ICDecompressBegin macro (vfw.h)

Article
02/22/2024

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.

Syntax

void 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 value

None

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

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