About Kernel Streaming Debug

I have tried to use Kernel Stream Extensions for kernel streaming debugging,
and just tried “!ks.allstreams” “!ks.enumdevobj” and “!ks.objhdr” extension
command but just gotten following error return:

0: kd> !ks.allstreams
2 Kernel Streaming FDOs found:
Functional Device 81301920 [\Driver\MYCAM]
Functional Device 81f5e358 [\Driver\MSPQM]
0: kd> !ks.enumdevobj 81301920
81301920: this is **NOT** a recognized KS device object!

Can anyone tell me why did I get this error return message? I believe
0x81301920 is the FDO of \Driver\MYCAM.
By the way, can anyone tell me how to obtain the PIN or FILTER object
pointers which are instantiated in \Driver\MYCAM device driver.