VIDEO_STREAM_CONFIG_CAPS structure

The VIDEO_STREAM_CONFIG_CAPS structure describes a range of video formats. Video compression and video capture filters use this structure to describe what formats they can produce.

Note   Most of this structure is deprecated, with the exception of the following structure members:
  • guid
  • VideoStandard
  • MinFrameInterval
  • MaxFrameInterval
Applications can use MinFrameInterval and MaxFrameInterval to get the range of supported frame rates from a video capture device. Applications should avoid using any of the other members of this structure. Instead, use the AM_MEDIA_TYPE structure returned by the IAMStreamConfig::GetFormat method.
 

Syntax


typedef struct _VIDEO_STREAM_CONFIG_CAPS {
  GUID     guid;
  ULONG    VideoStandard;
  SIZE     InputSize;
  SIZE     MinCroppingSize;
  SIZE     MaxCroppingSize;
  int      CropGranularityX;
  int      CropGranularityY;
  int      CropAlignX;
  int      CropAlignY;
  SIZE     MinOutputSize;
  SIZE     MaxOutputSize;
  int      OutputGranularityX;
  int      OutputGranularityY;
  int      StretchTapsX;
  int      StretchTapsY;
  int      ShrinkTapsX;
  int      ShrinkTapsY;
  LONGLONG MinFrameInterval;
  LONGLONG MaxFrameInterval;
  LONG     MinBitsPerSecond;
  LONG     MaxBitsPerSecond;
} VIDEO_STREAM_CONFIG_CAPS;

Members

guid

GUID that identifies the format type. For example, FORMAT_VideoInfo or FORMAT_VideoInfo2. For more information, see the formattype member of the AM_MEDIA_TYPE structure.

VideoStandard

The analog video standard supported. The value is a bitwise combination of flags from the AnalogVideoStandard enumeration type, or zero.

InputSize

Native size of the incoming video signal. For a compressor, the size is taken from the input pin. For a capture filter, the size is the largest signal the filter can digitize with every pixel remaining unique.

Note  Deprecated.
 
MinCroppingSize

Smallest source rectangle allowed. The source rectangle is defined in the rcSource member of the VIDEOINFOHEADER or VIDEOINFOHEADER2 structure.

Note  Deprecated.
 
MaxCroppingSize

Largest source rectangle allowed.

Note  Deprecated.
 
CropGranularityX

Horizontal granularity of the source rectangle. This value specifies the increments that are valid between MinCroppingSize and MaxCroppingSize.

Note  Deprecated.
 
CropGranularityY

Vertical granularity of the source rectangle. This value specifies the increments that are valid between MinCroppingSize and MaxCroppingSize.

Note  Deprecated.
 
CropAlignX

Required horizontal alignment of the source rectangle.

Note  Deprecated.
 
CropAlignY

Required vertical alignment of the source rectangle.

Note  Deprecated.
 
MinOutputSize

Minimum output size.

Note  Deprecated.
 
MaxOutputSize

Maximum output size.

Note  Deprecated.
 
OutputGranularityX

Granularity of the output width. This value specifies the increments that are valid between MinOutputSize and MaxOutputSize.

Note  Deprecated.
 
OutputGranularityY

Granularity of output height. This value specifies the increments that are valid between MinOutputSize and MaxOutputSize.

Note  Deprecated.
 
StretchTapsX

Indicates how well the filter can stretch the image horizontally.

Note  Deprecated.
 
StretchTapsY

Indicates how well the filter can stretch the image vertically.

Note  Deprecated.
 
ShrinkTapsX

Indicates how well the filter can shrink the image horizontally.

Note  Deprecated.
 
ShrinkTapsY

Indicates how well the filter can shrink the image vertically.

Note  Deprecated.
 

The previous four structure members use the following values:

ValueMeaning
0

Does not support stretching/shrinking.

1

Uses pixel doubling (stretching) or eliminates pixels (shrinking)

2

Uses interpolation (2 taps)

3 and higher

Uses interpolation (>2 taps)

 

MinFrameInterval

The minimum frame duration, in 100-nanosecond units. This value applies only to capture filters.

MaxFrameInterval

The maximum frame duration, in 100-nanosecond units. This value applies only to capture filters.

MinBitsPerSecond

Minimum data rate this pin can produce.

Note  Deprecated.
 
MaxBitsPerSecond

Maximum data rate this pin can produce.

Note  Deprecated.
 

Remarks

The IAMStreamConfig::GetStreamCaps method returns this structure. An application can use this information to modify the output format on a video compression filter or video capture filter.

For example, assume that filter returns the following values for the source rectangle:

  • MinCroppingSize = (160, 120)
  • MaxCroppingSize = (320, 240)
  • CropGranularityX = 4
  • CropGranularityY = 8
  • CropAlignX = 2
  • CropAlignY = 4

These numbers define the set of rectangles that are valid for the rcSource member of the VIDEOINFOHEADER or VIDEOINFOHEADER2 structure. In this example, the minimum source rectangle is 160 pixels wide x 120 pixels high. The width can be increased in steps of 4 pixels, to a maximum of 320. The height can be increased in steps of 8 pixels, to a maximum of 240. In other words, the valid widths are 160, 164, 168 ... 320; and the valid heights are 120, 128, 136 ... 240.

The CropAlignX and CropAlignY members define where the top-left corner of the source rectangle can sit. For example, the following rectangles are valid, given the previous values:

  • (0, 0, 160, 120)
  • (2, 0, 162, 120)
  • (2, 8, 162, 128)

In a similar way, the MinOutputSize, MaxOutputSize, OutputGranularityX, and OutputGranularityY members define what values are supported for the biWidth and biHeight members of the BITMAPINFOHEADER structure.

For capture filters, the MinFrameInterval and MaxFrameInterval members define the minimum and maximum duration of each frame, as given in the AvgTimePerFrame member of the VIDEOINFOHEADER or VIDEOINFOHEADER2 structure. The filter may not support every frame rate that falls between these two values. The IAMStreamConfig::SetFormat method will set the frame rate to the closest value that the filter supports. If SetFormat succeeds, call IAMStreamConfig::GetFormat to determine the actual frame rate.

Requirements

Header

Strmif.h (include Dshow.h)

See also

DirectShow Structures

 

 

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