IBaseFilter Interface (Windows CE 5.0)

Windows CE 5.0
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This interface abstracts an object that has typed input and output connections and can be aggregated dynamically.

All DirectShow filters expose this interface.

Because the IBaseFilter interface derives from the IMediaFilter interface, it inherits IPersist.

When to Implement

Implement this interface on every DirectShow filter. It is recommended that you use the CBaseFilter class library to implement this interface.

When to Use

The filter graph manager is the primary user of this interface.

Applications or other filters can use IBaseFilter methods directly to enumerate or retrieve pins or to get vendor information, but should not use any methods derived from IMediaFilter to control media streaming (use the IMediaControl methods on the filter graph manager instead).

Methods in Vtable Order

The following tables show the methods that appear in the Vtable beneath the standard COM methods inherited from IUnknown.

IMediaFilter methodDescription
StopInforms the filter to transition to the new (stopped) state.
PauseInforms the filter to transition to the new (paused) state.
RunInforms the filter to transition to the new (running) state.
GetStateDetermines the state of the filter.
SetSyncSourceIdentifies the reference clock to which the filter should synchronize activity.
GetSyncSourceRetrieves the current reference clock (or NULL if there is no clock).

Passes a time value to synchronize independent streams.

IBaseFilter methodDescription
EnumPinsEnumerates the specified pins available on this filter.
FindPinRetrieves a pointer to the pin with the specified identifier.
QueryFilterInfoRetrieves information about the specified filter.
JoinFilterGraphNotifies a filter that it has joined a filter graph.
QueryVendorInfoRetrieves optional information supplied by a vendor for the specified filter.


DirectShow applications and DirectShow filters have different include file and link library requirements.

For more information, see Setting Up the Build Environment.

OS Versions: Windows CE 2.12 and later. Version 2.12 requires DXPAK 1.0 or later.

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