Compressing Data

The following example compresses image data for use in an AVI file. It assumes the compressor does not support the VIDCF_CRUNCH or VIDCF_TEMPORAL flags, but it does support VIDCF_QUALITY. The example uses the ICCompressBegin macro, the ICCompress function, and the ICCompressEnd macro.



DWORD dwCkID; 
DWORD dwCompFlags; 
DWORD dwQuality; 
LONG  lNumFrames, lFrameNum; 
// Assume dwNumFrames is initialized to the total number of frames. 
// Assume dwQuality holds the proper quality value (0-10000). 
// Assume lpbiOut, lpOut, lpbiIn, and lpIn are initialized properly. 
 
// If OK to start, compress each frame. 
if (ICCompressBegin(hIC, lpbiIn, lpbiOut) == ICERR_OK)
{ 
    for ( lFrameNum = 0; lFrameNum < lNumFrames; lFrameNum++)
    { 
        if (ICCompress(hIC, 0, lpbiOut, lpOut, lpbiIn, lpIn, 
            &dwCkID, &dwCompFlags, lFrameNum, 
            0, dwQuality, NULL, NULL) == ICERR_OK)
        { 
            // Write compressed data to the AVI file. 
             
            // Set lpIn to the next frame in the sequence. 
             
        } 
        else 
        { 
            // Handle compressor error. 
        } 
    } 
    ICCompressEnd(hIC);    // terminate compression 
} 
else 
{ 
    // Handle the error identifying the unsupported format. 
} 
 


 

 

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