To get Real Media content (RM/RA/RV) to play within Zoom Player (or any other DirectShow based player), you will need
the Gabest RealMedia Splitter filter.
You will also need to make sure that the latest version of the Real player is installed so that all the RealMedia codecs
are installed with it. This filter doesn't decode the RealMedia content, it's just a bridge between DirectShow and the
RealMedia decoders.
As an alternative to installing Real Player, you can instead install Real Alternative. Real Alternative is a community
made collection of all the RealMedia codecs, without the player. Real Alternative does not seem to have an official web
page, but searching for "Real Alternative" in any web search engine should yield instant results.