acmFormatTagEnumW function (msacm.h)

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 acmFormatTagEnumW(
  HACMDRIVER             had,
  LPACMFORMATTAGDETAILSW paftd,
  ACMFORMATTAGENUMCBW    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.

Note

The msacm.h header defines acmFormatTagEnum as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

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

See also

Audio Compression Functions

Audio Compression Manager