This wrapper is not enabled by default:
In order to use the ogg:// wrapper you must install
the OGG/Vorbis extension
available from PECL.
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_nominal, and bitrate_window.
PCM encoding to apply while reading, one of:
OGGVORBIS_PCM_U16_LE, and OGGVORBIS_PCM_S16_LE.
(8 vs 16 bit, signed or unsigned, big or little endian)
Sampling rate of input data, expressed in Hz
When given as an integer, the fixed bitrate at which to encode. (16000 to 131072)
When given as a float, the variable bitrate quality to use. (-1.0 to 1.0)
The number of audio channels to encode, typically 1 (Mono), or 2 (Stero).
May range as high as 16.
An array of string values to encode into the track header.