Why do web radio broadcasts lag?

[DannyG]

I was comparing a web radio broadcast to an actual analogue standard radio, and I noticed the web radio was around 2 minutes behind. Is there a technical reason for this?

[ge0dotorg]

This is usually due to the fact that the audio has to be encoded to a lower quality from the original output and this encoding process takes time. Broadcasting radio over the web usually involves taking an existing feed of the station, either direct from the main feed to the transmitted, or much easier receiveing it over the air using an analogue or digital receiever and encoding that.

[DannyG]

Why does it need to be encoded to a lower quality? And would that process *really* take 2 minutes?

[dudley1977]

Lot's of reasons. The first respondent was right, the encoding takes several seconds however the music file has to be uploaded from the machine doing the compression to the live streaming server. Most large websites doing streaming duplicate the files on servers all around the world to reduce the time it takes to get the file - and to increase capacity. The copying process can take several minutes too. Finally, your realplayer or quicktime plug-in will 'buffer' for up to 10 seconds before playing back the file on your machine, to make sure it can continue to play even when the stream is interrupted. With all this in mind, you're lucky it was just a 2 minute lag!