That’s strange: it really doesn’t work on my end. (I put audio/mpeg for the mime type, and object.item.audioItem as the Upnp class). This creates a file the WDTV Live tries but fail to play. Then, I get the same result as when URLs are embedded in a standard playlist: the spinning waiting animation of death, as described in this thread.
Do you use the most recent non-bricking firmware (1.01.11)? Are you able to simply play streams embedded in m3u or pls playlist files? I wonder what is wrong with my setup…
