预定义常量

下列常量由此扩展定义，且仅在此扩展编译入 PHP 或在运行时动态载入时可用。

**OGG/Vorbis supports PCM encodings in the following formats**
Constant	Definition
`OGGVORBIS_PCM_U8`	Unsigned 8-bit PCM.
`OGGVORBIS_PCM_S8`	Signed 8-bit PCM.
`OGGVORBIS_PCM_U16_LE`	Unsigned 16-bit PCM. Little Endian byte order.
`OGGVORBIS_PCM_U16_BE`	Unsigned 16-bit PCM. Big Endian byte order.
`OGGVORBIS_PCM_S16_LE`	Signed 16-bit PCM. Little Endian byte order.
`OGGVORBIS_PCM_S16_BE`	Signed 16-bit PCM. Big Endian byte order.