There are a number of ways to stream video to your audience. Got a film under 15 minutes and want it to be public then it is very hard to go past Youtube as the site is popular and hosting is free. What if your video is longer than 15 minutes and it's all your own work well then you can choose between Vimeo or Viddler  which are also free but the material must not be for commercial gain. There have been stories of companies on Vimeo  having their videos removed because they were commercial. Vimeo has a paid service for less and $100 a year and while this gives more functionality it still mustn't be commercial videos.

Podcasting is a method of publishing audio and video content via the Internet allowing users to subscribe to a feed and to receive new content automatically.  As new material is place on the feeder site your podcasting software will detect it and you can elect to automatically download it or selectively choose. The question is how to do this in Joomla.