[mythtv] Hosting questions...

Robert Johnston anaerin at gmail.com
Mon Mar 20 03:10:25 UTC 2006


On 3/19/06, ralf <puzzler at arcor.de> wrote:
> Folks,
>
> i am new to this list, but not new to open source itself: great
> work with the MythTV, just amazing, how much work you have pulled
> together!
>
> now my question, please bump me to the right list, if I am wrong here.
>
> i showed my uncle my brand new mythTV recording station in the
> living room and he turned around and gave me work :-)
>
> he owns an apparmenent complex in Frankfurt, Germany where 12 different
> people rented an (quite expensive) appartment. He supplies the whole
> complex with a 2 MBit leased line, which is part of the rent.
>
> Now he wants to offer his renters a digital video recorder and I was
> keen enough to tell him: I can code it!
>
> Well :-) big mouth, big mail....
>
> Is it basically possible to have 12 DVB cards controlled from one source?
> I am quite good with PHP and Linux and as far I can see from the docs,
> it should be possible to setup 4 boxes with 3 DVB cards each, connected to
> a NFS storage and let the people login and record their stuff.
>
> Before I start to dig further, I just wanted to have assurance from this
> list:
>
> Is it possible to offer 12 different users simultanous recordings on 12
> different channels? (I will be smart enough to recognize duplicate
> schedules)
>
> And secondly: 2 MBit is not a very thick line, if you talk GIGABYTES...
>
> I saw during config the input values for a Win32 encoding lib. Would it be
> possible to encode the stuff on-the-fly (realtime) into a higher compression
> like MPEG4 or wmv to save 50-60% of space?
>
> Any hints before I stumble into the unknown are welcome!

First of all, this does sound feasable, but there are a few caveats
that I would point you to first.

In thoery, you could lock each person's frontend box to a "Recording
Group" to keep their recordings for their eyes only. However, there
would be nothing in the code to stop them erasing another person's
scheduled recording, and they would see the recordings of other people
on their program guide (And might not be able to claim the recording
for themselves - So if person A wants to record "Lost", person B can't
then record it, as it's in person A's recording group. Or, if myth
will allow a recording to be in two groups at once, it'll be deleted
by the first person that hits delete, no matter what the other one
wants (I'm not sure on the "multiple-recording-groups" issue here.

One way you could try this is to have 12 single-card backends linked
seperately to 12 frontends (So all the backends are seperate). This
will work out a lot more expensive, however, but it would secure one
person's recordings from another's.

Also, even if the Internet link is 2Mbit, you could place the Myth
Boxen inside the network there, giving a full 10 (or 100)Mbit
connection while not taking any of the 2Mbit internet "space".

You will also need to ensure there is a LOT of storage available.
Taking worst-case scenario into account you'll be looking at 4GiB/hour
* 24 hours * 7 days * 12 users = 8TiB storage. Possibly more for
top-quality and top-resolution HD.

Let us know how it goes. :)
--
Robert "Anaerin" Johnston


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