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Inside Da Vinci

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Andrew Bowden Andrew Bowden | 14:05 UK time, Monday, 20 April 2009

This is Da Vinci.

Da Vinci - the test farm

No. You're right. This doesn't really look like a famous Italian polymath at all.

In fact this Da Vinci is a room in our office, commonly known internally by a slightly more down to earth name of "The Farm".

Da Vinci is our test farm, and contains about a hundred different set top boxes on which our services are tested - if you've ever built a website and felt the pain of having to test a website in Internet Explorer, Firefox, Chrome, Opera, Safari AND Konqueror (okay, that last one is probably just me!), then you might want to spare a thought for our test team who have to test on lots of different boxes - all with their own odd quirks and behaviours!

The room is mostly occupied by Sky and Freeview boxes with some Virgin Media and Freesat boxes and some integrated digital TV thrown in for good measure.

What's in the farm?

Set top boxes in the test farm

The majority of the boxes are split between two racks - one for Sky and one for Freeview. Each rack holds up to 48 set top boxes, and next to it is a bank of 12 monitors. These are configured to display four the output of four set top boxes at once.

Monitors in the test farm

As well as the set top boxes, the rack contains a plethora of equipment:

Multiplexers

These take the input of four set top boxes and combines it into one picture, for displaying on the monitor. There's also a button that allows a particular box to be displayed full screen.

One of the screens in the test farm

Audio Selector

The monitors in the farm have no speakers, and the sound of 48 set top boxes playing at once would probably drive our test team mad! So each rack has an audio switcher, which enables the tester to output the sound of a chosen box

Audio selector in test farm

Power setup for the set top boxes

This bank of big red switches enables individual boxes and multiplexers to be turned on and off, which is much easier than going round the back of the racking and pulling the power cords out! This might be done to reboot the boxes, to allow us to reconfigure them between our different playout environments, or just to save electricity overnight.

Power switches in the test farm

Telephone line selector

Sky boxes include a modem which enables the box to dial up and get information over the internet. At BBC Red Button, we use this functionality mainly to allow people to donate money to Children in Need, Comic Relief and Sport Relief.

Like the Audio Selector, we use the telephone line selector in order to save us having to install a telephone line for each box we have, or to have to plug and unplug each box when a telephone line is needed.

Hitting the right button

It's no good having a set top box if you've no way to control it. So naturally the farm also includes remote controls.

The Sky boxes all share standard remote controls - one for the standard set top boxes and one for the Sky+ boxes. This means you can perform the same test on a huge raft of boxes all at once.

Freeview is a different matter - every box has its own remote control and these are all slightly different. Sometimes one remote may work for several boxes made by the same manufacturer, however that's not always the case. This obviously makes testing on Freeview a slower process.

The box selection

One of our limiting factors in the farm is space. We have just enough room to contain the majority of Sky set top boxes on the market.

However Freeview also provides us with another problem due to the sheer range of set top boxes and integrated televisions available on the market, which number in the hundreds. There are far more out there than we have the space to fit in the farm, or time to test on. We try to have representative range of equipment.

Although there is a large amount of equipment, the majority use a small range of middleware providers which means that the boxes in the farm will show up the vast majority of problems.

Whilst the farm plays an important function, most of our product testing actually takes place at desks, using a smaller, representative range of set top boxes - although spot tests may be made throughout the build process, most of the testing in the farm tends to happen towards the end of a project as part of the preparation for launch.

Thanks to Niki Muttaluri from our test team for his help in writing this post

Comments

  • 1. At 6:42pm on 20 Apr 2009, liamgh wrote:

    Really interesting to see what is involved in testing set top box applications. Don't know if you know about this already but the LIRC project on Linux supports infra red transmitters: http://www.lirc.org/transmitters.html to simulate remote controls. Might be handy for testing lots of devices quickly!

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  • 2. At 10:07am on 21 Apr 2009, Andrew Bowden wrote:

    Hi liamgh.

