Microsoft Windows CE 3.0  


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This message requests an ACM driver to close a conversion stream that was opened with an ACMDM_STREAM_OPEN message.


Specifies a driver instance identifier. The driver returns this value in response to the ACM_Openfunction.
Handle to a driver.
Specifies this message.
Pointer to an ACMDRVSTREAMINSTANCEstructure.
Not used.

Return Values

MMSYSERR_NOERROR indicates success. Otherwise, the driver returns one of the MMSYSERR error values declared in the Mmsystem.h header file or one of the ACMERR error values declared in the Msacm.h header file. An asynchronous driver might have to return ACMERR_BUSY if a conversion operation has not completed.


The ACM (Waveapi.dll) sends this message by calling the ACM driver's ACM_IOControlentry point through the DeviceIoControlfunction. The ACM sends this message when an application calls the acmStreamClosefunction.

All ACM drivers that provide stream conversions must support this message. For more information about stream conversions, see the Windows NT DDK.

If the driver supports asynchronous operations and the client has specified the ACM_STREAMOPENF_ASYNC flag, which is contained in the fdwOpenmember of ACMDRVSTREAMINSTANCE, the driver sends the client an MM_ACM_CLOSE callback message. It does this by calling the PostThreadMessagefunction after the operation completes.


Runs on Versions Defined in Include Link to
Windows CE OS 1.0 and later      
Note   This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.

 Last updated on Tuesday, July 13, 2004

© 2004 Microsoft Corporation. All rights reserved.