IMFDeviceTransform::SetOutputStreamState method (mftransform.h)

The SetOutputStreamState method sets the Device MFT output stream state and media type.

Syntax

HRESULT SetOutputStreamState(
  [in] DWORD             dwStreamID,
  [in] IMFMediaType      *pMediaType,
  [in] DeviceStreamState value,
  [in] DWORD             dwFlags
);

Parameters

[in] dwStreamID

Stream ID of the input stream where the state and media type needs to be changed.

[in] pMediaType

Preferred media type for the input stream is passed in through this parameter. Device MFT should change the media type only if the incoming media type is different from the current media type.

[in] value

Specifies the DeviceStreamState which the input stream should transition to.

[in] dwFlags

Must be zero.

Return value

The method returns an HRESULT. Possible values include but not limited to values given in the following table.

Remarks

This interface method helps to transition the output stream to a specified state with specified media type set on the output stream. This will be used by the DTM when the Device Source requests a specific output stream’s state and media type to be changed. Device MFT should change the specified output stream’s media type and state to the requested media type.

If the incoming media type and stream state are same as the current media type and stream state the method return S_OK.

If the incoming media type and current media type of the stream are the same, Device MFT must change the stream’s state to the requested value and return the appropriate HRESULT.

When a change in the output stream’s media type requires a corresponding change in the input then Device MFT must post the METransformInputStreamStateChanged event to DTM to change the relevant input stream. The call must return only after changing the input stream’s media type and the appropriate HRESULT.

As an example, consider a Device MFT that has two input streams and three output streams. Let Output 1 and Output 2 source from Input 1 and stream at 720p. Now, let us say Output 2’s media type changes to 1080p. To satisfy this request, Device MFT must change the Input 1 media type to 1080p, by posting METransformInputStreamStateChanged event to the DTM. DTM would call SetInputStreamState to change the input stream’ media type and state. After this call, the SetOutputStreamState must return.

Requirements

See also

IMFDeviceTransform