Hello everyone I'm a newbie here and wanted to setup a PC based surveillance system. I read that ZM supports multiple camera and was wondering how that works. I wanted to connect two or more usb webcam onto one PC to monitor different views. So if your PC has two or more USB ports are you able to stream two camera view? Will that create any driver issues? Or do I need some other USB switch hardware? If anyone here has configured their PC with multiple cam please let me know what you did to set it up. Thank you for your help
Ken
Setting up Multiple Cam on One PC
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tech_fixer
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Re: Setting up Multiple Cam on One PC
Kenneth,
When you plug multiple USB cameras to a Linux box, that are supported by V4L (Video 4 Linux) they get assigned a device name under the /dev directory. Usually it is /dev/videoX, substituting the X for a number from 0 to as much as your machine can take.
This assignment is made on a first come first served basis. So if your machine is on, and you plug many cameras to it, the first camera will be video0, the second will be video1, and so on.
Now, it gets trickier when you turn your machine with all cameras hooked up. The OS will assign a videoX device name to each camera, but which is which? Well, as long as you dont change the cameras around from USB port to USB port, the assignment stays pretty much the same. So you could use a program like xawtv to find out which camera is hooked up to a videoX device name. Just do "xawtv -c /dev/videoX", changing the X for an appropiate number, and you should get that camera's image on your screen.
The Readme file included with ZoneMinder, which you can view separately in the download section, describes how to setup multiple cameras under the videoX scheme.
If this is too much guesswork, then you can buy one multiple-channel video grabber card. These retain their device names in a more permanent manner. Other fellows here in the forums seem to be working ok with such cards.
Regards,
Jose Rodriguez
When you plug multiple USB cameras to a Linux box, that are supported by V4L (Video 4 Linux) they get assigned a device name under the /dev directory. Usually it is /dev/videoX, substituting the X for a number from 0 to as much as your machine can take.
This assignment is made on a first come first served basis. So if your machine is on, and you plug many cameras to it, the first camera will be video0, the second will be video1, and so on.
Now, it gets trickier when you turn your machine with all cameras hooked up. The OS will assign a videoX device name to each camera, but which is which? Well, as long as you dont change the cameras around from USB port to USB port, the assignment stays pretty much the same. So you could use a program like xawtv to find out which camera is hooked up to a videoX device name. Just do "xawtv -c /dev/videoX", changing the X for an appropiate number, and you should get that camera's image on your screen.
The Readme file included with ZoneMinder, which you can view separately in the download section, describes how to setup multiple cameras under the videoX scheme.
If this is too much guesswork, then you can buy one multiple-channel video grabber card. These retain their device names in a more permanent manner. Other fellows here in the forums seem to be working ok with such cards.
Regards,
Jose Rodriguez
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Re: Setting up Multiple Cam on One PC
Hi Kenneth,
The other thing you need to be aware of when using multiple cameras on one USB bus is that of bandwidth contention. Normally a camera driver when loaded will assume it can use all of the bandwidth, however when you have two or more cameras with the same assumption this will cause problems. You need to check your camera driver and ensure you have set the appropriate options to inform your camera drivers that they are sharing the bus, see the README for details.
Cheers,
Phil,
The other thing you need to be aware of when using multiple cameras on one USB bus is that of bandwidth contention. Normally a camera driver when loaded will assume it can use all of the bandwidth, however when you have two or more cameras with the same assumption this will cause problems. You need to check your camera driver and ensure you have set the appropriate options to inform your camera drivers that they are sharing the bus, see the README for details.
Cheers,
Phil,