Please help me, how I can do this in delphi? thanks.
struct x { uint32 a : 32; unsigned int b : 20; unsigned int c : 4; };
that struct uses a C feature called bitfields where integers can have widths of fractional bytes. bitfields are not available in Delphi, see this answers to this question for details of how to do it using an object
How to simulate bit-fields in Delphi records?