DMUS_PORTCAPS
The DMUS_PORTCAPS structure contains information about a port enumerated by a call to the IDirectMusic8::EnumPort method. The structure is also used to return information through the IDirectMusicPort8::GetCaps method.
Syntax
typedef struct _DMUS_PORTCAPS {
DWORD dwSize;
DWORD dwFlags;
GUID guidPort;
DWORD dwClass;
DWORD dwType;
DWORD dwMemorySize;
DWORD dwMaxChannelGroups;
DWORD dwMaxVoices;
DWORD dwMaxAudioChannels;
DWORD dwEffectFlags;
WCHAR wszDescription[DMUS_MAX_DESCRIPTION];
} DMUS_PORTCAPS, *LPDMUS_PORTCAPS;
Members
dwSize
Size of the structure, in bytes. This member must be initialized to sizeof(DMUS_PORTCAPS) before the structure is passed to any method.
dwFlags
Flags describing various capabilities of the port. This field can contain one or more of the following values:
| Flag | Description |
| DMUS_PC_AUDIOPATH | Multiple outputs can be connected to DirectSound for audiopaths. |
| DMUS_PC_DIRECTSOUND | The port supports streaming waveform data to DirectSound. |
| DMUS_PC_DLS | The port supports DLS Level 1 sample collections. |
| DMUS_PC_DLS2 | The port supports DLS Level 2 sample collections. |
| DMUS_PC_EXTERNAL | The port connects to devices outside the host—for example, devices connected over an external MIDI port such as the MPU-401. |
| DMUS_PC_GMINHARDWARE | The synthesizer has its own GM instrument set, so GM instruments do not need to be downloaded. |
| DMUS_PC_GSINHARDWARE | This port contains the Roland GS sound set in hardware. |
| DMUS_PC_MEMORYSIZEFIXED | Memory available for DLS instruments cannot be adjusted. |
| DMUS_PC_SHAREABLE | More than one port can be created that uses the same range of channel groups on the device. Unless this bit is set, the port can be opened only in exclusive mode. In exclusive mode, an attempt to create a port fails unless free channel groups are available to assign to the create request. |
| DMUS_PC_SOFTWARESYNTH | The port is a software synthesizer. |
| DMUS_PC_WAVE | Streaming and one-shot waveforms are supported. |
| DMUS_PC_XGINHARDWARE | The port contains the Yamaha XG extensions in hardware. |
guidPort
Identifier of the port. This value can be passed to the IDirectMusic8::CreatePort method to get an IDirectMusicPort8 interface for the port.
dwClass
Class of this port. The following classes are defined:
| Value | Description |
| DMUS_PC_INPUTCLASS | Input port. |
| DMUS_PC_OUTPUTCLASS | Output port. |
dwType
Type of this port. The following types are defined:
| Value | Description |
| DMUS_PORT_WINMM_DRIVER | Windows multimedia driver. |
| DMUS_PORT_USER_MODE_SYNTH | User-mode synthesizer. |
| DMUS_PORT_KERNEL_MODE | WDM driver. |
dwMemorySize
Amount of memory available to store DLS instruments. If the port is using system memory and the amount is therefore limited only by the available system memory, this member contains DMUS_PC_SYSTEMMEMORY.
dwMaxChannelGroups
Maximum number of channel groups supported by this port. A channel group is a set of 16 MIDI channels.
dwMaxVoices
Maximum number of voices that can be allocated when this port is opened. The value can be –1 if the driver does not support returning this parameter.
dwMaxAudioChannels
Maximum number of audio channels that can be rendered by the port. The value can be –1 if the driver does not support returning this parameter.
dwEffectFlags
Flags indicating what audio effects are available on the port.
The following flags are defined:
| Flag | Description |
| DMUS_EFFECT_NONE | No effects are supported. |
| DMUS_EFFECT_REVERB | The port supports reverb. |
| DMUS_EFFECT_CHORUS | The port supports chorus. |
| DMUS_EFFECT_DELAY | The port supports delay. |
wszDescription
Description of the port. This can be a system-generated name, such as L"MPU-401 Output Port [330]", or a user-specified friendly name, such as L"Port w/ External SC-55".
Requirements
** Minimum Supported Client:** Windows 2000.
** Minimum Supported Server:** Windows 2000 Server.
** Header:** Dmusicc.h
See Also