Appendix A: An Introduction to Streaming Media
132 ViewCast
you “hire” a CDN to deliver your content. Some CDN companies have online account signup so
you can create an instant relationship and be streaming globally in mere minutes.
How viewers find the stream
So far, you are capturing and encoding live video and audio and creating a TCP/IP stream. You
have signed up a CDN, and now you want your audience to view it.
So, what’s next? You will need some way for your audience to know how, and where, to pick up
your stream for viewing.
Here’s how that typically works: when you sign up with a streaming service provider (CDN), they
will give you both a network address to send your Uplink video to (their server network’s input
point), and a link to the server output. The Output URL is important because it is where you
want your viewer to browse. For browser-based users the publish link is usually contained in a
website link (Step 2); clicking on the link (Step 3) launches an appropriate video player (if one is
installed on the viewer’s computer) and the playback experience begins. For mobile devices and
most TV-based playback applications, the link is contained in some sort of electronic program
guide. The guide can be searchable and even schedule-able. When the link is selected, a suitable
player is launched and the video appears on-screen. You can also send the links in e-mails or
include them in electronic newsletters. The reader then simply clicks the link to watch the video
on their computer or mobile device.
Are we on the air?
Almost. Once your viewers have an active URL, clicking on it will usually launch a compatible
video player. But, as we noted earlier, not every playback device can play every type of video
stream. Most players will invite the user to allow automatic installation of the components
needed to view the stream type, but not always. To ensure that anyone can view your stream,
you may want to stream in more than one format at the same time. Niagara streaming encoders
from ViewCast include everything you need to stream in multiple formats, simultaneously. In
practice, each different stream from the Encoder would be fed to the Server or server array, and
multiple URLs (one for each stream type) would be offered to the viewer. Then the viewer need
only click on his or her preference to receive the proper stream.
