IDirectMusicBuffer8 Interface
The IDirectMusicBuffer8 interface represents a buffer containing time-stamped data (typically in the form of MIDI messages) being sequenced to a port. The buffer contains a small amount of data, typically less than 200 milliseconds. Unless your application is doing its own sequencing, you do not need to use the methods of this interface.
IDirectMusicBuffer8 is a type definition for IDirectMusicBuffer. The two interface names are interchangeable.
Buffer objects are completely independent of port objects until the buffer is passed to the port by a call to the IDirectMusicPort8::PlayBuffer or the IDirectMusicPort8::Read method. The application is then free to reuse the buffer.
In addition to the methods inherited from IUnknown, the IDirectMusicBuffer8 interface exposes the following methods.
| Method | Description |
| Flush | Discards all data in the buffer. |
| GetBufferFormat | Retrieves the GUID that represents the buffer format. |
| GetMaxBytes | Retrieves the number of bytes that can be stored in the buffer. |
| GetNextEvent | Returns information about the next message in the buffer and advances the read pointer. |
| GetRawBufferPtr | Returns a pointer to the underlying buffer data structure. |
| GetStartTime | Retrieves the start time of the data in the buffer, relative to the master clock. |
| GetUsedBytes | Retrieves the number of bytes of data in the buffer. |
| PackStructured | Inserts fixed-length data (typically a MIDI channel message), along with timing and routing information, into the buffer. |
| PackUnstructured | Inserts unstructured data (typically a MIDI system-exclusive message), along with timing and routing information, into the buffer |
| ResetReadPtr | Sets the read pointer to the start of the data in the buffer. |
| SetStartTime | Sets the start time of the data in the buffer, relative to the master clock. |
| SetUsedBytes | Sets the number of bytes of data in the buffer. |
| TotalTime | Returns the total time spanned by the data in the buffer. |
The LPDIRECTMUSICBUFFER8 type is defined as a pointer to the IDirectMusicBuffer8 interface:
typedef IDirectMusicBuffer8 *LPDIRECTMUSICBUFFER8;
Requirements
** Header:** Dmusicc.h
See Also