Accessing a hardware node from two different software at the same time

Hello;

How can i access a device node from different softwares at the same time. e.g. i have a capture card with 8 ports and i want to access my /dev/video0 from mplayer by 8 different inputs ( i mean cameras ). But after first access to the first camera /dev/video0 is locked and i cannot access /dev/video0 again. mplayer says the resource is busy.

how can i solve this problem and use 8 cameras for video capture at the same time by accessing /dev/video0 from different inputs.

thanks for your replies.

Please help me dear friends i have to solve this problem as soon as possible. it is quite interestin that nobody knows about this situation :(