In order to be able to view videos and audio, you may need some plugins available for free on the Internet (maybe they could be already installed on your computer).
Each stream could require a different plugin and you are able to don't have all these plugin installed (even if missing plugins could cause to don't be able to see a stream).
The plugin needed to view each stream is briefly mentioned in the description window. Some special channeld may require plugins not listed here.
You can try to autodetect plugin and other common configuration problems using our
automatic test.