ogg:// — Audio streams
   Files opened for reading via the ogg:// wrapper
   are treated as compressed audio encoded using the OGG/Vorbis codec.
   Similarly, files opened for writing or appending via the
   ogg:// wrapper are writen as compressed audio data.
   stream_get_meta_data(), when used on an OGG/Vorbis
   file opened for reading will return various details about the stream
   including the vendor tag, any included
   comments, the number of
   channels, the sampling rate,
   and the encoding rate range described by:
   bitrate_lower, bitrate_upper,
   bitrate_nominal, and bitrate_window.
  
ogg:// PHP 4.3.0 and up (PECL)
Note: This wrapper is not enabled by default
In order to use the ogg:// wrapper you must install the » OGG/Vorbis extension available from » PECL.