Need some help!

Hi, all,

         I  still do not understand Video4linux approach very well, so I
want
some one give me some explain about the Video4linux.

         Why we need the video4linux approach? Why we did not just directly
write the driver? or in other word, what is the benifit using video4linux
approach?

        Except for the video4linux approach, if there are still other ways
to write
a driver for a video capture card ?(For I am developing such a driver.)


        Thank you very much!

yencha