acmDriverEnum function (msacm.h)

Article
02/22/2024

The acmDriverEnum function enumerates the available ACM drivers, continuing until there are no more drivers or the callback function returns FALSE.

Syntax

MMRESULT ACMAPI acmDriverEnum(
  ACMDRIVERENUMCB fnCallback,
  DWORD_PTR       dwInstance,
  DWORD           fdwEnum
);

Parameters

fnCallback

Procedure instance address of the application-defined callback function.

dwInstance

A 64-bit (DWORD_PTR) or 32-bit (DWORD) application-defined value that is passed to the callback function along with ACM driver information.

fdwEnum

Flags for enumerating ACM drivers. The following values are defined.

Value	Meaning
ACM_DRIVERENUMF_DISABLED	Disabled ACM drivers should be included in the enumeration. Drivers can be disabled by the user through the Control Panel or by an application using the acmDriverPriority function. If a driver is disabled, the fdwSupport parameter to the callback function will have the ACMDRIVERDETAILS_SUPPORTF_DISABLED flag set.
ACM_DRIVERENUMF_NOLOCAL	Only global drivers should be included in the enumeration.

Return value

Returns zero if successful or an error otherwise. Possible error values include the following.

Return code	Description
MMSYSERR_INVALFLAG	At least one flag is invalid.
MMSYSERR_INVALPARAM	At least one parameter is invalid.

Remarks

The acmDriverEnum function will return MMSYSERR_NOERROR (zero) if no ACM drivers are installed. Moreover, the callback function will not be called.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	msacm.h
Library	Msacm32.lib
DLL	Msacm32.dll