Media UK

Streaming audio formats

Streaming audio is one of the potential growth areas for radio at present; particularly for small stations, RSLs, and local stations, their Reach can be drastically extended by allowing people to listen over the Internet.

However, the market is highly fragmented between several different, incompatible formats, making it difficult for the listener to know whether they have the right software installed (or indeed whether the right software is available for their computer!).

The major formats, at present, are as follows:

RealAudio:

• Pros; The BBC use it, so many of your potential listeners will already have the software installed. Very good performance at low bitrates. A long-standing platform with client support for every major operating system.

• Cons; The player has been known to go through phases of unreliability, and there is only one source; as the downloadable player is (in part) advertising-supported, there is substantial sentiment against it from some quarters. The server is either highly limited (in terms of numbers of simultaneous clients) or expensive, which is a problem for stations on a limited budget.

Windows Media:

• Pros: Excellent support on Windows; good sound quality at low bitrates.

• Cons: Server software only available for Windows; poor client support on non-Windows platforms (Windows Media Player is not installed by default on Macs, and there is no official support for Linux whatsoever).

MP3:

• Pros: Unbeatable market penetration; everyone has an MP3 player on their computer (be it Winamp (http://www.winamp.com/), Windows Media Player (http://www.microsoft.com/windows/windowsmedia/), iTunes (http://www.apple.com/itunes/) or XMMS (http://www.xmms.org/)). Server software is available under a Free Software license (Icecast (http://www.icecast.org/), for instance).

• Cons: Notably poor performance at low bitrates; outstanding patent issues still surround the MP3 codec.

Ogg Vorbis:

• Pros: Entirely [Free Software (http://www.opensource.org)]; does not have the patent problems of MP3. Good performance at low bitrates, and in general slightly better sound quality than MP3 at comparable bitrates. The Icecast (http://www.icecast.org/) streaming server is mature, stable, and free.

• Cons: Market penetration is poor; neither Windows or MacOS X ship with an Ogg Vorbis player. If you use this format exclusively, you will need to handhold your listeners through it - such as by supplying an applet on your website which can play your stream. An example is the free jlGui (http://www.javazoom.net/jlgui/jlgui.html) Java player, which depends on your listeners having working Java support; an example of this being deployed is the player at CUR1350 (http://www.cur1350.co.uk/). Encoding and decoding of Ogg Vorbis is quite CPU-hungry compared to other formats.

Quicktime:

• Pros: The Apple codec of choice. Notably good performance at low bitrates.

• Cons: Streaming support is limited; only Apple Macs have this pre-installed (though iTunes installs it automatically too).

Related links

• Real Networks (http://www.real.com)
• Windows Media Player (http://www.microsoft.com/windows/mediaplayer)
• SHOUTcast (http://www.shoutcast.com)
• IceCast (http://www.icecast.org)
• Ogg Vorbis (http://www.vorbis.com)
• Quicktime (http://www.apple.com/quicktime)