C#

typedef struct tagBITMAPINFOHEADER { 
  DWORD biSize; 
  LONG biWidth; 
  LONG biHeight; 
  WORD biPlanes; 
  WORD biBitCount 
  DWORD biCompression; 
  DWORD biSizeImage; 
  LONG biXPelsPerMeter; 
  LONG biYPelsPerMeter; 
  DWORD biClrUsed; 
  DWORD biClrImportant; 
} BITMAPINFOHEADER; 

DWORD ICCompress(
    HIC hic,
    DWORD dwFlags,
    LPBITMAPINFOHEADER lpbiOutput,
    LPVOID lpData,
    LPBITMAPINFOHEADER lpbiInput,
    LPVOID lpBits,
    LPDWORD lpckid,
    LPDWORD lpdwFlags,
    LONG lFrameNum,
    DWORD dwFrameSize,
    DWORD dwQuality,
    LPBITMAPINFOHEADER lpbiPrev,
    LPVOID lpPrev
);

[StructLayoutAttribute(LayoutKind.Sequential)]
public struct BITMAPINFOHEADER
{
    public uint biSize;
    public int biWidth;
    public int biHeight;
    public ushort biPlanes;
    public ushort biBitCount;
    public uint biCompression;
    public uint biSizeImage;
    public int biXPelsPerMeter;
    public int biYPelsPerMeter;
    public uint biClrUsed;
    public uint biClrImportant;
}

[DllImport("MSVFW32.dll")]
public static extern int ICCompress(
    IntPtr hic,
    UInt32 dwFlags,        // flags
    ref BITMAPINFOHEADER lpbiOutput,     // output format
    IntPtr lpData,         // output data
    ref BITMAPINFOHEADER lpbiInput,      // format of frame to compress
    IntPtr lpBits,         // frame data to compress
    out UInt32 lpckid,         // ckid for data in AVI file
    out UInt32 lpdwFlags,      // flags in the AVI index.
    int lFrameNum,      // frame number of seq.
    UInt32 dwFrameSize,    // reqested size in bytes. (if non zero)
    UInt32 dwQuality,      // quality within one frame
    IntPtr lpbiPrev,       // format of previous frame
    IntPtr lpPrev          // previous frame
    );

// Setup compressor
compressorHnd = Avi.ICOpen(Avi.FOURCC.ICTYPE_VIDEO, Avi.FOURCC.mmioFOURCC('L','E','A','D'), Avi.ICMODE.ICMODE_COMPRESS);

outbi = new Avi.BITMAPINFOHEADER();
inbi = new Avi.BITMAPINFOHEADER();

outbi.biSize = Convert.ToUInt32(Marshal.SizeOf(outbi)); // 40
outbi.biBitCount = 24;
outbi.biWidth = 640;
outbi.biHeight = 480;
outbi.biPlanes = 1;
outbi.biBitCount = 24;
outbi.biCompression = 0;

inbi.biSize = Convert.ToUInt32(Marshal.SizeOf(inbi));
inbi.biWidth = width;
inbi.biHeight = height;
inbi.biPlanes = 1;
inbi.biBitCount = Convert.ToUInt16(countBitsPerPixel);

byte[] outImgData = new byte[(outbi.biHeight * outbi.biWidth * (outbi.biBitCount / 8))];
GCHandle outImgHnd = GCHandle.Alloc(outImgData, GCHandleType.Pinned);

UInt32 lpckid = new Int32();
UInt32 lpdwflags = new Int32();

int i = Avi.ICCompress(compressorHnd,
                    0,
                    ref outbi,
                    outImgHnd.AddrOfPinnedObject(),
                    ref inbi,
                    inBmpDat.Scan0,
                    out lpckid,
                    out lpdwflags,
                    frameNum,
                    0,
                    5000,
                    IntPtr.Zero,
                    IntPtr.Zero);