ICDecompressEx function (vfw.h)

Article
02/22/2024

The ICDecompressEx function decompresses a single video frame.

Syntax

LRESULT VFWAPI_INLINE ICDecompressEx(
  HIC                hic,
  DWORD              dwFlags,
  LPBITMAPINFOHEADER lpbiSrc,
  LPVOID             lpSrc,
  int                xSrc,
  int                ySrc,
  int                dxSrc,
  int                dySrc,
  LPBITMAPINFOHEADER lpbiDst,
  LPVOID             lpDst,
  int                xDst,
  int                yDst,
  int                dxDst,
  int                dyDst
);

Parameters

hic

Handle to the decompressor.

dwFlags

Decompression flags. The following values are defined.

Value	Meaning
ICDECOMPRESS_HURRYUP	Tries to decompress at a faster rate. When an application uses this flag, the driver should buffer the decompressed data but not draw the image.
ICDECOMPRESS_NOTKEYFRAME	Current frame is not a key frame.
ICDECOMPRESS_NULLFRAME	Current frame does not contain data and the decompressed image should be left the same.
ICDECOMPRESS_PREROLL	Current frame precedes the point in the movie where playback starts and, therefore, will not be drawn.
ICDECOMPRESS_UPDATE	Screen is being updated or refreshed.

lpbiSrc

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

lpSrc

Pointer to the input data.

xSrc

The x-coordinate of the source rectangle for the DIB specified by lpbiSrc.

ySrc

The y-coordinate of the source rectangle for the DIB specified by lpbiSrc.

dxSrc

Width of the source rectangle.

dySrc

Height of the source rectangle.

lpbiDst

Pointer to a BITMAPINFOHEADER structure containing the output format.

lpDst

Pointer to a buffer that is large enough to contain the decompressed data.

xDst

The x-coordinate of the destination rectangle for the DIB specified by lpbiDst.

yDst

The y-coordinate of the destination rectangle for the DIB specified by lpbiDst.

dxDst

Width of the destination rectangle.

dyDst

Height of the destination rectangle.

Return value

Returns ICERR_OK if successful or an error otherwise.

Remarks

Typically, applications use the ICDECOMPRESS_PREROLL flag to seek to a key frame in a compressed stream. The flag is sent with the key frame and with subsequent frames required to decompress the desired frame.

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