So when I moved in to my current university digs, the previous tenants had left a few things behind. Notably, they’d had Sky. So we had a Sky box in the living room and a dish on the wall. In the UK, if you want fast internet these days, you need Virgin Media. VM gives you cable TV in the bundle, so I didn’t want to pay for Sky. But Freesat’s got some nice stuff on it, including BBC HD and that sort of thing. So how about we get ourselves some free TV?

Now, Sky uses the same satellite for the UK as a lot of Freesat stuff. So ignore the dish- all you need is to leave that bit alone, and make sure that you’ve got a cable from the dish LNB to somewhere you can put your PC. Where it’s pointed is probably 28.2 East, which has a bunch of appropriate satellites.

What you then need is a capture card. DVB-S is the standard for satellite, though DVB-S2 is used for some HD encoding (specifically, BBC HD is now on DVB-S2). DVB-T is for terrestrial stuff, and comes in on coax from a standard TV aerial – you can get combo cards, which will let you pull down extra stuff if you’ve got the coax feed. Stuff from your LNB typically comes on F-type cables/connectors, down 75 ohm cable. I have yet to find a decent UK supplier for patch or extension leads – if you know one, let me know.

The LinuxTV wiki maintains a huge list of hardware compatibility with Linux and capture cards, so check there before you go buy anything. I got a Compro S350 card, which works great for DVB-S – I’ve also ordered a Technisat S2 HD card, which should do DVB-S2, and I’m going to look out for a DVB-T card.

Now, we need to tie all this together next. So we need some software and a PC. The PC wants to be a decent spec – I’m using a Pentium 4 box with 768MB of RAM as my server, which is on the low end of things. A faster machine would be better, obviously, but it’s all I have to hand. I stuck a decent (GeForce 6600) graphics card in there, too. Fast CPU is the priority, really- we’re talking high definition decoding, encoding, transcoding and playback. If you’re on a budget, look into Intel quad-core chips (Q6600s, that sort of thing). Intel is the way to go wherever possible. If you’re doing this properly, high-end i7 would be my choice- that or a Xeon or similar. 6-12 core chips would be just the ticket. High-end (newer 8800 series and above) nVidia cards support VPDAU, which lets you offload video decoding and processing to the GPU.

The software to use is MythTV. I’m using a standard Ubuntu 10.04/11.04 (‘Classic’ mode on 11.04) install, and then installing MythTV atop that. On the server, just install the mythtv, mythtv-themes, xmltv and mythweb packages. On any other clients you can install the mythtv-frontend package, and optionally the mythtv-themes package. The client-server model of MythTV means you can combine backends and frontends to build your system. It’s crazy powerful in terms of flexibility. But the short story is, you can have a very nice TV system in very little configuration.

See this excellent guide for more information on how to set up MythTV with Freesat. Basically you just need to tune it in to the right satellite and set up the input properly so it’ll get the channel list. MythTV’s config options take some getting used to, but it’s eminently doable. And once you’ve gotten everything talking, you have a -very- capable system.

So, well done to the MythTV team. One hell of a package, that’s for sure. And Linux DVRs are now in my mind far, far more capable than any other potential choice for DVRs. With MythWeb, I essentially have my own private little iPlayer- but for every single bit of Freesat’s programming. What’s not to like?

Our electoral system is essentially a popularity contest. Manifestos, campaigning and student outreach have very little impact on the results. Many positions are uncontested and whoever runs wins by virtue of being the candidate who is running; people assume that this means that they care about the position enough to run, and that’s enough for them.

I don’t think this is a good way to run elections, and it’s not something that should be encouraged. But it’s something that can be very easily fixed, or at least I think so.

Essentially- why not make the candidates unlisted? Let’s say there’s a candidate running for a position- let’s call them John Smith. They’ve been out hard campaigning throughout the week, and you’ve just gotten canvassed by this candidate on your way to the library. You sit down and decide you should probably vote, so you grab your laptop or a public terminal and load the website up, log in… and vote.

