ACMDM_HARDWARE_WAVE_CAPS_OUTPUT (Windows Embedded CE 6.0)

1/6/2010

This message requests an ACM driver to return hardware capabilities for a waveform output device.

Parameters

• dwDeviceID
  Value that specifies a driver instance identifier. The driver returns this value in response to the ACM_Open (ACM Driver) function.

• hDriver
  Handle to a driver.

• uMsg
  Value that specifies this message.

• lParam1
  Pointer to a WAVEOUTCAPS structure declared in the Mmsystem.h header file.

• lParam2
  Value that specifies the size of the WAVEOUTCAPS structure pointed to by lParam1.

Return Values

A return value of 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_IOControl entry point through the DeviceIoControl function. This call is made each time a client calls the acmMetrics function with the index parameter of ACM_METRIC_HARDWARE_WAVE_OUTPUT. The driver then receives the address of WAVEOUTCAPS and populates 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 ACMDRIVERDETAILS structure provided with the ACMDM_DRIVER_DETAILS message.

Requirements

See Also

Reference

ACM_Open (ACM Driver)
ACM_IOControl

Concepts

ACM Driver Messages