With rtpbreak you can detect, reconstruct and analyze any RTP session. It doesn’t require the presence of RTCP packets and works independently form the used signaling protocol (SIP, H.323, SCCP, …). The input is a sequence of packets, the output is a set of files you can use as input for other tools (wireshark/tshark, sox, grep/awk/cut/ cat/sed, …). It supports also wireless (AP_DLT_IEEE802_11) networks.
Analyze RTP traffic using interface eth0 (-i eth0), fill in gaps (-g), sniff in promiscuous mode (-m), and save to the given directory (-d rtplog):