But here’s the crucial bit. We use alternative transferable vote for most of our elections, which requires you to put a number by each candidate, ranking them in priority. There are also two meta-options: re-open nominations (RON), and no further preferences (NFP). The way this is presented to you is as a list of all candidates, followed by the NFP/RON options, and you just type in a number by each option in descending order of preference.

The lazy voter just sticks a 1 by the only candidate and hits vote. If we’re lucky (in terms of improving democracy) they vote for RON as their second preference, or maybe they even vote RON for first preference. In terms of improving democracy by encouraging people to go out and canvass for their position (which is more likely to discourage people running for the sake of running/sticking it on their CV and encourage people who care enough about the position that they’re willing to go out and get people voting for them), the ideal option is that people vote for people they’re aware of through canvassing (online or in person) and vote RON for any positions they’ve not had any contact from people over.

So how can we encourage this over the default impulse to vote for whoever’s running? Simple- we remove the candidate’s names from the ballot. “What on earth is he on?”, you may well be thinking. Well, here’s the thing- if we remove people’s names and require people to actually enter the name of a candidate they want to vote for, people cannot just vote for people because they’re running; they won’t know who is running, if anyone. Of course, they can go find out who is running by looking at the candidate and manifesto listings. But this encourages people to find out more about who they’re voting for, and discourages lazy voting- both good things for democracy. Canvassing gets your name into people’s heads (and, through flyers etc, into people’s hands, making the process of voting even easier).

And because our votes are 100% online, the process of typing in someone’s name can be made easier – if we want to vote for John Smith, we type J and are immediately autocompleted to John Smith. This entry is now an entry we can put a preference number by (or in perhaps a better UI, we could have draggable lists to make specifying preference easier). This stops people with complex names from being disadvantaged against other candidates in elections.

So with this system, the view that would greet you on any election position vote page would be “Hello, this is the election for the position of X. Type a candidate’s name in below, re-order the entries so the option you most want to win is at the top and no further preferences is above any entries you don’t want to cast a vote for, and press vote”. Voters would either just click vote to vote for re-open-nominations, or could go look at the manifestos etc and see who’s running and why, type in the people they want to vote for, drag the markers around, click vote, confirm their vote after seeing a screen detailing their vote, and then they’re done. Simple as that.

I figure I might do a quick proof of concept system that demonstrates what I’d imagine a voting UI to look like that used this system. I don’t see any major downsides to this system, but I’d love some feedback if I’m missing something obvious. And if people think it’s a good idea, who knows- maybe we’ll get this to a general meeting and see about making it the standard, or at least get it trialled.

Okay, so, Backchat was hugely interesting as a project. Eventually, I produced a set of graphs using the classifier that showed sentiment over time. These graphs aren’t too accurate but are fairly good at showing how things were going. However, after this I pretty much dropped the project. This was mainly due to exams cropping up and stealing my time away, but also because of how difficult it was to approach a sensible level of accuracy.

In my ‘final’ design I ended up using a bigram classifier. I added parsing of the tweets to pull out mentions of words, URLs and users, and then used this to generate my training sets, which improved things a lot. This gave me several thousand tweets for each training set, which worked okay. However, even with this classifier, which was doing a lot better than most others, my results weren’t very reliable on a tweet-by-tweet basis. Still, it wasn’t too shoddy, and the graphs on the right are fairly reliable I think in terms of general sentiment.

The AMQP-linked network of processors worked extremely well, and resulted in good throughput- I used two parsers, two classifiers and one classifier loader in the end; I was unable to achieve realtime performance due to network constraints. Sadly my ISP at home had decided that I’d used too much bandwidth and clamped me down to 128 kilobits a second. That said, thanks to the streaming API I did not (as far as I know, except for a few hundred to ratelimiting) lose any tweets, I just received them out of order and then reconstructed the correct order using the timestamps for each tweet. The machine I was using for this also pretty much went flat out on disk I/O and CPU usage, but was able to keep up- it’s a fairly old box, only a Pentium 4 with a couple of gigs of RAM.

In any case this was an interesting project and I’ll be open sourcing the data and source in the coming weeks if anyone wants to have a poke at it. While the debates are now gone and done, I’m sure people can come up with some great uses for sentiment analysis outside of UK politics.