I made the video demo that I promised last night. In this video demo I use ettercap and wireshark to show the difference in network traffic between a typical IMAP client and a Tinymail based one when we have an IMAP server that deals with QRESYNC, IDLE and CONDSTORE (like modern IMAP servers do).
Ettercap is a useful tool to follow the traffic while using the applications. Wireshark is interesting to see how frames are formed while the traffic is being transmitted. When working with GPRS, the latency can be very high. This means that with an interactive protocol like IMAP, the time to retrieve and send a frame (the roundtrip time) has a big influence on the network performance of the application.
In the video demo I explain the difference between the old way of working with an IMAP server, and the modern way with QRESYNC and CONDSTORE. My goal is to convince IMAP server developers to consider implementing both CONDSTORE and QRESYNC so that IMAP clients can make better use of the GPRS network, and of course to show that my precious little Tinymail is supporting this already, if available on the IMAP server.
You might want to give this really awesome screencasting program a try:
http://live.gnome.org/Istanbul
And yes, there’s a package in Ubuntu.
I tried both xvidcap and Istanbul. Istanbul simply just immediately crashed and xvidcap with XDamage gave me an mpeg with unupdated blocks. Especially when using a scrollbar. Without XDamage the speed of the movie was extremely fast (a website explained that this is because xvidcap drops frames because it’s too slow).
Last time Istanbul did not crash, the resulting video was also horrible. It had lost frames and the sound was simply terribly bad. Also the video quality was ten times worse than when using a camera.
But, yeah, a solution that “actually” and “seriously” just works .. would be a very good idea indeed.
My computer is a dual P4 with both its cpus clocking at 1.6 Gz with 2 Gig of RAM. Please don’t reply that it’s not fast enough. That’s simply not true (it can run five virtual machines that meanwhile record the video using VMWare’s codec).
Perhaps next time I’ll use VMWare to record a video. I didn’t have one set up for this. But indeed, that solution ‘just works’ indeed.