IRenderEngine::ConnectFrontEnd method

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

Note

[Deprecated. This API may be removed from future releases of Windows.]

 

The ConnectFrontEnd method builds the front end of the filter graph from the current timeline.

Syntax

HRESULT ConnectFrontEnd();

Parameters

This method has no parameters.

Return value

Returns an HRESULT value. Possible return values include the following:

Return code	Description
S_OK	Success.
S_WARN_OUTPUTRESET	Rendering portion of the graph was deleted.
E_INVALIDARG	No timeline set for this render engine.
E_MUST_INIT_RENDERER	Render engine failed to initialize.
E_RENDER_ENGINE_IS_BROKEN	Operation failed because the project was not rendered successfully.
E_UNEXPECTED	Unexpected error.
VFW_E_INVALIDMEDIATYPE	Invalid media type.

 

Remarks

This method does not build the rendering portion of the filter graph. The application must connect the output pins on the front end to the desired rendering filters:

• To preview, call the IRenderEngine::RenderOutputPins method.
• To output a file, call IRenderEngine::GetGroupOutputPin to retrieve the output pin for each group, then connect the pins to a multiplexer filter.

If you are using the basic render engine, the output pins on the front end produce uncompressed data. If you are using the smart render engine, the output pins produce compressed data.

If you change the timeline after you build the filter graph, you must call ConnectFrontEnd again to rebuild the front end. The method preserves the rendering portion of the graph whenever possible. However, if you add or delete a group, or change the order of the groups, ConnectFrontEnd deletes the rendering portion and your application must rebuild it. If the method deletes the rendering portion, it returns S_WARN_OUTPUTRESET.

Note

The header file Qedit.h is not compatible with Direct3D headers later than version 7.

 

Note

To obtain Qedit.h, download the Microsoft Windows SDK Update for Windows Vista and .NET Framework 3.0. Qedit.h is not available in the Microsoft Windows SDK for Windows 7 and .NET Framework 3.5 Service Pack 1.

 

Requirements

Requirement	Value
Header	Qedit.h
Library	Strmiids.lib

See also

IRenderEngine Interface

Error and Success Codes