HRESULT FreeSpace(DWORD dwBytes, BOOL fEOF);
Notifies the engine that the amount of data in the audio-destination object's internal buffer has changed.
� Return value is ignored.
dwBytes
[in] Number of bytes that are currently free in the object's internal buffer.
fEOF
[in] TRUE if an end-of-file character has been reached and no more data can be sent to the audio destination or FALSE if more data exists. If the audio destination is a wave-out device, this parameter is always FALSE.
An engine might respond to the FreeSpace notification by putting more data into the buffer.
This notification is not sent when the amount of data changes as a result of the engine's own actions, such as calling the IAudio::Flush or IAudioDest::DataSet member function.
For best performance, the audio-destination object should not send this notification more than 16 times per second.