is it possible to change volume filter in runtime?

[dibalavs]

google sayd that ffmpeg uses azmq to change filter options at runtime.
I am trying to use it for volume filter.

links.append(self._graph.add("volume@my","azmq"))
links.append(self._graph.add("volume", "42,azmq"))
links.append(self._graph.add("volume", "azmq"))

but I receive an error. about error in filter value.
How to use zmq in pyav? Or another way to change volume filter option at runtime