Resolving protocol names in custom tshark display filter

I want to parse the standard header outputs of tshark. Since the default doesn't work, I am using a custom field parser that does almost the same thing. What I am missing is the resolution of the name of the protocol. My command is:

sudo tshark -b 256 -P -T fields -e frame.time_epoch -e ip.src -e ip.dst -e ip.proto -e ip.len -e col.Info -E separator=';' -b filesize:65535 -b files:10 -w tshark_tmp

This almost works, what I get is (this example is capturing two pings):

1378869929.862628000;192.168.78.252;192.168.78.53;1;84;Echo (ping) request  id=0x0abe, seq=65/16640, ttl=64
1378869929.863188000;192.168.78.53;192.168.78.252;1;84;Echo (ping) reply    id=0x0abe, seq=65/16640, ttl=64 (request in 1)

The same two pings look like this in the normal, no custom field tshark:

0.000000 192.168.78.252 -> 192.168.78.53 ICMP 98 Echo (ping) request  id=0x0abe, seq=13/3328, ttl=64
0.000707 192.168.78.53 -> 192.168.78.252 ICMP 98 Echo (ping) reply    id=0x0abe, seq=13/3328, ttl=64 (request in 1)

The main difference that I need to solve is in mine I get 84 for the protocol, whereas tshark prints ICMP 98. I could implement my own lookup table, but there is a large number of protocols and tshark already knows how to decode them, I just need to figure out how to get that in my parsing.