acmFormatSuggest function (msacm.h)

The acmFormatSuggest function queries the ACM or a specified ACM driver to suggest a destination format for the supplied source format. For example, an application can use this function to determine one or more valid PCM formats to which a compressed format can be decompressed.

Syntax

MMRESULT ACMAPI acmFormatSuggest(
  HACMDRIVER     had,
  LPWAVEFORMATEX pwfxSrc,
  LPWAVEFORMATEX pwfxDst,
  DWORD          cbwfxDst,
  DWORD          fdwSuggest
);

Parameters

had

Handle to an open instance of a driver to query for a suggested destination format. If this parameter is NULL, the ACM attempts to find the best driver to suggest a destination format.

pwfxSrc

Pointer to a WAVEFORMATEX structure that identifies the source format for which a destination format will be suggested by the ACM or specified driver.

pwfxDst

Pointer to a WAVEFORMATEX structure that will receive the suggested destination format for the pwfxSrc format. Depending on the fdwSuggest parameter, some members of the structure pointed to by pwfxDst may require initialization.

cbwfxDst

Size, in bytes, available for the destination format. The acmMetrics and acmFormatTagDetails functions can be used to determine the maximum size required for any format available for the specified driver (or for all installed ACM drivers).

fdwSuggest

Flags for matching the desired destination format. The following values are defined.

Value	Meaning
ACM_FORMATSUGGESTF_NCHANNELS	The nChannels member of the structure pointed to by pwfxDst is valid. The ACM will query acceptable installed drivers that can suggest a destination format matching nChannels or fail.
ACM_FORMATSUGGESTF_NSAMPLESPERSEC	The nSamplesPerSec member of the structure pointed to by pwfxDst is valid. The ACM will query acceptable installed drivers that can suggest a destination format matching nSamplesPerSec or fail.
ACM_FORMATSUGGESTF_WBITSPERSAMPLE	The wBitsPerSample member of the structure pointed to by pwfxDst is valid. The ACM will query acceptable installed drivers that can suggest a destination format matching wBitsPerSample or fail.
ACM_FORMATSUGGESTF_WFORMATTAG	The wFormatTag member of the structure pointed to by pwfxDst is valid. The ACM will query acceptable installed drivers that can suggest a destination format matching wFormatTag or fail.

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.

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