The SWF player code can be found on several sites, such as LongTailVideo, FlowPlayer or several others. The 'flashvars' section points to the Wowza server IP and application name, in the example above 'live' and then the content you wish to play, so Extremists.flv (found as the default content upon install). So the above would be hosted as a file on your webserver, or generated by some of your own PHP code, making sure you have the swf in the correct location as well.
Wowza is not a webserver, although does have a web service to allow certain types of integration.
So if I've get it, there is no swf player provided with WowzaMediaServer.
In the case of vod, wms is "just" a streaming provider, right?
you are correct, the SWF is the client code required to connect and play a stream. There are many free for personal use and then chargeable. Some examples do come with the Wowza server and could be modified for your use if needed.
It's not clear to me the flashvars specification:
file, type, height, width
where are defined these parameters? I suppose they are different for each players
That is correct and I just provided an example what you might expect to see for one of the player , LongTailVideo player. Each player would need to be researched a little.
Now, my final purpose, is to create a videochat inside my website.
I've followed the videochat tutorial:
Here the things are a bit more complicated, because there is no .flv file to specify.
In the tutorial we specify publish,play, and server variables. I suppose that these are variables processed by the videochat.swf file provided with the tutorial.
That is correct, the SWF Processes these so connecting to the correct server.
Is there a player, like LongTailVideo or others that allow me to create a videochat application? What is the role of WMS in this case?
If I would like to track the duration of a videochat? Should I code that on the server (maybe with Java wms extension?) or within the swf client itself?
The player ,SWF, usually needs a server to connect to as the server will process the chat messages and video for each end, and possibly allowing more than one connection at a time.
To track duration and other elements you can use the log files produced by Wowza, but if you wanted something different you would need to code it yourself.