Hello, I'm looking for something strange here

I'm planning to make a website about local DVB-T channels that shows technical info about frequencies and channels, since I'm developing in PHP I would need a XML output to manage the data. Now I've seen that TSreader does that, the only problem with it is that I'd really like to capture a "snapshot" of X minutes of every frequency (with multiple channels of course) because of the variable bitrate to get min-medium-max values, since putting the information of an instant bitrate with the variable one is useless. The second problem but not so important is that I would like to do that every week for instance automatically.
There's plenty of websites (e.g. linowsat) who offer this information for SAT TV and they have all the data needed updated constantly so I was wondering how they do that in real time! what do they use? I found a UNIX script called dvbsnoop that I think it could be definitely be setup to run automatically but it won't output XML features (from the specs) so I really don't see how they (websites) manage to control the data.
I'm using Windows x64 but I could definitely use some Linux distro in a virtual machine (if I can use the TV card from there!!)

Any help?