Digital convergence

[fanf]

I had some interesting ideas on the journey home last night.

Tivos are really excellent things that make it simple to time-shift telly so you can watch what you want when you want, instead of either watching crap or not watching it at all. However in its usual incarnation it has the disadvantage of not being able to record more than one channel at a time because of limitations in its tuner.

However if it were integrated with a digital receiver it ought to be able to record all the MPEG streams symultaneously. This would rule. (Does the Sky Plus digital satellite receiver with digital video recorder do this?) Since radio channels are also broadcast over the same medium, the Tivo could do its thing for them too.

At this point what you want is to be able to hot-sync your iPod with your Tivo. Or alternatively, put the DAB receiver and Tivo functionality into the iPod itself. This would also rule.

Comments

[saraphale.livejournal.com]

I think the Sky+ box has two decoders, one can be used for watching TV while the other is used for recording. I think the patch to record two channels at the same time is still in the works, but I'm not sure.

You'd need a large amount of disk to record all the streams.

[fanf]

I was thinking of recording selectively but permitting overlaps -- there's no point in recording disk-wasting shit.

[http://users.livejournal.com/_nicolai_/]

Recording many MPEG streams would require a serious disc subsystem. It would be nice to do, say, "any three" or similar. "All of them" is going to require a serious piece of equipment probably manufactured by SGI, and I already have enough computational space heaters in my house.

Nicolai

[fanf]

Surely all it needs is a decent filesystem and/or write cache.

[saraphale.livejournal.com]

Most of it will compress nicely to a jpeg of the word 'CRAP' in 72pt Comic Sans MS.

[http://users.livejournal.com/_nicolai_/]

A TiVo at medium quality runs about 2GBytes/hour of disc space.
That's 582Kbytes/sec. I'm guessing a typical IDE disc used for this purpose will realistically sustain 4Mbytes/sec (TiVos use lower performance discs because they're quieter and cooler). So 7 such MPEG streams will pretty much saturate your disc, however good your filesystem is. I'm assuming your filesystem overhead is negligible here, since you can arrange for the storage methodology to be optimal for you.
So recording the 50-odd channels that I get even on my fairly basic cable service is going to need the thick end of 30Mbytes/sec continuous write performance. I get that from one of our large hot noisy power-hungry SCSI/FC-AL raid arrays at work, and I don't get it at home.
I think you will struggle to get more than half a dozen channels recorded continuously on consumer-grade hardware that you might want to share your lounge with.
However, being able to record at least 6 simultaneous programmes before I miss anything to due to scheduling conflicts would do me fine.
Nicolai