What device or client are you trying to publish to?
Looking at the
HbbTV Wikipedia article it seems that the platform can handle many inputs. You might be able to use the
PushPublish addon to publish a stream that it can use. If it has a playback clients, you might be able to playback streams from Wowza. It's not clear what platform provides at the level. I would think you could at least publish to it, but not sure.