    I remember we did try doing some stuff with infra red transmitters a few years ago, however they didn't always prove hugely reliable with all the boxes, or were too convalesced to set up. Maybe time to look again!

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  • 3. At 8:33pm on 21 Apr 2009, cabsandy wrote:

    Ack-we have loads more than that in our labs in VM ;-)Seriously, very impressive and I know how diffcult it is to test ALL types of boxes.Add in broadband and you get my drift!

    cheers

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  • 4. At 11:36am on 22 Apr 2009, Andrew Bowden wrote:

    Yeah, don't talk to me about the number of boxes we could have in there if we actually had the space!

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  • 5. At 1:58pm on 22 Apr 2009, PhilFluffy wrote:

    Andrew, there is a linux based hardware dongle available that controls sky set top boxes in a undocumented way through tones on the aerial port. Its a lot more reliable than LIRC and is available in usb multi device variants. I use one on my multi input mythtv system.
    Being usb, (they show up as usb serial) its probably possible to fit multiple dongles in at once. The actual command sender is a small shell script which plugs nicely into whatever takes your fancy. They list that they will custom roll a controller with more inputs if needed, so I imagine they are well up for building something that would be very useful indeed for your test rig.

    Dont know if I can post the url, but you can always mod it if not :D
    http://www.dusky-control.com/support.shtml

    Is your multiplexer under serial port control? I was working on some perl to do that about 8 years ago and we had pan and zoom and select going by web based java applet so we could expose it to the web and the manufacturer of the multiplexer was quite excited about the possibility but the client went with webcams on windows servers instead of commercial grade multiplexed cctv kit as it was recommended by a mcse qualified "outside consultant"!


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  • 6. At 6:26pm on 22 Apr 2009, kate_henderson wrote:

    Hi Andrew!

    It's amazing to see what goes on behind the scenes and how things are tested.

    Just to let you know - the link for Children in Need is http://www.bbc.co.uk/pudsey - Thanks for all the hard work you do for us on Appeal night! :)

    Kate

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  • 7. At 9:55pm on 22 Apr 2009, dwmalone wrote:

    Hi Andrew,

    Do you keep any PCs with DVB-S or DVB-T cards in your cluster? It might be interesting to include Linux+mplayer, Linux+Mythtv or Widows+MediaCentre (or some other combination) as test targets.
    David.

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  • 8. At 10:39am on 23 Apr 2009, Andrew Bowden wrote:

    PhilFluffy - can't say I'm an expert on multiplexer equipment, but I can tell you each one has two serial ports at the back of them - although they're currently unused.

    The Sky farm works quite well with our current system of pointing a single remote control at the boxes - using a Sky remote keyboard tends to work better as it has a better IR spread.

    Mind you, Sky remotes are right trouble makers. Because most of us have set top boxes on our desks, quite often channels get changed and boxes turned off because of someone two desks away is using their box. Some years ago someone (wish I could remember who) modded a Sky remote and put a piece of drinking straw around the IR transmitter, inside the remote control then re-assembled it. We should probably do that as standard!


    kate_hendeson - sorry about that! Not quite sure why the URLs got mixed up. I've corrected it now.


    dwmalone - we don't tend to keep DVB-S/T cards as a rule. Part of this is the fun of being in a corporate IT environment where PCs are quite locked down. The other reason is that for Freeview we also generally only support equipment that has the digital tick logo and as far as I'm aware there aren't any cards or USB devices that currently have them.

    One of the my colleagues did take quite an interest in the Myth TV MHEG rendering engine - I particularly like the way you can access the MHEG on recorded programmes.

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  • 9. At 1:14pm on 27 Apr 2009, richmansfield wrote:

    Hi Andrew,

    Most of the set top box farms I have worked with use something like a RedRat to control the IR (see http://www.redrat.co.uk/products/irnetbox.html)

    Cheers,
    Rich

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