The OGG/Vorbis file format, as defined by http://www.vorbis.com/
and http://www.vorbis.com/, is a scheme
for compressing audio streams by multiple factors with a minimum of
quality loss. This extension adds Ogg Vorbis support to PHP's
URL Wrappers. When used in read mode,
compressed OGG/Vorbis data is expanded to raw PCM audio in one of six PCM
encoding formats listed below.
oggvorbis is installed through the usual PECL package installation process.
$ pear install oggvorbis
Copy the resulting oggvorbis.so to an appropriate
location and add extension=oggvorbis.so to your
php.ini file or load it dynamically in your PHP script using
dl('oggvorbis.so');
Vorbis Average Bitrate Encoding / Variable Bitrate Encoding.
Measured in bps (ABR) or Quality level (VBR: 0.0 to 1.0).
128000 ABR is rough equal to 0.4 VBR.
Write only
128000
channels
Number of PCM channels. 1 == Mono, 2 == Stereo.
Write only
2
serialno
Serial Number of stream within file. Must be unique within file.
Because of the potential to select a duplicate serial number within
a chained file, make efforts to manually assign unique numbers when
encoding.
Write only
Random
comments
Associative array of file comments.
Will be translated to strtoupper($name) . "=$value".
Note: This context option is not available in oggvorbis-0.1
Перечисленные ниже константы определены данным расширением и могут быть
доступны только в том случае, если PHP был собран с
поддержкой этого расширения или же в том случае, если
данное расширение подгружается во время выполнения.
Таблица 2. OGG/Vorbis supports PCM encodings in the following formats