if you now get camera 1 and 2, but not 3 ... if you see what I mean!

Or Try: set them all to 160x and see if they work better, temporarily, and for fault finding only

What changes? What stays the same?

[Eric0321]

Swapping Monitor-1 and Monitor-2 so that 1 is 160x120 and 2 is 640x480 allows 2 and 1 to be seen by ZM, 3 is still at 640x480 and isn't seen. So it appears that whichever camera is setup as 640x480 first is seen. If I set the others to different resolutions it will see them.

Setting all cameras to 160x120 allows ZM to see them all. So perhaps it is indeed a memory issue, which I don't understand because it has oodles available to it. Maybe there is a setting actually limiting the container's memory? When I open a bash shell from within the container it gives the same memory available as outside of the container, which I would assume means that it has that much memory available inside the container.

320x340 is working for all now too. Weird... I tried setting two of them at 320x240 last night with no luck. I'll try 640x480 again.

[Eric0321]

Tried to set Monitor-3 back to 640x480 and it does not work, 2 and 1 were still at 320x240 and work

Changed all back to 640x480 and only 1 works. Infuriating

[Eric0321]

Here is what the log is saying for Monitor-1 and Monitor-2

zmc_m3 1767 ERR Unable to decode jpeg zm_remote_camera_http.cpp 1151
zmc_m3 1767 ERR Failed requesting writeable buffer for reading JPEG image. zm_image.cpp 1051
zmc_m3 1767 ERR Held buffer is undersized for requested buffer zm_image.cpp 331

The buffer settings for each monitor are identical. It's sounding more like a memory issue, but the container appears to have full access to the 64GB of RAM so I find that confusing.

This is only when I use 640x480. I can get 320x240 working for all cameras. Want 640x480 for obvious reasons...

[Eric0321]

Another Development:
If I reduce the Image Buffer Size (frames) setting for each camera to 25 down from 50 I can see two cameras at 640x480 now. So it is a shared memory problem. I now need to figure out how to increase this within the docker container or whether increasing it for the host OS accomplishes that.

Host OS is Ubuntu 16.04.1 LTS x86_64 Server

UPDATE:

All three cameras work now with the below settings:


I want to increase the shared memory so that I can put the settings back up to default. I'm not sure how to do that yet. I have more that sufficient RAM to handle this. Not sure why it would be set so low by default.

[Eric0321]

Here are my current share memory settings:

user@server:/etc/sysctl.d$ cat /proc/sys/kernel/shmmax
18446744073692774399

user@server:/etc/sysctl.d$ cat /proc/sys/kernel/shmall
18446744073692774399

user@server:/etc/sysctl.d$ ipcs -l

------ Messages Limits --------
max queues system wide = 32000
max size of message (bytes) = 8192
default max size of queue (bytes) = 16384

------ Shared Memory Limits --------
max number of segments = 4096
max seg size (kbytes) = 18014398509465599
max total shared memory (kbytes) = 18014398442373116
min seg size (bytes) = 1

------ Semaphore Limits --------
max number of arrays = 32000
max semaphores per array = 32000
max semaphores system wide = 1024000000
max ops per semop call = 500
semaphore max value = 32767

I'm not yet sure how to modify it or what to modify it to. I read that these settings are passed to the docker containers so modifying it on the host OS should be fine.

[Eric0321]

Solved!

The /dev/shm mount within the container was only 14MB and was insufficient to handle the three cameras @ 640x480.

I passed the host OS's /dev/shm in as a volume instead of using the container's /dev/shm and it fixed it.

Thanks for the assistance!

[PacoLM]

Congratulations!

[Eric0321]

Thanks. I had a difficult time understanding how memory could have been the issue with so much RAM available. Now that I know what the problem was it makes sense with the way shared memory and/or Mmap mapped memory is utilized.

[spyderdyne]

No video at all on 1.30.4. Only stills. CGI fix doesnt seem to help. Also chmod 777 on /var/lib/zoneminder/cgi-bin/zms doesnt fix so probably not a perms issue with the nph-zms symlink. More details here:

<url>https://github.com/aptalca/docker-zonem ... es/14</url>

Camera setup here:

<url>viewtopic.php?t=26190</url>

1.30.4 also seems to break HTTP auth support, at least on AXIS IP cams.

UPDATE>>>

root@ayana-angel:~# df -m /var/lib/lxd/devices/zoneminder/disk.dev-shm/
Filesystem 1M-blocks Used Available Use% Mounted on
tmpfs 8008 199 7809 3% /var/lib/lxd/devices/zoneminder/disk.dev-shm
root@ayana-angel:~# df -m /dev/shm
Filesystem 1M-blocks Used Available Use% Mounted on
tmpfs 8008 199 7809 3% /dev/shm

mapping the container SHM to the host SHM did not change the behavior.