acmFormatTagEnum function (msacm.h)

Article
02/22/2024

The acmFormatTagEnum function enumerates waveform-audio format tags available from an ACM driver. This function continues enumerating until there are no more suitable format tags or the callback function returns FALSE.

Syntax

MMRESULT ACMAPI acmFormatTagEnum(
  HACMDRIVER            had,
  LPACMFORMATTAGDETAILS paftd,
  ACMFORMATTAGENUMCB    fnCallback,
  DWORD_PTR             dwInstance,
  DWORD                 fdwEnum
);

Parameters

had

Handle to the ACM driver to query for waveform-audio format tag details. If this parameter is NULL, the ACM uses the details from the first suitable ACM driver.

paftd

Pointer to the ACMFORMATTAGDETAILS structure that is to receive the format tag details passed to the function specified in fnCallback. This structure must have the cbStruct member of the ACMFORMATTAGDETAILS structure initialized.

fnCallback

Procedure instance address of the application-defined callback function.

dwInstance

A 64-bit (DWORD_PTR) or 32-bit (DWORD) application-defined value that is passed to the callback function along with ACM format tag details.

fdwEnum

Reserved; must be zero.

Return value

Returns zero if successful or an error otherwise. Possible error values include the following.

Return code	Description
MMSYSERR_INVALFLAG	At least one flag is invalid.
MMSYSERR_INVALHANDLE	The specified handle is invalid.
MMSYSERR_INVALPARAM	At least one parameter is invalid.

Remarks

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

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
Library	Msacm32.lib
DLL	Msacm32.dll