IMFTransform::GetStreamLimits method (mftransform.h)

Gets the minimum and maximum number of input and output streams for this Media Foundation transform (MFT).

Syntax

HRESULT GetStreamLimits(
  [out] DWORD *pdwInputMinimum,
  [out] DWORD *pdwInputMaximum,
  [out] DWORD *pdwOutputMinimum,
  [out] DWORD *pdwOutputMaximum
);

Parameters

[out] pdwInputMinimum

Receives the minimum number of input streams.

[out] pdwInputMaximum

Receives the maximum number of input streams. If there is no maximum, receives the value MFT_STREAMS_UNLIMITED.

[out] pdwOutputMinimum

Receives the minimum number of output streams.

[out] pdwOutputMaximum

Receives the maximum number of output streams. If there is no maximum, receives the value MFT_STREAMS_UNLIMITED.

Return value

If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

If the MFT has a fixed number of streams, the minimum and maximum values are the same.

It is not recommended to create an MFT that supports zero inputs or zero outputs. An MFT with no inputs or no outputs may not be compatible with the rest of the Media Foundation pipeline. You should create a Media Foundation sink or source for this purpose instead.

When an MFT is first created, it is not guaranteed to have the minimum number of streams. To find the actual number of streams, call IMFTransform::GetStreamCount.

This method should not be called with NULL parameters, although in practice some implementations may allow NULL parameters.

If MFT_UNIQUE_METHOD_NAMES is defined before including mftransform.h, this method is renamed MFTGetStreamLimits. See Creating Hybrid DMO/MFT Objects.

Requirements

See also

IMFTransform

Media Foundation Transforms