Hitchhiker's Guide to Streaming Media: Webcasting
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About eight years after Ford Prefect (the former guide reporter from Planet Earth) thumbed an unscheduled lift from a passing Vogon Constructor fleet, Daniel Keys Moran used the term “webcast” in a book called
to describe a news bulletin that featured in the story.
The distribution of live and recorded video and audio using the internet for distribution and web pages for presentation. webcasts range from small tutorials to global entertainment events. Generally they are a one-way video and audio transmission, but often include interactive systems to enable the audience to feedback to the speakers (for example with questions and answers).
Some of the earliest non-fictional webcasts were first seen in the early half of the last ten years of the second millennium. Steve Mack is widely understood to have deployed the first public webcast from the U.S. in 1995 (a webcast of a Seattle Mariners baseball game) and the first webcast in the Europe was provisioned by Gavin Starks in the UK in 1996.
Professional webcasters (including the author) have been providing services to the market since 1995/96, and the market has grown explosively since that time.
Usually webcasts are considered to be individual “events” rather than “simulcasts” of 24/7 TV and radio, although the technology and service delivery is generally the same. Webcasting often adds in the complexity of provisioning broadcast type technologies at the event itself, and so introduce the complexity of connectivity from the event to the internet. This is typically achieved in two ways:
1) Where the event is already being broadcast, or there are few specific requirements for extra functionality such as interactivity, a traditional broadcast satellite (or other) feed is often encoded at the “downlink” and delivered from there, via a permanent IP connection, to the Content Distribution Network for onward distribution to the end users.
2) Where the event has requirements for the field engineers to have internet connectivity provided right to the event, several options are available. Ultimately one of the key problems is that telecoms have to be installed to provide high quality internet access for the encoder to deliver a good source feed to the CDN. One option that is becoming more commonplace is the provision of satellite internet services. This allows ad-hoc connectivity to be provided as required. Once this is in place the encoders can be located in the field and the source can be delivered direct to the CDN.
The key advantage of this second method is lower cost. Internet video is more compressed than broadcast video. This means it is cheaper to use internet satellite services than broadcast satellite (both of which charge by bandwidth and time).
Some of the largest webcasts with published results claim 170,000+ simultaneous viewers/listeners. Statistics such as this are often produced by the webcasters themselves, so figures vary considerably and are difficult to validate. There have been moves across the industry, in particular from the International Webcasters Associations in the U.S. and Europe, to attempt to bring some external validation to this, and often advertisers will introduce their own metrics.
Webcasts have so far also provided a means for broadcasters to operate outside of their normal broadcast licenses, although worldwide regulators are constantly reviewing legislation. This often means that webcasters are at the forefront of regulatory advice and consultations.
Don’t panic. Next time: The Hitchhiker’s Guide to Encoding