Thousands and Thousands of Hours of PVR TV 264
Thomas Hawk writes "Cory Doctorow is posting over at Boing Boing about some technology that he apparently saw this weekend at London's Open Tech conference. According to Cory, this new technology from Promise TV takes the form of a home-built PVR with lots of high-capacity hard drives and claims to be able to record every show on every channel being recorded in the UK for an entire month. 'Why program a TiVo to get certain shows for you when you can record every single show on the air, all at once, and then use recommendations, search, a grid, or any other means you care to name to figure out which of those thousands and thousands and thousands of hours of programming you want to watch.' The company seems somewhat cryptic with a simple website that appears to be collecting your email addresses for an announcement in August. "
Re:5 channels (Score:5, Informative)
http://freeview.co.uk/whatson/index.html [freeview.co.uk]
I doubt you'd bother making something that recorded from an analogue source - too much CPU power.
Re:Timing (Score:5, Informative)
Seriously Doubt (Score:3, Informative)
I mean, just look at a standard Tivo box. 40G hard drive gives you about 35 hours of recording time. And that is just one or two shows at a time.
A month's programming on 200 channels simultaneously?
c'mon.
Re:Timing (Score:1, Informative)
The machine _was_ as simple as you think: a few grands worth of discs, one TV card per channel (with hardware encoding), and some reasonable hardware.
The control interface was custom.
(yes, I saw it on Sunday
Re:There are hundreds of UK TV channels (Score:4, Informative)
It would be relatively easy to record all the Freeview channels at once. You only need one receiver per multiplex, not per channel, then you just record the raw data stream which contains all the channels on that multiplex. IIRC there are only about half a dozen multiplexes. So 6 tuners would be enough to record everything on Freeview.
Simple Math (Score:5, Informative)
a) Number of channels included will be the minimum available to all.
b) It'll be "VHS quality" recording.
There are 5 terrestial TV channels in UK:
BBC1
BBC2
ITV (commercial)
Channel 4 (commercial)
Channel 5 (commercial)
We've about 50 via digital TV, and loads more via cable or satellite.
However there are only 5 available right now.
So, that's 5 channels * 24hrs * 28 days = 3360 hours of recording.
Lets assume a VCD bitrate of 1300kbit/s video 128kbit/s. Total 1428kbit/s.
Number of seconds in 3360 hours
= (3360*60)*60
= 12,096,000
So, for all that video we'll need
= 1428 * 12,096,000
= 17,273,088,000 kbit
= 17,687,642,112,000 bits
= 2,210,955,264,000 bytes
= 2,159,136,000 kilobyte
= 2,108,531 megabytes
= 2,059 gigabytes
So that's like 4 * 500gb drives plus 1 * 120gb drive to correct for the drive maker's marketing departments.
I'm using VCD/MPEG as a basis for this, they'll invariably be using a better codec, probably with far stronger compression.
One WEEK's worth, BBC Freeview only. (Score:2, Informative)
I was at the Open Tech conference and also saw this PVR box. Actually there wasn't much box to it. It consisted of several large capacity hard drives (maybe about five SATAs) and a few DVB PCI cards, connected to a motherboard on a wooden base, no case.
It recorded one WEEK's worth of video from, as far as I could tell, only the BBC's Freeview channels (BBC1, BBC2, BBC3, BBC4, News24, CBeebies, CBBC). The quality seemed fine judging from an episode of Doctor Who which went out on BBC3 the previous Thursday being projected behind the presenter.
Re:Seriously Doubt (Score:5, Informative)
That's only if you record at crappy quality. If you record at "good" (not "best"), you get around 15. Which goes real fast, let me tell you. What's worse is that there's no way to find out how much space you've used up or is available.
[/gripe]
Re:Is this really a feasible home appliance? (Score:3, Informative)
Re:Timing (Score:5, Informative)
Because the system was demoed at OpenTech 2005 on Saturday.
I was there and I saw it. So here's a bit more info on how it works. I records digital terrestrial televison, not analogue. I suppose it could be changed to use satelite DVB instead of terrestrial DVB - but you can't get a DVB-S card that decode Sky's encryption, so there's not much point. It records an entire mutiplex off the DVB-T card. They only appear to have one card, so they were only recording the BBC multiplex. There are 6 multiplexes in the UK, so I suppose to record "all" DVB-T transmissions, you'd need multiple cards.
As for costs, while the DVB card was quite cheap (they said around 50 quid) and the PC is faily inexpensive, the storage costs are about the same as a plasma tv - but falling all the time.
And where... (Score:3, Informative)
This experiment has been run before... (Score:3, Informative)
Then he spent 24 hours camping outside.
He wrote it up in 'The Age of Missing Information'. [amazon.com] (Amazon link provided for the reviews, no sales connection.)
Great book, I recommend it.
Now excuse me, I need to get back to /. before I miss something.
Re:Timing (Score:3, Informative)
Re:Seriously Doubt (Score:2, Informative)
Not optimal, but it IS a way.
Bemopolis
How it might work, and some calculations (Score:5, Informative)
According to http://erg.abdn.ac.uk/research/future-net/digital- video/dvb-trans.html [abdn.ac.uk] each DVB multiplex runs at 24Mb/s.
So, storing one multiplex for a month needs
(24/8)*60*60*24*31 Mbytes of storage = 8 Terra Bytes
So 8TB per multiplex per month just about doable at the state of the art, but not very likely.
I haven't checked how many muxes in use for different channels. I think it's about 3, so say 24TB all in. That's a lot of disks!
Re:Timing (Score:3, Informative)
You assume they're recording analog broadcasts, which they aren't. Recording UK terrestrial digital broadcasts requires no compression. It's already compressed. They're directly recording the Freeview [wikipedia.org] multiplexes.
Re:Timing (Score:3, Informative)
See http://www.flickr.com/photos/90983090@N00/2814720
Cheers,
dwm