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Determining a Decompressor's Output Format

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[The feature associated with this page, Video Compression Manager, is a legacy feature. Microsoft strongly recommends that new code does not use this feature.]

The following example determines the buffer size needed for the data specifying the decompression format using the ICDecompressGetFormatSize macro, allocates a buffer of the appropriate size using the GlobalAlloc function, and retrieves the decompression format information using the ICDecompressGetFormat macro.

LPBITMAPINFOHEADER lpbiIn, lpbiOut; 
 
// Assume *lpbiIn points to the input (compressed) format. 
dwFormatSize = ICDecompressGetFormatSize(hIC, lpbiIn); 
h = GlobalAlloc(GHND, dwFormatSize); 
lpbiOut = (LPBITMAPINFOHEADER)GlobalLock(h); 
ICDecompressGetFormat(hIC, lpbiIn, lpbiOut);

The following example shows how an application can use the ICDecompressQuery macro to determine if a decompressor can handle the input and output formats.

LPBITMAPINFOHEADER lpbiIn, lpbiOut; 
// Assume *lpbiIn & *lpbiOut are initialized to the respective 
// formats.
 
if (ICDecompressQuery(hIC, lpbiIn, lpbiOut) == ICERR_OK)
{ 
    
    // Format is supported - use the decompressor. 
    
}

The following code fragment shows how to get the palette information using the ICDecompressGetPalette macro.

ICDecompressGetPalette(hIC, lpbiIn, lpbiOut); 
 
// Move up to the palette. 
lpPalette = (LPBYTE)lpbiOut + lpbi->biSize;