CAPVIDEOCALLBACK callback function (vfw.h)

Article
02/22/2024

The capVideoStreamCallback function is the callback function used with streaming capture to optionally process a frame of captured video. The name capVideoStreamCallback is a placeholder for the application-supplied function name.

To set this callback for streaming capture, send the WM_CAP_SET_CALLBACK_VIDEOSTREAM message to the capture window or call the capSetCallbackOnVideoStream macro.

To set this callback for preview frame capture, send the WM_CAP_SET_CALLBACK_FRAME message to the capture window or call the capSetCallbackOnFrame macro.

Syntax

CAPVIDEOCALLBACK Capvideocallback;

LRESULT Capvideocallback(
  HWND hWnd,
  LPVIDEOHDR lpVHdr
)
{...}

Parameters

hWnd

Handle to the capture window associated with the callback function.

lpVHdr

Pointer to a VIDEOHDR structure containing information about the captured frame.

Return value

None

Remarks

The capture window calls a video stream callback function when a video buffer is marked done by the capture driver. When capturing to disk, this will precede the disk write operation.

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