Microsoft DirectX 9.0


The Initialize method creates and initializes a new media stream with the specified stream type and purpose ID.


HRESULT Initialize(
  IUnknown *pSourceObject,
  DWORD dwFlags,
  const STREAM_TYPE StreamType



[in] Pointer to an IUnknown source object.


[in] Value that modifies the media stream's behavior; it is a combination of one or more of the following values.

Value Description
AMMSF_ADDDEFAULTRENDERER Add a default renderer.
AMMSF_CREATEPEER Create a peer stream based on the same object as a pStreamObject.
AMMSF_NOSTALL Run the stream even if Update is not called.
AMMSF_STOPIFNOSAMPLES Terminates the stream if no samples were created or if the last sample is deleted.


[in] Purpose ID for the new media stream.


[in] STREAM_TYPE enumeration value that specifies the new media stream's media type.

Return Values

Returns S_OK if successful or E_POINTER if one or more of the required parameters are invalid.


If dwFlags specifies AMMSF_ADDDEFAULTRENDERER, then the default renderer for the given purpose ID is created, if possible. Currently, the only default renderer supported is for audio using Microsoft® DirectSound®. In this case, the pStreamObject parameter must be NULL and any calls to the IMultiMediaStream::GetMediaStream or IMultiMediaStream::EnumMediaStreams method will not recognize the stream.

If dwFlags specifies AMMSF_CREATEPEER, then a media stream is created using pStreamObject and added to the current multimedia stream. The pStreamObject parameter varies depending on the stream type. In general, pStreamObject can point to an IMediaStream object, in which case a stream with the sample purpose ID and format is created. For IDirectDraw streams, it can also be a pointer to an IDirectDraw interface.

If dwFlags specifies AMMSF_STOPIFNOSAMPLES, then the stream is terminated.

If no flags are set, then pStreamObject can be one of the following.

Value Description
An IAMMediaStream object This stream is then added to the streams in the multimedia stream.
NULL In this case a default IMediaStream object is added to the stream with a default underlying object, if required.
A pointer to an underlying object This is used to construct default streams. For video streams, this can be an IDirectDraw pointer.

See Also