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?

Most of the system in testing prior to use

On Tuesday night, Insanity Radio did a hugely successful outside broadcast from our student’s union event night. What we did was actually revolutionary in terms of the SU’s radio, and certainly isn’t something I’ve heard of another student station doing. The result was fantastic audio, a great sound overall, and a fun night. And near-zero latency. Here’s how it worked.

We used a fairly simple setup in principle – we planned on having a wireless link to get our OB computer onto the campus-wide wireless network, then using NetJACK to send audio from the JACK server on our OB computer across the network to another JACK server located in the studio. From there, we used alsa_out to get audio out to the sound card, and from there went into the studio desk.

However, the clever bit is this- we also had JACK managing the audio for the venue as a whole. We had audio going straight out of the OB computer into a balancing line-isolator (a Sonifex RB-BL2) and from there into the venue’s PA system. JACK is so low-latency that doing this is actually fairly simple, and while the DJs noticed the latency with their monitors a bit, they were fine with headphones and didn’t complain about it at all. For comparison, we had people using microphones to address the crowd and they didn’t notice a thing. NetJACK using CELT over wifi works fine – we used a 32kbps bitrate and used 3-packet redundancy, with a mono feed. We actually ended up managing to use a wired link and thus could probably have gone further but we didn’t test wired so didn’t want to risk an unreliable link given that the low-bitrate feed was actually very listenable. We ended the 6 hour long outside broadcast with a mere 20 netxruns, none audible.

This is all well and good but you might wonder why. Well, here’s the why of it- we essentially at this point have a JACK server with the physical and network outputs on the output side, and the inputs (actually the sum of a Behringer Xenyx desk put through a line-isolator and taken in on line in) from the DJs and microphones. But we’re a radio station! We want jingles, and occasionally we want to run our own music. So let’s do that!

Set up in all it's slightly-messy glory

We sadly don’t use Rivendell as our main playout system yet, but that didn’t stop me from pushing it into service here. We used Rivendell for jingles and music, with a master log set up with enough music to do the show if a DJ didn’t turn up, plus a sound panel loaded with jingles we’d had made for the event. Rivendell can be set up to use JACK so we could handle this easily. We then had a software mixer – jack-mixer – with the desk and rivendell as two inputs. The output of this went into jack-rack with a fast lookahead limiter to stop nasty transients going out. And to make this easy to monitor we had 6 instances of JKMeter running – one for prefade and one for postfade of both rivendell and the desk, and another pair before and after the limiter. This makes for an excellent view alongside RDAirPlay, and allows rapid debugging of any problems as well as good level monitoring.

Of course, being able to see what’s going on is nice, but nothing’s as good as having a proper hardware interface for mixing. So we threw a £30 Behringer BCF2000 into the mix, plus a2jmidid to bridge the ALSA and JACK midi ports. This let us put hardware faders on software controls, for both jack-mixer and jack-rack. When doing fast, smooth transitions this is what really helps to make the system usable.

But to what end, you might wonder? So did most people, till the DJ finished a song, only to have it smoothly picked up with a “You’re listening to Insanity Radio” jingle, swiftly followed by “Coming up next: Your 2011-2012 President of the Student’s Union” to be met with massive cheers from the crowd… and suddenly in comes the announcer, loud and clear on the mic.

Ideally we’d have run this with a good external soundcard with plenty of solid I/O on balanced connectors instead of using a desk to submix to a stereo feed then putting that into a balancer; that would have let us put every single channel on it’s own jack-mixer input and apply compressors to the microphones, for example. Still, nice to know there’s room for improvement! The event was a success, overall, though we had a few interruptions from our silence detector that marred it somewhat. And we managed it all on a budget of £0, using only what we had lying around- so that’s a win!

NetJACK is very promising and as I mentioned in #rivendell and #london-hack-space on freenode, there’s a lot of potential here – particularly using the bidirectional and low-latency nature of NetJACK you could do talkback between OB and the studio, you could fairly simply set up remote monitoring of feeds at the studio, and so on.

If you want to listen to some of what we did, have a listen – the audio on that page is largely unmodified, aside from the inclusion of the first jingle and removal of all the DJ music (for licensing reasons). All the overlaid jingles and transitions are as they went to air – which is why we messed up the recording a bit, as we’d failed to disable the silence detector in the chaos after the people with the results didn’t turn up till an hour after schedule! Next time, record locally…

For the real geeks who want to do this themselves: We were using Ubuntu 11.04 Alpha (thoroughly tested beforehand) with the kxstudio PPA packages for jack, libcelt and friends. SSH was used to control the endpoint machine from the OB, and our wifi module of choice was the Ubiquiti Bullet M2HP with an 8dBi omni antenna.

