Linux Media Labs LMLBT44

From ZoneMinder Wiki
Jump to: navigation, search

I am curious why this page is blank, commented on further on the discussion page.

To help fill the void, I will try to contribute with some of my experience with this card. LMLBT44

I was able to order the LML card from Linux media labs, and I received a working card, and a single printed sheet that directed me to their website for documentation. I also got a daughter card, which was old and dusty and used, and a short cable that is missing the "red cable" "pin one" they mention in the docs. Also missing is the ZM-Live CD-Rom which is promised in the docs.

The documentation on the website is extremely sparse and very out of date. You need to know a bit about loading kernel modules to figure out how to set up this card under any modern (2.6 and up) version of Linux. The V4L kernel modules are included in the standard Linux distribution for 2.6 and up, so that is covered. But the configuration of modules changed, and the docs do nothing to help the novice.

So, based on my sketchy memory, here is the skinny:

Make sure that in the file /etc/modprobe.d/aliases, there is a line:

alias char-major-81-0 bttv

This corresponds to one of the entries the docs say should be in modules.conf (which is depreciated).

I added a file /etc/modprobe.d/lml-bttv with the following additional lines:

alias char-major-81-64 bttv

options bttv card=118,118,118,118

I do not know how to modify the udev conf files to get the devices created automatically, so I just added the following lines to my zoneminder startup script:

       if [ ! -r /dev/video4 ]
       then
               mknod /dev/video4 c 81 4
       fi
       if [ ! -r /dev/video5 ]
       then
               mknod /dev/video5 c 81 5
       fi
       if [ ! -r /dev/video6 ]
       then
               mknod /dev/video6 c 81 6
       fi
       if [ ! -r /dev/video7 ]
       then
               mknod /dev/video7 c 81 7
       fi
       chgrp video /dev/video?

I also found it necessary (easiest?) to change the perms on all the video devs to 777:

       chmod a+rw /dev/video*

And now I have working video on channels 0 to 3.

Unfortunately, the header pins on the main board for the connector cable has more pins than the connector, so I am not sure exactly where to plug in the cable. Also, because the cable is missing the pin 1 designator anywhere, I am not sure if I have the cable reversed. AND, the diagram of the cards and cables in the docs is reduced so that all of the text is unreadable. I am unable to get the video working on channels 4 to 7. I don't know if it is the cable that is plugged in wrong, or the modules config or something else that is deficient. The docs are no help whatsoever. A search of Google turns up very little help either.

Finally, the zoneminder config for the board includes setting sourcetype to "local", device path to "/dev/video0" (or 1,2,3) and Device Channel to zero.

In summary, the board works great. If you don't mind reading up on modprobe and mknod and using alot of trial and error, it works fine. I cannot give LML a satisfactory rating because they sent me an old used daughterboard, old funky docs and no CD-Rom. Unless you know alot about Linux (including kernel modules), you are going to likely have a very tough time getting this board to work. The working ZM-Live CD would have been a huge help, because at least I could have got a working system to see what all the config settings are.. I wish I could get the second set of inputs to work, and I would suppose a working Live CD would help me there.

I hope this helps somebody. I sure would have appreciated knowing this before I bought the board.