IAMMediaStream Interface


The IAMMediaStream interface handles the internal connections between DirectShow filters and filter graphs in applications that use multimedia streaming. This allows applications to automatically negotiate the transfer and conversion of data from the source to the application without having to write code to handle the connection, transfer of data, data conversion, and actual data rendering or file storage. This provides a uniform and predictable method of data access and control.

When to Implement

This interface isn't intended for implementation by application developers.

When to Use

This interface isn't intended for use by application developers.

Methods in Vtable Order
IUnknown methods Description
QueryInterface Retrieves pointers to supported interfaces.
AddRef Increments the reference count.
Release Decrements the reference count.
IAMMediaStream methods Description
Initialize Creates and initializes a new media stream with the specified stream type and purpose ID.
SetState Sets the filter state.
JoinAMMultiMediaStream The IAMMultiMediaStream::AddMediaStream method calls this method, which adds the specified media stream to the current multimedia stream.
JoinFilter Connects a media stream to a media stream filter in the underlying filter graph.
JoinFilterGraph Connects a media stream filter to a filter graph.

IAMMediaStream::Initialize

IAMMediaStream Interface

Creates and initializes a new media stream with the specified stream type and purpose ID.

HRESULT Initialize(
  IUnknown *pSourceObject,
  DWORD dwFlags,
  REFMSPID PurposeID,
  STREAM_TYPE StreamType
  )

Parameters
pSourceObject
[in] Pointer to an IUnknown source object.
dwFlags
[in] Flags. Must be 0.
PurposeID
[in] Purpose ID for the new media stream.
StreamType
[in] A 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.

IAMMediaStream::JoinAMMultiMediaStream

IAMMediaStream Interface

The IAMMultiMediaStream::AddMediaStream method calls this method, which adds the specified media stream to the current multimedia stream.

HRESULT JoinAMMultiMediaStream(
  IAMMultiMediaStream* pAMMultiMediaStream
  )

Parameters
pAMMultiMediaStream
[in] Specifies the IAMMultiMediaStream to add the current media stream to.
Return Values

Returns S_OK if successful or MS_E_SAMPLEALLOC if the media stream already has allocated stream samples.

Remarks

Don't increment the reference count of the supplied multimedia stream as it is already accounted for when created.

This method is not intended to be called by applications.

IAMMediaStream::JoinFilter

IAMMediaStream Interface

Connects a media stream to a media stream filter in the underlying filter graph.

HRESULT JoinFilter( )

Return Values

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

Remarks

Don't increment the reference count for the specified media stream filter.

This method is not intended to be called by applications.

IAMMediaStream::JoinFilterGraph

IAMMediaStream Interface

Connects a media stream filter to a filter graph.

HRESULT JoinFilterGraph(
  IFilterGraph* pGraph
  )

Parameters
pGraph
[in] Indicates the current media stream filter to add to the specified filter graph.
Return Values

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

Remarks

Don't increment the reference count of the specified filter graph.

This method is not intended to be called by applications.

IAMMediaStream::SetState

IAMMediaStream Interface

Sets the filter state.

HRESULT SetState(
  FILTER_STATE State
  )

Parameters
State
[in] Sets the filter's state.
Return Values

Returns S_OK if successful or E_INVALIDARG if the State parameter is invalid..

Remarks

This method is not intended to be called by applications.

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