tool to convert packet level pcap files to flow level data?

Hey guys,

I am looking for a tool that can read through pcap format packet level
data, and convert it to flow level data.

I'd give it pcap files, it would generate something like:

StartTime(seconds), EndTime(seconds), IP Protocol, Source IP, Source
Port, Dst IP, Dst Port, Source Packets, Dst Packets, Source Bytes, Dst Bytes

Anyone know of any tools that can do this before I go and attempt
writing something to do it?

Thanks!
George