IDirectMusicPort8 Interface
The IDirectMusicPort8 interface represents a device that sends or receives sound data. Examples are the input port of an MPU-401, the output port of an MPU-401, the Microsoft software synthesizer, and an IHV-provided filter. A physical device such as an MPU-401 might provide multiple ports. A single port, however, cannot both capture and render data.
IDirectMusicPort8 is a define for IDirectMusicPort. The two interface names are interchangeable.
The interface is typically obtained by using the IDirectMusic8::CreatePort method.
For an overview, see Using DirectMusic Ports.
In addition to the methods inherited from IUnknown, the IDirectMusicPort8 interface exposes the following methods, arranged by category.
Buffers
| Method | Description |
| PlayBuffer | Cues a buffer for playback by the port. |
| Read | Fills a buffer with incoming MIDI data. |
| SetReadNotificationHandle | Specifies an event that is to be set when MIDI messages are available to be read with the Read method. |
Devices
| Method | Description |
| Activate | Activates or deactivates the port. |
| DeviceIoControl | Calls the Win32 DeviceIoControl function on the underlying file handle implementing the port. |
| SetDirectSound | Overrides the default DirectSound device object or buffer, or both, to which a port's waveform data is streamed. |
DLS data
| Method | Description |
| Compact | Instructs the port to compact DLS or wave-table memory, thus making the largest possible contiguous chunk of memory available for new instruments to be downloaded. |
| DownloadInstrument | Downloads an instrument to the DLS device. |
| UnloadInstrument | Unloads a previously downloaded DLS instrument. |
Information retrieval
| Method | Description |
| GetCaps | Retrieves the port's capabilities. |
| GetFormat | Retrieves information about the WAV format specified in the DMUS_PORTPARAMS8 structure passed to IDirectMusic8::CreatePort, and the recommended size of the buffer to use for waveform output. |
| GetLatencyClock | Retrieves a pointer to the port's latency clock. |
| GetRunningStats | Retrieves information about the state of the synthesizer. |
MIDI Channels
| Method | Description |
| GetChannelPriority | Retrieves the priority of a MIDI channel. |
| GetNumChannelGroups | Retrieves the number of channel groups on the port. |
| SetChannelPriority | Sets the priority of a MIDI channel. |
| SetNumChannelGroups | Changes the number of channel groups that the application needs on the port. |
The LPDIRECTMUSICPORT8 type is defined as a pointer to the IDirectMusicPort8 interface.
typedef IDirectMusicPort8 *LPDIRECTMUSICPORT8;
Requirements
** Header:** Dmusicc.h
See Also