The MXDM_GETLINEINFO message requests a user-mode mixer driver to return information about a specified audio line for the specified device.
Parameters
uDeviceId
Device identifier (0, 1, 2, and so on) for the target device.
uMsg
MXDM_GETLINEINFO
dwUser
Instance identifier associated with the caller.
lParam1
Pointer to a MIXERLINE structure, which is described in the Win32 SDK.
lParam2
Contains flag values. For a list of valid flags, see the description of mixerGetLineInfo in the Win32 SDK.
Return Value
The driver should return MMSYSERR_NOERROR if the operation succeeds. Otherwise it should return one of the MMSYSERR or MIXERR error codes defined in mmsystem.h. See mixerGetLineInfo return values in the Win32 SDK.
Comments
A client sends the MXDM_GETLINEINFO message by calling the user-mode driver's mxdMessage entry point, passing the specified parameters.
The driver receives an empty MIXERLINE structure and fills it in.