ICDraw function (vfw.h)

Article
02/22/2024

The ICDraw function decompresses an image for drawing.

Syntax

DWORD VFWAPIV ICDraw(
  HIC    hic,
  DWORD  dwFlags,
  LPVOID lpFormat,
  LPVOID lpData,
  DWORD  cbData,
  LONG   lTime
);

Parameters

hic

Handle to a decompressor.

dwFlags

Decompression flags. The following values are defined.

Value	Meaning
ICDRAW_HURRYUP	Data is buffered and not drawn to the screen. Use this flag for fastest decompression.
ICDRAW_NOTKEYFRAME	Current frame is not a key frame.
ICDRAW_NULLFRAME	Current frame does not contain any data and the previous frame should be redrawn.
ICDRAW_PREROLL	Current frame of video occurs before playback should start. For example, if playback will begin on frame 10, and frame 0 is the nearest previous key frame, frames 0 through 9 are sent to the driver with the ICDRAW_PREROLL flag set. The driver needs this data to display frame 10 properly.
ICDRAW_UPDATE	Updates the screen based on previously received data. Set lpData to NULL when this flag is used.

lpFormat

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

lpData

Pointer to the input data.

cbData

Size of the input data, in bytes.

lTime

Time, in samples, to draw this frame. The units for video data are frames. For a definition of the playback rate, see the dwRate and dwScale members of the ICDRAWBEGIN structure.

Return value

Returns ICERR_OK if successful or an error otherwise.

Remarks

You can initiate drawing the frames by sending the ICM_DRAW_START message (or by using the ICDrawStart macro). The application should be sure to buffer the required number of frames before drawing is started. Send the KM_GETBUFFERSWANTED message (or use the ICGetBuffersWanted macro) to obtain this value.

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