capture using v4l2 and display preview using gstreamer

How to pass the buffer/userpointer to gstreamer after Q_BUF, STREAM_ON, DQ_BUF.

I tried using PIL's method frombuffer, but with no suc开发者_JS百科cess. so I want to use gst sink now.

Should I use gst.parse_launch() and how?

Have anybody done it?

The source code to Cheese tells all. http://projects.gnome.org/cheese/