ICDecompressBegin

The ICDecompressBegin macro notifies a video decompression driver to prepare to decompress data. You can use this macro or explicitly call the ICM_DECOMPRESS_BEGIN message.

DWORD ICDecompressBegin(
 hic,          lpbiInput,   lpbiOutput  );

Parameters

hic

Handle to a decompressor.

lpbiInput

Pointer to a BITMAPINFO structure containing the input format.

lpbiOutput

Pointer to a BITMAPINFO structure containing the output format.

Return Values

Returns ICERR_OK if the specified decompression is supported or ICERR_BADFORMAT otherwise.

Remarks

When the driver receives this message, it should allocate buffers and do any time-consuming operations so that it can process ICM_DECOMPRESS messages efficiently.

The ICDecompressBegin and ICDecompressEnd macros do not nest. If your driver receives ICM_DECOMPRESS_BEGIN before decompression is stopped with ICM_DECOMPRESS_END, it should restart decompression with new parameters.

Requirements

**  Windows NT/2000/XP:** Included in Windows NT 3.1 and later.
**  Windows 95/98/Me:** Included in Windows 95 and later.
**  Header:** Declared in Vfw.h.

See Also

Video Compression Manager, Video Compression Macros, BITMAPINFO, ICDecompressEnd, ICM_DECOMPRESS, ICM_DECOMPRESS_BEGIN, ICM_DECOMPRESS_END