Delivering Media - the Technical Side

There are two ways to deliver audio over the Internet. The easiest way is simply to make audio files available for download. Compressed formats such as MP3 are the most popular, but any type of audio file can be delivered through a Web site or an FTP site, allowing users to store the file on their own system, and do with it what they will.

A more complex way to deliver audio (or video) over the Internet is called streaming. Streaming media flows from the Internet directly to a user's sound card. It isn't stored on the user's computer, but only played. Streaming makes it possible to deliver a continuous broadcast over the Internet, and is thus the basis of an Internet "radio station".

The streaming model has several advantages over the downloading model. First, it allows for a program of any length, or even a live broadcast. Second, it makes piracy easier to control, since users only listen to a piece of music, rather than storing it on their hard drives. Third, it's simpler for users. Why bother with storing files on your own machine if you can stream music on demand?

The technical centerpiece of an Internet radio station is a piece of software called a streaming media server. Just as a Web server delivers Web pages, a streaming media server delivers audio or video streams. There are three main players in the streaming media game these days: RealNetworks, Apple and Microsoft. All three offer both streaming servers and streaming media clients with their own native media formats. Also worth checking out, especially if you're on a low budget, is ShoutCast, a free server that streams MP3 files.

Streaming media works through a triad of software packages - the encoder, the server and the player. The encoder converts audio (or video) content into a streaming format, the server makes the content available over the Internet, and the player (on the end user's machine) retrieves the content.

Each of the big three streaming software makers makes a set of these three components. The players are all pretty good about playing each others' formats, so which player the user has makes little difference. The encoder and server work together, however, so if you have (for example) the RealNetworks streaming media server, you must use their RealProducer encoder.

Pre-recorded material is prepared for streaming using the encoder, then simply stored on the server, just like a Web page or other downloadable file. For a live broadcast, however, the encoder must work together with the server in real time. An audio feed runs to the sound card of a computer running the encoder software at the broadcast location (this should be a dedicated machine). From there the stream is uploaded to the streaming server, which may of course be at a different location.

Do you need to buy and install your own streaming media server? Of course not. Most major ISPs offer streaming media as either a standard feature or an upgrade to their server packages. Streaming pre-recorded content is pretty straightforward, and could be done with an ordinary hosting account or virtual server account. Live broadcasting is a bit more complex, since the encoder must run in real time at the broadcast location, and because of the large amount of computing resources required. If you're serious about live broadcasting, you'll probably want a dedicated server account.

Building an Internet Radio Station
Building an Internet Radio Station
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