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Filters Used with the Video Capture Devices

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Microsoft DirectShow is the common client for video capture minidrivers. User-mode DirectShow filters expose the capabilities contained in the video capture minidriver to user-mode applications.

Microsoft provides four DirectShow filters that work with Stream class minidrivers to expose the underlying video capture minidriver functionality:

Filter functionality Property sets supported by kernel streaming Purpose DLL DirectShow interfaces exposed

Video capture

PROPSETID_VIDCAP_DROPPEDFRAMES

PROPSETID_VIDCAP_VIDEOCOMPRESSION

PROPSETID_VIDCAP_VIDEOCONTROL

PROPSETID_VIDCAP_VIDEODECODER

PROPSETID_VIDCAP_CAMERAMCONTROL

PROPSETID_VIDCAP_VIDEOPROCAMP

Provides output streams of digital video data and ancillary data streams.

KsProxy.ax

IAMAnalogVideoDecoder

IAMCameraControl

IAMVideoProcAmp

IAMDroppedFrames

IAMStreamConfig

IAMVideoControl

IAMVideoCompression

IAMBufferNegotiation

TV tuning

PROPSETID_TUNER

Provides tuning control of analog TV, digital TV, FM and AM tuners.

KsTvTune.ax

IAMTVTuner

TV audio

PROPSETID_VIDCAP_TVAUDIO

Provides control of TV audio such as SAP selection.

KsXBar.ax

IAMTVAudio

Crossbar

PROPSETID_VIDCAP_CROSSBAR

Provides routing of video and audio streams.

KsXBar.ax

IAMCrossbar

Each of these filters, and the functionality they expose (video capture, TV/radio tuning, TV audio and crossbar) appears in a filter graph as a separate filter exposing unique interfaces.

For more information about the DirectShow interfaces listed in the table above, see the DirectShow Software Development Kit (SDK). The DirectShow SDK documentation also includes a sample application (AMCAP) that demonstrates how to construct the full range of both WDM and VfW capture graphs.