Platform SDK: DirectX

DMUS_PORTCAPS

The DMUS_PORTCAPS structure receives information about a port enumerated by a call to the IDirectMusic::EnumPort method. The structure is also used to return information through the IDirectMusicPort::GetCaps method.

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:

DMUS_PC_DIRECTSOUND: The port supports streaming wave 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_XGINHARDWARE: The port contains the Yamaha XG extensions in hardware.

guidPort

Identifier of the port. This value can be passed to the IDirectMusic::CreatePort method to get an IDirectMusicPort interface for the port.

dwClass

Class of this port. The following classes are defined:

DMUS_PC_INPUTCLASS: Input port.
DMUS_PC_OUTPUTCLASS: Output port.

dwType

Type of this port. The following types are defined:

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 instruments. If the port is using system memory and the amount is therefore limited only by the available system memory, this field 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:

DMUS_EFFECT_NONE: No effects are supported.
DMUS_EFFECT_REVERB: The port supports reverb.
DMUS_EFFECT_CHORUS: The port supports chorus.

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

  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Header: Declared in dmusicc.h.