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PHP5中文手册
oggvorbis
简介
The OGG/Vorbis file format, as defined by » 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.
运行时配置
本扩展模块在 php.ini 中未定义任何配置选项。
Context options
OGG/Vorbis tuning options
| Option |
Definition |
Relevance |
Default |
| pcm_mode |
PCM byte encoding used. See constants below. |
Read / Write |
OGGVORBIS_PCM_S16_LE |
| rate |
PCM Sampling rate. Measured in Hz. |
Write only |
44100 |
| bitrate |
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
|
Write only |
array('ENCODER' => 'PHP/OggVorbis, http://pear.php.net/oggvorbis') |
预定义常量
以下常量由本扩展模块定义，因此只有在本扩展模块被编译到
PHP 中，或者在运行时被动态加载后才有效。
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. |
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