How I can make scapy read MGCP packets from a .pcap file?

Question

I use scapy for MGCP. I started off with reading a .pcap file with MGCP packets.

For example:

from scapy.all import *
from scapy.utils import *
from scapy.layers.mgcp import *

mgcp_pkts = rdpcap("my-mgcp-capture.pcap")

However, rdpcap() is returning all MGCP packets as UDP packets. The output is something like:

All 262 UDP packets are actually MGCP packets. 

I would have thought rdpcap() will understand MGCP packet format.

Would appreciate help on how I can make scapy read MGCP packets from a .pcap file.