Perl script to export Sequence numbers & data rates of QoS Data frames from pcap file to excel sheet?

Please try this:

tshark -nr input.pcap -T fields -e frame.number -e ip.src -e ip.dst -e tcp.seq -E header=yes -E separator=; > output.csv

Furthermore, you need a display filter for 'QoS' frames. As you did not specify what kind of QoS frames you are talking, I can only tell you how it works in general.

tshark -nr input.pcap -Y 'tcp.port eq 80' -T fields -e frame.number -e ip.src -e ip.dst -e tcp.seq -E header=yes -E separator=; > output.csv

Please replace tcp.port eq 80 with your filter for 'QoS' traffic.

BTW: Please also define what you mean by: 'data rates' of QoS data frames.

Regards
Kurt