(PECL openal >= 0.1.0)
openal_buffer_get — Retrieve an OpenAL buffer property
$buffer, int $property): int|falsebufferAn Open AL(Buffer) resource (previously created by openal_buffer_create()).
property
      Specific property, one of:
      AL_FREQUENCY,
      AL_BITS,
      AL_CHANNELS 和 
      AL_SIZE.
     
   Returns an integer value appropriate to the property
   requested 或者在失败时返回 false.