The ICM_COMPRESS_GET_SIZE message requests that the video compression driver supply the maximum size of one frame of data when compressed into the specified output format. You can send this message explicitly or by using the ICCompressGetSize macro.
ICM_COMPRESS_GET_SIZE
wParam = (DWORD) (LPVOID) lpbiInput;
lParam = (DWORD) (LPVOID) lpbiOutput;
Returns the maximum number of bytes a single compressed frame can occupy.
Typically, applications send this message to determine how large a buffer to allocate for the compressed frame.
The driver should calculate the size of the largest possible frame based on the input and output formats.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in vfw.h.
Video Compression Manager Overview, Video Compression Messages, BITMAPINFO, ICCompressGetSize