KS_VIDEO_STREAM_CONFIG_CAPS structure (ksmedia.h)
The KS_VIDEO_STREAM_CONFIG_CAPS structure describes the configuration and capabilities of a video stream, including analog video standard (for example, NTSC, PAL or SECAM), scaling, and cropping capabilities; minimum and maximum frame rates; and minimum and maximum data rates.
Syntax
typedef struct _KS_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;
} KS_VIDEO_STREAM_CONFIG_CAPS, *PKS_VIDEO_STREAM_CONFIG_CAPS;
Members
guid
GUID that specifies the video format type. Possible values include:
KSDATAFORMAT_SPECIFIER_VIDEOINFO
KSDATAFORMAT_SPECIFIER_VIDEOINFO2
KSDATAFORMAT_SPECIFIER_ANALOGVIDEO
KSDATAFORMAT_SPECIFIER_VBI
KSDATAFORMAT_SPECIFIER_MPEG1_VIDEO
KSDATAFORMAT_SPECIFIER_MPEG2_VIDEO
This GUID is identical to the DirectShow AM_MEDIA_TYPE enumeration. For more information about AM_MEDIA_TYPE, see the DirectX SDK documentation.
VideoStandard
Specifies the analog video standards that are supported by the stream. This member can be set to one or more (logically ORed) values from the KS_AnalogVideoStandard enumeration.
InputSize
Specifies the size of the incoming signal. InputSize indicates the image rectangle's width and height, in pixels. This is the largest signal that the filter can digitize with each pixel remaining unique.
MinCroppingSize
Specifies the smallest cropping rectangle allowed, as specified in the rcSource member of the KS_VIDEOINFOHEADER structure, which is associated with the DataRange member.
MaxCroppingSize
Specifies the largest cropping rectangle allowed, as specified in the rcSource member of the KS_VIDEOINFOHEADER structure, which is associated with the DataRange member.
CropGranularityX
Specifies the horizontal granularity of the cropping size. For example, valid widths could be specified as even multiples of four.
CropGranularityY
Specifies the vertical granularity of the cropping size. For example, valid heights could be specified as even multiples of four.
CropAlignX
Specifies the horizontal alignment of the cropping rectangle inside InputSize. For example, the minidriver could specify that valid rectangles must start on a boundary that is a multiple of four.
CropAlignY
Specifies the vertical alignment of the cropping rectangle inside InputSize. For example, the minidriver could specify that valid rectangles must start on a boundary that is a multiple of four.
MinOutputSize
Specifies the smallest bitmap that this pin can produce.
MaxOutputSize
Specifies the largest bitmap that this pin can produce.
OutputGranularityX
Specifies the granularity of the output bitmap width.
OutputGranularityY
Specifies the granularity of the output bitmap height.
StretchTapsX
Specifies one of the following values to indicate how well the filter can stretch the image's width.
| Value | Meaning |
|---|---|
| 0 | The filter cannot stretch. |
| 1 | The filter uses pixel doubling to achieve stretching. |
| 2 | The filter uses interpolation (2 taps). |
| 3 | The filter uses a higher-order (smoother) form of interpolation. |
StretchTapsY
Specifies one of the following values to indicate how well the filter can stretch the image's height.
| Value | Meaning |
|---|---|
| 0 | The filter cannot stretch. |
| 1 | The filter uses pixel doubling to achieve stretching. |
| 2 | The filter uses interpolation (2 taps). |
| 3 | The filter uses a higher-order (smoother) form of interpolation. |
ShrinkTapsX
Specifies one of the following values to indicate how well the filter can shrink the image's width.
| Value | Meaning |
|---|---|
| 0 | The filter cannot shrink. |
| 1 | The filter eliminates some rows of pixels to achieve shrinking. |
| 2 | The filter uses interpolation (2 taps). |
| 3 | The filter uses a higher-order (smoother) form of interpolation. |
ShrinkTapsY
Specifies one of the following values to indicate how well the filter can shrink the image's height.
| Value | Meaning |
|---|---|
| 0 | The filter cannot shrink. |
| 1 | The filter eliminates some columns of pixels to achieve shrinking. |
| 2 | The filter uses interpolation (2 taps). |
| 3 | The filter uses a higher-order (smoother) form of interpolation. |
MinFrameInterval
Specifies the minimum frame rate allowed. This value applies to capture filters only.
MaxFrameInterval
Specifies the maximum frame rate allowed. This value applies to capture filters only.
MinBitsPerSecond
Specifies the minimum data rate, in bits per second, that this pin can produce.
MaxBitsPerSecond
Specifies the maximum data rate, in bits per second, that this pin can produce.
Remarks
The KS_VIDEO_STREAM_CONFIG_CAPS structure is identical to the DirectShow VIDEO_STREAM_CONFIG_CAPS structure.
It is important to understand the relationships between the members of this structure. For example, assume the following values for some of the structure members:
MinCroppingSize = (160, 120)
MaxCroppingSize = (320, 240)
CropGranularityX = 4
CropGranularityY = 8
These values indicate that valid cropping sizes begin at MinCroppingSize and increase in steps in the x-direction by CropGranularityX and in the y-direction by CropGranularityY. In this case, the x-value can be anywhere from 160 to 320 pixels, in steps of four, and the y-value can be anywhere from 120 to 240 pixels in steps of eight.
In the example scenario, a few of the valid sizes are:
160 × 120, 164 × 120, 168 × 120, 172 × 120, and so on.
160 × 128, 164 × 128, 168 × 128, 172 × 128, and so on.
160 × 136, 164 × 136, 168 × 136, 172 × 136, and so on.
CropAlignX and CropAlignY indicate where the cropping rectangle can be located inside the input size rectangle. Given a 160 × 120 cropping rectangle and a value of 2 for CropAlignX and a value of 4 for CropAlignY, some of the valid values for the rcSource member of the KS_VIDEOINFOHEADER structure would be:
(0, 0, 160, 120)
(2, 0, 162, 120)
(2, 4, 162, 124)
(2, 8, 162, 128)
For a 320 × 240 cropping rectangle and the same cropping alignment values, (2, 4, 322, 244) is one example of the many valid rectangles.
The MinCroppingSize, MaxCroppingSize, CropGranularityX, CropGranularityY, CropAlignX, and CropAlignY members discussed above work together to specify which values of rcSource are valid for the KS_VIDEOINFOHEADER structure that describes the output pin's media type. The remaining structure members (MinOutputSize, MaxOutputSize, OutputGranularityX, and OutputGranularityY) describe the biWidth and biHeight members of the KS_BITMAPINFOHEADER structure, which is contained in the pin's media type KS_VIDEOINFOHEADER structure.
Requirements
| Requirement | Value |
|---|---|
| Header | ksmedia.h (include Ksmedia.h) |