(PECL openal >= 0.1.0)
openal_buffer_get — Retrieve an OpenAL buffer property
An Open AL(Buffer) resource (previously created by openal_buffer_create()).
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.