A couple of months back we worked with E-ON to put an advert in the magazine as well as running a login screen advert, and this has now run. So for a few days anyone logging into EVE will have been greeted with this fine advert created by Zapatero at MMM Publishing.

Of course, this suddenly meant more people going to and using the site. Fortunately one of the primary concerns when myself and Makurid put EM2 and later EM3 together was scalability. Whereas EM1 would’ve fallen over and died, EM3 has soldiered on like a champ. The only intervention we’ve had to perform was to fix the API processor, which was hanging regularly and causing problems as a result. That’s fixed, and we’re now stable and responsive. So, of course, we now have some numbers! These are the statistics for the most recent 30 days as of this post.

• ~85,000 visits
• ~500,000 page views
• ~5 pages per visit
• ~29,000 unique visitors
• ~1,500 additional account registrations as a result of login screen advert (Above ~20 account registrations per day baseline)

In terms of the site’s dataset, we’re getting fairly huge.

• 6,000 EVE API keys, of which 4,000 are full keys
• 75,000 EVE API methods enabled
• 32,000 EVE API calls per hour (about 10 every second)
• 75,000 characters (includes characters noted in market and other data)
• 15,000,000 wallet journal entries
• 6,300,000 wallet transactions
• 200,000 EVE Mails
• 1,600,000 active market orders
• 6,400,000 EVE API loaded trades
• 52,000,000 Inferred trades
• 11,000,000 processed uploads
• 146,000,000,000 total skillpoints of loaded characters
• 4,100,000,000,000 total ISK of loaded characters

Which is… scary. But! We’ve grown hugely (a threefold increase in requests per second) and we’re still performing well. The site is not throwing errors, users are generally happy with their experience with the site, and we’re stable – no crashes, no fires breaking out, no climbing resource usage. Our caching and design philosophies have worked well and the extra effort invested earlier in development has really paid off. We’ve just handled a huge amount of growth with no effort at all. I’d estimate we’re good to around 12,000-15,000 users on our current hardware.

Of course, we’re now wondering what to do. I stopped playing EVE long ago aside from the odd spot of tinkering, but I’ve even let accounts lapse and stopped updating my skill queue as of a month or two ago. Makurid’s just started playing again recently. We’re not really heavily invested in EM in terms of motivation, other than making a cool webapp.

Capsuleer, as I’m sure many of you know, is an EVE iPhone app that recently shut down because it couldn’t be monetized and the time and money invested in it by the developers was simply unreasonable. A couple of weeks back I was looking at the realities of what EM costs to run, and what it costs in terms of time to maintain. And the logistics of, if needed, shutting the site down. This is still somewhat in my mind but the site will be sticking around for a little while yet. I’m very much hoping CCP will come to their senses in terms of how they choose to support third party developers (a free account subscription appears to be the greatest gift given by CCP, but that’s a far cry from the ~£130 per month it costs to run EVE Metrics – and that’s just our costs _now_, not including new hardware costs or upgrade costs. If we grow much more we’re going to be looking at ~£200/mo to run EM, possibly more). Advertising isn’t an option, and donations have failed every time we’ve tried to support ourselves with them. Timecode sale affiliations barely made a mark on my accounting sheets. We do enjoy writing sites and producing something big that people find useful, but there are certain realities to be faced – both myself and Makurid are students, with no full-time jobs. I’ve recently picked up some part time work which means I can now afford to buy bacon on a weekly basis again.

In the meantime we will continue to support the EVE community by maintaining EVE Metrics. We’re working on the codebase right now to upgrade it to the latest and greatest Rails release and Makurid’s beavering away at the API processor to split it up into a puller and a processor, enabling us to achieve much higher throughput on API calls to CCP’s (slow) servers. Now that we’ve breached 30,000 requests per hour, that 10 request per second figure is actually beyond our capacity right now because of our single-threaded processor/puller mechanism. This is actually a CCP limit- we just need to work around it by hitting them with more requests simultaneously, thus spreading our load over multiple servers on their end. I’ll also be making performance and usability improvements wherever I can and incorporating as many bug reports as possible into what we release. This will likely be a slowish process, but in the long run, it should be worth it. The question really is, will CCP make it worthwhile for us to be investing our time and energy into longer term planning?