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KS_ANALOGVIDEOINFO structure (ksmedia.h)

  • Article

The KS_ANALOGVIDEOINFO structure describes an analog video stream.

Syntax

typedef struct tagKS_AnalogVideoInfo {
  RECT           rcSource;
  RECT           rcTarget;
  DWORD          dwActiveWidth;
  DWORD          dwActiveHeight;
  REFERENCE_TIME AvgTimePerFrame;
} KS_ANALOGVIDEOINFO, *PKS_ANALOGVIDEOINFO;

Members

rcSource

Specifies a clipping rectangle that selects the portion of the active video signal to use.

rcTarget

Specifies a rectangle that indicates which part of the target buffer to use.

dwActiveWidth

Specifies the width of the active incoming video signal. For example, the value for ITUR-601 could be set to 720 active samples per line.

dwActiveHeight

Specifies the height of the active incoming video signal. For example, the value for NTSC could be set to 483. For PAL/SECAM, the value could be set to 575.

AvgTimePerFrame

Specifies the average time per frame, in 100-nanosecond units.

Remarks

A source filter can request that the sink filter take only a section of the video by providing values that effectively define a clipping rectangle in the rcSource member. However, if the sink filter does not check for the clipping rectangle on connection, the sink filter simply renders all of the video, effectively ignoring any clipping information passed from the source filter to the sink filter.

Ideally, a sink filter checks rcSource. If the sink filter does not support image extraction, and the rectangle is not empty, then it rejects the connection. A filter should use the Win32 function SetRectEmpty to reset a rectangle to all zeros (and set IsRectEmpty to later check the rectangle).

The rcTarget member specifies the destination rectangle for the video. Most source filters set this member to all zeros. A downstream filter can request that the video be placed in a particular area of the buffers it supplies. In this case, it calls the Win32 function QueryAccept with a nonempty target.

Requirements

Requirement Value
Header ksmedia.h (include Ksmedia.h)