acmDriverAdd function (msacm.h)
The acmDriverAdd function adds a driver to the list of available ACM drivers. The driver type and location are dependent on the flags used to add ACM drivers. After a driver is successfully added, the driver entry function will receive ACM driver messages.
Syntax
MMRESULT ACMAPI acmDriverAdd(
LPHACMDRIVERID phadid,
HINSTANCE hinstModule,
LPARAM lParam,
DWORD dwPriority,
DWORD fdwAdd
);
Parameters
phadid
Pointer to the buffer that receives a handle identifying the installed driver. This handle is used to identify the driver in calls to other ACM functions.
hinstModule
Handle to the instance of the module whose executable or dynamic-link library (DLL) contains the driver entry function.
lParam
Driver function address or a notification window handle, depending on the fdwAdd flags.
dwPriority
Window message to send for notification broadcasts. This parameter is used only with the ACM_DRIVERADDF_NOTIFYHWND flag. All other flags require this member to be set to zero.
fdwAdd
Flags for adding ACM drivers. The following values are defined.
| Value | Meaning |
|---|---|
| ACM_DRIVERADDF_FUNCTION | The lParam parameter is a driver function address conforming to the acmDriverProc prototype. The function may reside in either an executable or DLL file. |
| ACM_DRIVERADDF_GLOBAL | Provided for compatibility with 16-bit applications. For the Win32 API, ACM drivers added by the acmDriverAdd function can be used only by the application that added the driver. This is true whether or not ACM_DRIVERADDF_GLOBAL is specified. For more information, see Adding Drivers Within an Application. |
| ACM_DRIVERADDF_LOCAL | The ACM automatically gives a local driver higher priority than a global driver when searching for a driver to satisfy a function call. For more information, see Adding Drivers Within an Application. |
| ACM_DRIVERADDF_NAME | The lParam parameter is a registry value name in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32. The value identifies a DLL that implements an ACM codec. Applications can use this flag if new registry entries are created after the application has already started using the ACM. |
| ACM_DRIVERADDF_NOTIFYHWND | The lParam parameter is a handle of a notification window that receives messages when changes to global driver priorities and states are made. The window message to receive is defined by the application and must be passed in dwPriority. The wParam and lParam parameters passed with the window message are reserved for future use and should be ignored. ACM_DRIVERADDF_GLOBAL cannot be specified in conjunction with this flag. For more information about driver priorities, see the description for the acmDriverPriority function. |
Return value
Returns zero if successful or an error otherwise. Possible error values include the following.
| Return code | Description |
|---|---|
|
At least one flag is invalid. |
|
At least one parameter is invalid. |
|
The system is unable to allocate resources. |
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 |