The ACM_OPEN message opens an AVI clip and displays its first frame in an animation control. You can send this message explicitly or by using the Animate_Open macro.
ACM_OPEN wParam = 0; lParam = (LPARAM) (LPSTR) lpszName;
The AVI file or resource specified by lpszName must not contain audio. It must be silent.
If this parameter is NULL, the system closes the .AVI file that was previously opened for the specified animation control, if any.
If the operation succeeds, the return value is a nonzero value.
If the operation fails, the return value is zero.
You can only open silent AVI clips. AVI files or resources containing audio will not load. ACM_OPEN and Animate_Open fail if lpszSource specifies a non-silent AVI clip.
You can use Animate_Close to close an .AVI file or AVI resource that was previously opened for the specified animation control.
The Animate_Open and Animate_Close macros are defined in COMMCTRL.H.