Many video src pads from one element

[Josh Doe]

I've created an element which interfaces with a library that produces
an arbitrary number of video streams. I started by subclassing
GstPushSrc to just push out one stream, but now I'd like it to support
multiple streams, so I have to go back to GstElement. I get a callback
as each frame is rendered by the library (the library is single
threaded), so I need to copy this frame, then signal another thread to
do some minimal format processing and push the buffer on the pad.

Am I right in thinking that I'll want to start a task on each
sometimes pad I create, which will use a GCond to wait for a new frame
to be available?

Are there any existing elements that would be helpful for me to look at?

Thanks,
-Josh