problem with rtmp url

have anyone tried to manipulate the rtmp url?

we have irule as below

when CLIENT_ACCEPTED {

TCP::collect

}

when CLIENT_DATA {

log "A --- Here is the length of the payload: [TCP::payload length] B --- Here is the payload content: [TCP::payload]"

}

the goal is to parse the rtmp url as we can find out with tcpdump or in wireshark

rtmp://x.x.x.x/aaa/bbb

but the result of the irule is like

A--- Here is the length of the payload: 1452  B --- Here is the payload content:  |÷xUΫ6/Åp²fÔ a¢.6Õü+c)Â.çÇÉ°µ³Eߨ9ê;Èy hü+c)Â.çÇÉ°µ³EßrXÏëâM¤.Äÿ¡{@oÉuwMùÊ÷H5!RTâZ驨´ÅIon×ƶ¼ÈAWRåýäò Mí^ô¯Þµ¡!
                                                                                                                    ¬ÍØi²SÔioPþüz¯0>  sËwãEieÐ×kb²*ùPQÈ£ OL6 ©Àñ_K|÷¶Ã}¦       a;ÿ|É@8u7Ó8.AkÕuwMùÊ÷H5!PÎÐÛ´Ãdá~5iãvÁ®
                                                                                                     ·ö׫2ùð¤ôm

any advice will be very appreciate!!