Fabiana moreno wrote:
I'm streaming a video and i want to know how many frames i have lost
when streaming.
How can i find out how many frames i have lost when doing a capture?
I know the same timestamp means same frame..
So when i have incorrect timestamp or wrong sequence in rtp analysis
this mean that the frames are lost?
streaming video usually denotes UDP, so you can't do sequence number
analysis. However, there are clues that you can use to find missing
packets.
1) Look at the IP ID field. Do they increment uniformly? They may not
if the publisher of the stream is servicing more than this one stream.
But if you're lucky, it may increment by one, or by two. If all of
sudden they increment by two or four (respectively), then you may have
lost a packet.
2) See if the streaming server puts any identification within the
packet itself. You may be able to find a few fields that are
incrementing uniformly. Again, it may be a clue as to how the packets
are "timestamped" for application tracking. By timestamp, I mean a
counter and not the packet's absolute capture time.
3) This may be the most reliable (but not scalable) way. Capture at
the publisher and some consumer. See if the same number of packets are
captured on both sides.
Unfortunately, for case #3, the old rule of engineering kicks in: you
can have it fast, cheap, or reliable. You can have any two, but not all
three.
--
Thanks,
Hansang
