Wednesday, March 07 2007 @ 02:17 AM EST
Contributed by: richardpitt
Now that we have our own Windows Streaming Media server, we've implemented a number of features and likely will implement more.
The one that most people will appreciate is the replay each night (camera time) of the day's video. This article is to let you know how this works and why it can be a bit fragmented at times.
We're using a fairly plain version of Windows Media Server, with archiving turned on. This means that while the server is serving up video on each of its channels, that channel's video is archived into a file.
The complication comes from the fact that we're also using the option that when nobody is trying to view the channel, it is not running. This means that when the last viewer stops looking, the archive also stops recording.
In general this would not be a problem - we actually are "our own customer" for each of the main 3 streams - herons and the two Sidney cameras (and soon will be for all of them) in that we have a process on our main web server that takes a stream to convert it into the flash video shown on each of the sites' main pages at 2 frames/second. This starts about 6AM and finishes about 6:30PM each day (early March - times will change as the daylight lengthens) so there is typically a single archive file for this period unless there are network problems with the original feed from the actual camera sites.
The complication comes when people use an old or cached version of the web page that accesses the cameras, or go directly to the camera feed itself if they figure out what that is. This (re)starts the server and adds to the archive - even if it is dark and there is nothing to watch!
The script that builds the playlist for the evening viewing can't know anything about whether a particular file only has darkness, so it may be that the first file (or several) will be of darkness. You'll have to skip these using the buttons on the button bar below the video window. Note that if you don't have Java installed, the buttons may not be there in which case you may have to sit through what may be hours of darkness. If you install Java, you should see the controls show up next time you load the page. Note that the free feed only allows the previous day's archive to be seen. The pay-for-view version will allow all archives to be seen at any time - watch for this option.