What is Bit Rate in MP3?

change mp3 bit-rate on the fly (php, linux)

• I have a large library of mp3s and need to figure out a way to stream low quality versions to dial-up web users. I figure there must be a way to change the bit-rate of the high-bit-rate mp3 without actually changing the file or having to make 2 copies. This needs to be a server side (linux) solution. NOT software for converting mp3s. Again, this is a VERY large catalog of mp3s and having 2 files for each song with different bit-rates is NOT an option. I have seen other sites that do this with .m3u. Thanks!

• Answer:

  Dear isoundcom, The solution to your problem is a pair of free software packages published by the Shoutcast crew. The first is the Shoutcast streaming server, downloadable as a precompiled Linux binary. See the third entry on the following page. Shoutcast: Downloading http://www.shoutcast.com/download/files.phtml The Shoutcast server itself doesn't do any mp3 decoding or transcoding, since it expects a stream from a separate audio player or from one of its input plugins. One such plugin is Shoutcast DSP (Digital Signal Processing). The DSP plugin comes as part of a package variously called the Shoutcast Broadcasting Tools or Shoutcast Trans. You can download it using the first link below the header at the following address. Shoutcast: Shoutcast Broadcasting Tools http://www.shoutcast.com/download/broadcast.phtml#posixdownload What you get with the package is a precompiled Linux binary called sc_trans_linux, which will take care of launching the Shoutcast server and feeding it an audio stream at the bitrate you specify. You'll also have to make one or more playlists to specify the directories from which you wish to stream files, and specify other settings in the configuration file. Full details are given on the following page. The pathnames in this tutorial may differ from those on your machine, but the principles are the same. See section 3, "Setting up SHOUTcast Trans". The Bitrate setting lets you specify the streaming rate of your mp3 files in bits per second. Gentoo: Chris White: Streaming Radio With SHOUTcast http://www.gentoo.org/doc/en/shoutcast-config.xml?style=printable It has been a pleasure to address this question on your behalf. If you find fault with my answer, please inform me through a Clarification Request so that I may fully meet your needs before you assign a rating. Regards, leapinglizard