RTP packet measurement module enabled VLC
I've modified some codes of VLC to implement
RTP packet measurement module.
The modified version make a log of RTP
packet header into "rtp_packet_measurement_data" file,
which
is created at the pwd directory when you starts VLC.
Then a simple parsing
program which is in "vlc_source_root/modules/measurement/statistic.c"
will
parse and analyse the log and print out those informations to console.
total_number_of_packets =
largest sequence number - smallest sequence number
packet_loss
= recieved_packet_count / total_number_of_packets * 100
recieved_time = current_time.tv_sec * 1000000 + current_time.tv_usec
recieved_time
= recieved_time * 9 / 100
When we compare the received order with the sorted RTP packet log by sequence number, the position difference is the degree of dis-order. I've sum up all the degree of dis-order, then average it. For example, if the recived RTP packet order is "5,2,3,4,1" and the sorted one is "1,2,3,4,5", then the degree of dis-order is "8", because "5" is apart from its expected posiont by "4" and "1" is also apart from its expected position by "4", so "8" in total. the average is "8/5" which is "1.6". So the variance of packet dis-order is "1.6" in this example.
Division of Computer Science,
Department of Electrical
Engineering and Computer Science,
Korea Advanced Institute of Science and
Technology (KAIST),
373-1 Guseong-dong, Yuseong-gu,
Daejeon,305-701
Republic of Korea
Email: dhhan@cosmos.kaist.ac.kr
Phone:
+42-869-3554, Fax: +42-869-5554