ogg://

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.