TZStreamRec = packed record
  next_in: PChar;
  avail_in: Integer;
  total_in: Longint;
  next_out: PChar;
  avail_out: Integer;
  total_out: Longint;
  msg: PChar;
  internal: Pointer;
  zalloc: TAlloc;
  zfree: TFree;
  AppData: Pointer;
  data_type: Integer;
  adler: Longint;
  reserved: Longint;
end;