tcpslice is a tool for extracting portions of packet trace files generated using tcpdump’s -w flag. 94k.
You can download it from the following link: https://packetstormsecurity.com/files/download/14489/tcpslice-1.1a3.tar.Z
Source: https://packetstormsecurity.com/files/14489/tcpslice-1.1a3.tar.Z.html