What is RIDI_PREPARSEDDATA in GetRawInputDeviceInfo?

Windows API function GetRawInputDeviceInfo has a parameter uiCommand. One of the options is RIDI_PREPARSEDDATA. It says "pData points 开发者_StackOverflowto the previously parsed data".

I don't get what previously parsed data they are referring to. Is it the data that was last sent with WM_INPUT? Or is it data that was returned by any of the functions? Or something else? Also in what format is that data?

Preparsed data is report descriptor data associated with a top-level collection. User-mode applications or kernel-mode drivers use preparsed data to extract information about specific HID controls without having to obtain and interpret a device's entire report descriptor.

MSDN Link

"Also in what format is that data?"

Today I looked into GetRawInputDeviceInfo(), including the RIDI_PREPARSEDDATA data. Here's the output of the program when I test my XBOX controller. Everything except for displayable characters are in hex, and the hex for the displayable characters are given in parentheses after the displayable character.

getting device info...
Preparing 5 device lists...
Getting 5 devices...
index: type|    location
0: HID| 0x01FB035F
1: Keyboard|    0x0001003F
2: Keyboard|    0x000B003D
3: Mouse|   0x0001003B
4: Mouse|   0x000B0039

Which would you like more info about?__

Pointer: 0x01FB035F
Type: HID
Name: \\?\HID#VID_0E6F&PID_0401&IG_00#7&2c93b906&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}
Vendor ID: 0x00000e6f
Product ID: 0x00000401
Version Number: 0x00000000
Usage Page: 0x0001
Usage: 0x0005

DATA: (940 bytes)
H(0x48) i(0x69) d(0x64) P(0x50)
 (0x20) K(0x4b) D(0x44) R(0x52)
05 00 01 00
00 00 00 00
00 00 07 00
07 00 0f 00
07 00 00 00
07 00 00 00
07 00 00 00
07 00 00 00
d8 02 04 00
01 00 00 00
10 00 01 00
03 00 10 00
02 00 00 00
05 00 01 00
01 00 00 00
08 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
1(0x31) 00 1(0x31) 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
ff ff ff ff
00 00 00 00
ff ff ff ff
00 00 00 00
00 00 00 00
01 00 00 00
10 00 01 00
01 00 10 00
02 00 00 00
03 00 01 00
01 00 00 00
08 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
0(0x30) 00 0(0x30) 00
00 00 00 00
00 00 00 00
01 00 01 00
00 00 00 00
00 00 00 00
ff ff ff ff
00 00 00 00
ff ff ff ff
00 00 00 00
00 00 00 00
01 00 00 00
10 00 01 00
07 00 10 00
02 00 00 00
09 00 02 00
01 00 00 00
08 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
4(0x34) 00 4(0x34) 00
00 00 00 00
00 00 00 00
02 00 02 00
00 00 00 00
00 00 00 00
ff ff ff ff
00 00 00 00
ff ff ff ff
00 00 00 00
00 00 00 00
01 00 00 00
10 00 01 00
05 00 10 00
02 00 00 00
07 00 02 00
01 00 00 00
08 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
3(0x33) 00 3(0x33) 00
00 00 00 00
00 00 00 00
03 00 03 00
00 00 00 00
00 00 00 00
ff ff ff ff
00 00 00 00
ff ff ff ff
00 00 00 00
00 00 00 00
01 00 00 00
10 00 01 00
09 00 10 00
02 00 00 00
0b 00 03 00
01 00 00 00
08 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
2(0x32) 00 2(0x32) 00
00 00 00 00
00 00 00 00
04 00 04 00
00 00 00 00
00 00 00 00
ff ff ff ff
00 00 00 00
ff ff ff ff
00 00 00 00
00 00 00 00
09 00 00 00
01 00 0a 00
0b 00 0a 00
02 00 00 00
0d 00 00 00
01 00 05 00
1c 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
01 00 0a 00
00 00 00 00
00 00 00 00
05 00 0e 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
01 00 00 02
04 00 01 00
0c 00 04 00
B(0x42) 00 00 00
0d 00 00 00
01 00 05 00
08 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
9(0x39) 00 9(0x39) 00
00 00 00 00
00 00 00 00
0f 00 0f 00
01 00 00 00
01 00 00 00
08 00 00 00
00 00 00 00
;(0x3b) 10 00 00
0e 00 00 00
00 00 00 00
05 00 01 00
00 00 03 00
00 00 03 00
01 00 00 00
00 00 01 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 01 00
00 00 00 00
01 00 00 00
00 00 00 00
00 00 01 00
00 00 00 00
02 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
00 00 00 00
end of data.Press any key to continue . . . 

Notice the HidP KDR at the beginning. Other than that it looks like gibberish. The program formatted it nicely into four-octet words, but it looks like it will not display properly here without extra effort from me. Yes, it is meant to display on a command line, and no, I do not want to get rid of the result of system("pause").