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