How to decode SDP file?

[dbq_kd]

Hi all,

I have some SDP file for streaming that contains some encoded information. I'm trying to decode the SDP file. Do you know what kind of method was used to encode the information in profile-level-id and sprop-parameter-sets

v=0
o=- 571622436 4192730712 IN IP4 192.168.0.189
s=XXX
i=RTP Streaming
u=XXX
e=XXXX
c=IN IP4 192.168.0.138/64
m=video 8000 RTP/AVP 97
a=rtpmap:97 H264/90000
a=control:trackID=1
a=fmtp:97 profile-level-id=421e00; packetization-mode=1; sprop-parameter-sets=Z0LgHtoC0P5A,aM4zyA==
m=audio 6666 RTP/AVP 96
a=rtpmap:96 mpeg4-generic/48000/2
a=control:trackID=2
a=fmtp:96 streamtype=5; profile-level-id=255; mode=AAC-hbr; config=1190; objectType=64; sizeLength=13; indexLength=3; indexDeltaLength=3

Thanks in advanced,
DBQ.