ICDrawBegin function (vfw.h)

Article
10/05/2021

The ICDrawBegin function initializes the renderer and prepares the drawing destination for drawing.

Syntax

DWORD VFWAPIV ICDrawBegin(
  HIC                hic,
  DWORD              dwFlags,
  HPALETTE           hpal,
  HWND               hwnd,
  HDC                hdc,
  int                xDst,
  int                yDst,
  int                dxDst,
  int                dyDst,
  LPBITMAPINFOHEADER lpbi,
  int                xSrc,
  int                ySrc,
  int                dxSrc,
  int                dySrc,
  DWORD              dwRate,
  DWORD              dwScale
);

Parameters

hic

Handle to the decompressor to use.

dwFlags

Decompression flags. The following values are defined.

Value	Meaning
ICDRAW_ANIMATE	Application can animate the palette.
ICDRAW_CONTINUE	Drawing is a continuation of the previous frame.
ICDRAW_FULLSCREEN	Draws the decompressed data on the full screen.
ICDRAW_HDC	Draws the decompressed data to a window or a DC.
ICDRAW_MEMORYDC	DC is off-screen.
ICDRAW_QUERY	Determines if the decompressor can decompress the data. The driver does not decompress the data.
ICDRAW_UPDATING	Current frame is being updated rather than played.

hpal

Handle to the palette used for drawing.

hwnd

Handle to the window used for drawing.

hdc

DC used for drawing.

xDst

The x-coordinate of the upper right corner of the destination rectangle.

yDst

The y-coordinate of the upper right corner of the destination rectangle.

dxDst

Width of the destination rectangle.

dyDst

Height of the destination rectangle.

lpbi

Pointer to a BITMAPINFOHEADER structure containing the format of the input data to be decompressed.

xSrc

The x-coordinate of the upper right corner of the source rectangle.

ySrc

The y-coordinate of the upper right corner of the source rectangle.

dxSrc

Width of the source rectangle.

dySrc

Height of the source rectangle.

dwRate

Frame rate numerator. The frame rate, in frames per second, is obtained by dividing dwRate by dwScale.

dwScale

Frame rate denominator. The frame rate, in frames per second, is obtained by dividing dwRate by dwScale.

Return value

Returns ICERR_OK if the renderer can decompress the data or ICERR_UNSUPPORTED otherwise.

Remarks

The ICDRAW_HDC and ICDRAW_FULLSCREEN flags are mutually exclusive. If an application sets the ICDRAW_HDC flag in dwFlags, the decompressor uses hwnd, hdc, and the parameters defining the destination rectangle (xDst, yDst, dxDst, and dyDst). Your application should set these parameters to the size of the destination rectangle. Specify destination rectangle values relative to the current window or DC.

If an application sets the ICDRAW_FULLSCREEN flag in dwFlags, the hwnd and hdc parameters are not used and should be set to NULL. Also, the destination rectangle is not used and its parameters can be set to zero.

The source rectangle is relative to the full video frame. The portion of the video frame specified by the source rectangle is stretched or shrunk to fit the destination rectangle.

The dwRate and dwScale parameters specify the decompression rate. The integer value specified for dwRate divided by the integer value specified for dwScale defines the frame rate in frames per second. This value is used by the renderer when it is responsible for timing frames during playback.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	vfw.h
Library	Vfw32.lib
DLL	Msvfw32.dll