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mixerGetLineInfo (Compact 2013)

  • Статья

3/26/2014

This function retrieves information about a specific line of a mixer device.

Syntax

MMRESULT mixerGetLineInfo(
  HMIXEROBJ hmxobj, 
  LPMIXERLINE pmxl, 
  DWORD fdwInfo 
);

Parameters

  • hmxobj
    Handle to the mixer device object that controls the specific audio line.

  • pmxl
    Pointer to a MIXERLINE structure.

    This structure is filled with information about the audio line for the mixer device.

    The cbStruct member must always be initialized to be the size, in bytes, of the MIXERLINE structure.

  • fdwInfo
    Flags for retrieving information about an audio line.

    The following table shows the possible flags.

    Flag

    Description

    MIXER_GETLINEINFOF_COMPONENTTYPE

    The pmxl parameter will receive information about the first audio line of the type specified in the dwComponentType member of the MIXERLINE structure.

    This flag is used to retrieve information about an audio line of a specific component type.

    Remaining structure members except cbStruct require no further initialization.

    MIXER_GETLINEINFOF_DESTINATION

    The pmxl parameter will receive information about the destination audio line specified by the dwDestination member of the MIXERLINE structure.

    This index ranges from zero to one less than the value in the cDestinations member of the MIXERCAPS structure.

    All remaining structure members except cbStruct require no further initialization.

    MIXER_GETLINEINFOF_LINEID

    The pmxl parameter will receive information about the audio line specified by the dwLineID member of the MIXERLINE structure.

    This is usually used to retrieve updated information about the state of an audio line.

    All remaining structure members except cbStruct require no further initialization.

    MIXER_GETLINEINFOF_SOURCE

    The pmxl parameter will receive information about the source audio line specified by the dwDestination and dwSource members of the MIXERLINE structure.

    The index specified by dwDestination ranges from zero to one less than the value in the cDestinations member of the MIXERCAPS structure.

    The index specified by dwSource ranges from zero to one less than the value in the cConnections member of the MIXERLINE structure returned for the audio line stored in the dwDestination member.

    All remaining structure members except cbStruct require no further initialization.

    MIXER_GETLINEINFOF_TARGETTYPE

    The pmxl parameter will receive information about the audio line for the Target.dwType member of MIXERLINE.

    This flag is used to retrieve information about an audio line that handles the target type (for example, MIXERLINE_TARGETTYPE_WAVEOUT).

    An application must initialize the Target.dwType, Target.wMid, Target.wPid, Target.vDriverVersion and Target.szPname members of the MIXERLINE structure before calling mixerGetLineInfo.

    All of these values can be retrieved from the device capabilities structures for all media devices.

    Remaining structure members except cbStruct require no further initialization.

    MIXER_OBJECTF_HMIXER

    The hmxobj parameter is a mixer device handle returned by the mixerOpen function.

    This flag is optional.

    MIXER_OBJECTF_MIXER

    The hmxobj parameter is a mixer device identifier in the range of zero to one less than the number of devices returned by the mixerGetNumDevs function.

    This flag is optional.

    The following flags are supported in other versions of Windows, but not in Windows Embedded Compact.

    Flags not supported in Windows Embedded Compact

    MIXER_OBJECTF_AUX

    MIXER_OBJECTF_HMIDIN

    MIXER_OBJECTF_HMIDIOUT

    MIXER_OBJECTF_HWAVEIN

    MIXER_OBJECTF_HWAVEOUT

    MIXER_OBJECTF_MIDIIN

    MIXER_OBJECTF_MIDIOUT

    MIXER_OBJECTF_WAVEHOUT

    MIXER_OBJECTF_WAVEIN

Return Value

Returns MMSYSERR_NOERROR if successful or an error otherwise.

The following table shows the possible values.

Value

Description

MIXERR_INVALLINE

The audio line reference is invalid.

MMSYSERR_BADDEVICEID

The hmxobj parameter specifies an invalid device identifier.

MMSYSERR_INVALFLAG

One or more flags are invalid.

MMSYSERR_INVALHANDLE

The hmxobj parameter specifies an invalid handle.

MMSYSERR_INVALPARAM

One or more parameters are invalid.

MMSYSERR_NODRIVER

No mixer device is available for the object specified by hmxobj.

Requirements

Header

mmsystem.h

Library

coredll.lib

See Also

Reference

Hardware Audio Mixer Functions
MIXERLINE
MIXERCAPS
mixerOpen
mixerGetNumDevs