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Black Screen Always...

Posted: Thu May 08, 2008 4:52 pm
by Socom
I am running Ubuntu 8.04 and Zone Minder v1.23.3. Logitech Communicate STX.

I am trying to setup the system with web cams for now. I have one cam in to test. Using Ekiga I can see the video the camera puts out. Works fine there as I had it detect the camera.

In Zone Minder I have it set the same. My source shows green, which I assume means it is working with the camera, however whenever I open it up, all I get is a black screen where the video should be.

I checked the /var/log/messages and I have a few lines that I am confused about that could be part of the problem, though I am unsure what to do. They are:

May 8 12:05:00 media zmdc[17673]: INF ['zma -m 5' started at 08/05/08 12:05:00]
May 8 12:05:00 media zma_m5[17673]: INF [Debug Level = 0, Debug Log = <none>]
May 8 12:05:00 media zmdc[29964]: INF [Can't find child with pid of '17673']
May 8 12:05:00 media zmdc[29964]: INF ['zma -m 5' starting at 08/05/08 12:05:00, pid = 17673]
May 8 12:05:06 media zmwatch[29991]: INF [Restarting capture daemon for Front, shared memory not valid]
May 8 12:05:06 media zmdc[29964]: INF ['zmc -d /dev/video' stopping at 08/05/08 12:05:06]
May 8 12:05:06 media zmwatch[29991]: INF ['zmc -d /dev/video' stopping at 08/05/08 12:05:06]

Can anyone help me with this please... thanks!

Posted: Thu May 08, 2008 5:04 pm
by Lee Sharp
Ekiga can use v4l2 and ZoneMinder uses v4l1 only. I do not know if your camera has v4l1 support.

Posted: Thu May 08, 2008 5:07 pm
by Socom
In Ekiga it is set to V4L, not V4L2, so I assume I should be good that way.

Posted: Fri May 09, 2008 9:57 pm
by PeterHoward
The log messages are saying that the capture daemon isn't starting up properly. Can you manually change the permissions on /dev/video* to 777? (i.e. "sudo chmod 777 /dev/video0"), then restart zoneminder ("/etc/init.d zoneminder restart")

The restart bit assumes you installed from the package. If you installed from source then stop and start it from the front page.

PJH

Posted: Sat May 10, 2008 2:29 pm
by Socom
Ok, did the chmod and restarted, same black screen, but what looks like new errors in the Messages log...

May 10 10:26:12 media zmc_dvideo[29967]: INF [Debug Level = 0, Debug Log = <none>]
May 10 10:26:12 media zmdc[29921]: INF [Can't find child with pid of '29967']
May 10 10:26:12 media zmdc[29921]: INF ['zmc -d /dev/video' starting at 08/05/10 10:26:12, pid = 29967]
May 10 10:26:12 media zmwatch[29952]: INF [Can't find child with pid of '29967']
May 10 10:26:22 media zmwatch[29952]: INF [Restarting capture daemon for Front, shared memory not valid]
May 10 10:26:22 media zmdc[29921]: INF ['zmc -d /dev/video' stopping at 08/05/10 10:26:22]
May 10 10:26:22 media zmwatch[29952]: INF ['zmc -d /dev/video' stopping at 08/05/10 10:26:22]
May 10 10:26:32 media zmwatch[29952]: INF [Restarting capture daemon for Front, shared memory not valid]
May 10 10:26:32 media zmdc[29971]: INF ['zmc -d /dev/video' started at 08/05/10 10:26:32]
May 10 10:26:32 media zmc_dvideo[29971]: INF [Debug Level = 0, Debug Log = <none>]

Posted: Sun May 11, 2008 3:05 am
by gasmasher
I have a feeling you are running into the same problem I am with the kernel version. I am using the recent 2.6.25. Can you check which version you are running?

Code: Select all

uname -r
I think this has something to do with the removal of the old v4l interface in the latest kernels. If I understand things properly it is now only accessible through the v4l2 to v4l compatibility layer and that appears to be buggy.

My PV-981 capture card (bt878 chipset) has the same problem. When I use the v4l2 driver it works great but switching to the v4l driver causes the sleep state problem and I have the compatibility layer compiled into my kernel. I can replicate this with mplayer time and again. Check the wait state of the zmc process with ps and I bet it says D.

Code: Select all

ps ax -o pid,state,command | grep zmc
I don't know what the solution is since I am not a very experienced C++/PERL programmer (any chance we can have a port of ZM to object pascal? ;) ). One way might be to downgrade kernels to get the old interface back, but that will probably cause other problems with Ubuntu. Unfortunately I can't try that since the drivers for the chipset on my motherboard weren't introduced until after the v4l removal.

Posted: Mon May 12, 2008 2:54 pm
by Socom
Ok, I am running 2.3.24-16-server

when I do your other command I get...

20860 R grep zmc

however when I run the app under sudo I get...

20883 S grep zmc

honestly no idea what I am looking at and feel I am not getting the result you wanted me to :)

Hope this tells you something other then I dont know what I am doing!

Thanks again.

Posted: Wed May 14, 2008 4:14 am
by gasmasher
Sorry Socom, but it seems you don't have the same problem I did. I am assuming that you made a typo on the kernel version and meant 2.6.24-16 instead of 2.3.24. The v4l compatibility layer problems I mentioned above don't exist in 2.6.24 as long as you still have video for linux 1 compiled into the kernel.

Posted: Thu May 15, 2008 2:29 pm
by Socom
hm, ya, video works, the camera displays correctly on other software, just not ZM, does anyone else have any ideas?

Posted: Fri May 16, 2008 5:25 pm
by Hatchet
I have the same problem with my Kworld BTTV card. It seems to have the wrong card number and type settings. Although it works with TVtime like it should. My other Winfast 2000XP card works fine with ZM 1.23.3.

I am using Fedora 9 - Kernel 2.6.25.3-18.fc9.x86_64. Is there a way to change the capture card settings? I tried modprobe.conf with no effect. So now I am trying to find another way to force the card settings so that ZM will see it properly.

BTW, I was getting the error: Shared memory not initialised by capture daemon. This is with my BT878 Kworld card.

Posted: Sun May 18, 2008 1:14 pm
by Hatchet
OK, I found that this seems to be a v4l v4l2 problem (like mentioned in previous messages) with the new kernels and BTTV cards. I haven't found a fix so far.


(update)This is another mention of the problem.

http://www.zoneminder.com/forums/viewto ... 878+kworld