GetSequencePointer (DVR version only)

Description

Returns the pointer to the pixel at the specified coordinates of the selected frame in the memory sequence.


Syntax

[VB]
Value=objActiveGige.GetSequencePointer( Frame, X, Y )

[C/C++]
HRESULT GetSequencePointer( long iFrame, short X, short Y, VARIANT* pValue );


Data Types [VB]

Frame: Long
X: Integer
Y: Integer
Return value: Variant (pointer)


Parameters [C/C++]

iFrame [in]

The zero-based index of the frame in the memory sequence

X [in]

The x-coordinate of the pixel

Y [in]

The y-coordinate of the pixel

pValue [out,retval]

Pointer to the variant containing the pointer to the specified memory location

Return Values

S_OK

Success

E_FAIL

Failure.

E_INVALIDARG

Invalid input arguments.

Example

This C++ example grabs a frame, retrieves a pointer to the 32th line in the frame # 7 of the memory sequence and copies the pixels values into a byte array . A wrapper class CActiveGige is used to access the ActiveGige control:

BYTE line[4096];
int iWidth=m_ActiveGige.GetSizeX;
int iHeight=m_ActiveGige.GetSizeY;
VARIANT v=m_ActiveGige.GetSequencePointer(7,0,iHeight-1-32);
memcpy(&line,v.pcVal,iWidth);

Remarks

The GetSequencePointer method provides the most efficient way to quickly access the memory sequence data in pointer-aware programming languages. The number of bytes in each line of the image buffer depends on the format and horizontal size of the video as specified in the following table:

Camera Pixel Format	Output Format	Line width in bytes
Mono8	8-bit monochrome	SizeX
Mono10, Mono12, Mono16	16-bit monochrome	SizeX * 2
YUV411, YUV422, YUV444, RGB8, BGR8, Bayer8	24-bit RGB	SizeX * 3
RGB10, RGB12, RGB16, BGR10, BGR12, Bayer10, Bayer12, Bayer16	48-bit RGB	SizeX * 6

Note that this method automatically converts the raw sequence data into standard monochrome or RGB output formats. To access the raw image data, use GetSequenceRawData.

Images in ActiveGige are stored bottom up, therefore the zero vertical coordinate corresponds to the bottom line of the image.

The values of the x and y coordinates must not exceed the width and height of the video frame, or the error will occur.