ACMDRIVERENUMCB callback function (msacm.h)

Article
02/22/2024

The acmDriverEnumCallback function specifies a callback function used with the acmDriverEnum function. The acmDriverEnumCallback name is a placeholder for an application-defined function name.

Syntax

ACMDRIVERENUMCB Acmdriverenumcb;

BOOL Acmdriverenumcb(
  HACMDRIVERID hadid,
  DWORD_PTR dwInstance,
  DWORD fdwSupport
)
{...}

Parameters

hadid

Handle to an ACM driver identifier.

dwInstance

Application-defined value specified in acmDriverEnum.

fdwSupport

Driver-support flags specific to the driver specified by ACMDRIVERDETAILS structure. This parameter can be a combination of the following values.

Value	Meaning
ACMDRIVERDETAILS_SUPPORTF_ASYNC	Driver supports asynchronous conversions.
ACMDRIVERDETAILS_SUPPORTF_CODEC	Driver supports conversion between two different format tags. For example, if a driver supports compression from WAVE_FORMAT_PCM to WAVE_FORMAT_ADPCM, this flag is set.
ACMDRIVERDETAILS_SUPPORTF_CONVERTER	Driver supports conversion between two different formats of the same format tag. For example, if a driver supports resampling of WAVE_FORMAT_PCM, this flag is set.
ACMDRIVERDETAILS_SUPPORTF_DISABLED	Driver has been disabled. An application must specify the ACM_DRIVERENUMF_DISABLED flag with acmDriverEnum to include disabled drivers in the enumeration.
ACMDRIVERDETAILS_SUPPORTF_FILTER	Driver supports a filter (modification of the data without changing any of the format attributes). For example, if a driver supports volume or echo operations on WAVE_FORMAT_PCM, this flag is set.

Return value

The callback function must return TRUE to continue enumeration or FALSE to stop enumeration.

Remarks

The acmDriverEnum function will return MMSYSERR_NOERROR (zero) if no ACM drivers are installed. Moreover, the callback function will not be called.

The following functions should not be called from within the callback function: acmDriverAdd, acmDriverRemove, and acmDriverPriority.

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