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This message requests an ACM driver to return hardware capabilities for a waveform output device.
Parameters
- dwDriverID
- Specifies a driver instance identifier. The driver returns this value in response to the ACM_Openfunction.
- hDriver
- Handle to a driver.
- uMsg
- Specifies this message.
- lParam1
- Pointer to a WAVEOUTCAPSstructure declared in the Mmsystem.h header file.
- lParam2
- Size of the
WAVEOUTCAPSstructure pointed to by
lParam1.
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. If the driver does not support waveform hardware, it returns MMSYSERR_NOTSUPPORTED.
Remarks
The ACM (Waveapi.dll) sends this message by calling the ACM driver's ACM_IOControlentry point through the DeviceIoControlfunction. This call is made each time a client calls the acmMetricsfunction with the index parameter of ACM_METRIC_HARDWARE_WAVE_OUTPUT.
The driver receives the address of WAVEOUTCAPSand fills in the structure.
Only ACM drivers that provide access to waveform output hardware need to support this message. If your driver supports this message, it must return ACMDRIVERDETAILS_SUPPORTF_HARDWARE in the ACMDRIVERDETAILSstructure provided with the ACMDM_DRIVER_DETAILS message. For more information about providing ACM support, see the Windows NT DDK.
Requirements
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