[mythtv-users] Equipment setup q's from a noob.

Robert Johnston anaerin at gmail.com
Tue Mar 28 20:10:56 UTC 2006


On 3/28/06, Jeff Simpson <llcooljeff at gmail.com> wrote:

<snip />

> 7 different security cameras all recording at once, plus one live TV and one
> recording for 3 locations means a total of 13 tuner inputs. To do this, you
> will need 7 PVR-500 cards, and to be honest, I'm not sure that they will
> physically fit in one box, let alone have the bandwidth to be recording from
> all of them simultaneously.
>
> You will more likely need more than one backend server, just to hold the
> number of drives and cards you will need to support your needs. 1 hour of
> recording is ~2.2 gigs, so multiply that by the 24 hours you want buffered
> and the 7 cameras you want monitored and you'll get nearly 400 gigs just for
> the security camera loops. Doable, but figure you'll want a lot more space
> if you intend on watching TV.

Bear in mind that (For the "Security Camera" feeds) you don't need to
use near so much resolution. So you could record those at half-res
(360x240, say), and lower FPS (If you can tell the encoder cards to do
that), which will significantly reduce the bandwidth used. Also, I'm
presuming these security cameras have no audio feed, which will also
drop the bandwidth requirement.

However, you could also try something like "Motion", which watches the
cameras and enploys motion-sensitivity, so they only trigger and
record when something moves. This would also drastically cut your
bandwidth needs.

> >   I have sensors installed on the side of my house where there is a
> > camera on each side.  If someone is watching TV with a smart card that
> > is set to, I want a PIP to show up on their screen if someone walks on
> > the side of my house.  I want to be able to PIP any security camera at
> > any time. 1 or all of them, or just bring one to full screen at any
> > time.
>
> Picture-in-Picture should work for the security cameras the same as TV
> inputs. Not sure if there is any support for an all-at-once mode.

Nope. Only one PiP is supported.

> > I would also like to be
> > able to log in VIA the web and view any of my feeds.
>
>
> This one will be tough - I don't know about your internet connection, but
> mine can't handle a 2.2Gig/hour stream. You need at least 54mbps wireless or
> 100mb wired ethernet to view live. Transcoded you might be able to stream
> over a lower connection, but it wouldn't be a live feed.

See also the bandwidth suggestions above. And look into using VLC to
stream video, as that would do the work a lot better than Myth can (At
the moment)

> >   The real kicker, I want to be able to do all of this from ONE that's
> > right ONE dual or quad CPU box.
>
> It's not a CPU limit, it's a physical space and PCI slot limit (for the
> backend). For frontends, you will want to have a separate PC for each. It is
> POSSIBLE to combine frontends into the same box, but it gets complicated
> when you want to have any kind of interface (IR Remote, keyboard, etc). You
> can maybe put 2 or 3 frontends into the same box, but it's difficult.

It's also possible to (try and) use external encoder boxes (Like the
Plextor ones), which would free PCI slots, but would bog down the USB
bus. It's really a matter of "You pays your money, you takes your
choice" on that one.

> >   Is this possible?  Any help / equipment list would be very helpful,
> > and if 2 boxes are needed that is ok too as long as they can all
> > interact the way I want them to and they can reside in the basement in
> > a "secured" room.
>
> Master/Slave backends work together nicely, and you should have no problem
> having multiple backends. The Frontends however, you will want to have close
> to the viewing TVs. Video signal degrades quite a bit over long runs, so
> it's best to have the frontend right next to the TV it is connected to, and
> only have ethernet run back to the backend.
>
> As far as required equipment, you are looking at a LOT of equipment. At
> least two backend servers, a total of 7 dual-tuner cards (PVR-500), at least
> a terabyte of disc space. You wanted to record/watch from 3 and watch from 3
> more, so you need a total of 6 frontend systems. This means you'll want 6
> PCs with TV-Out, 6 TVs, and 6 IR Remote setups (or wireless keyboard). You
> can possibly combine them to 3 PCs, each with 2 video cards or even 2 PCs
> each with 3 video cards, but the setup gets a lot more complicated.

...Or alternatively, grab 6 second-hand XBoxen and use those as Myth
frontends. If you don't want them able to play games on the XBoxes,
simply do a total conversion of them, including wiping the HDD, and
set the dashboard to start from the HDD (Into Linux and therefore
Myth).

> As far as total cost goes, estimating about $150 each for the PVR-500, $1500
> or so for the two backend servers, and $600 each for the frontends, you are
> looking at a SERIOUS investment here. (Around $6k)

See my Xbox comment above.

> As far as the purpose goes, is this entire system just to prevent your kids
> from watching TV? It seems that it would be much better to just tell them
> not to watch TV and have some kind of punishment if they do. I think I would
> sooner physically lock the coaxial cable input than work up a complicated
> computerized television system.

Or a "Parental Control" PIN set on the Cable TV box, or something like that...

Alternatively, you could set the boxes so they can only play back, and
you control what gets recorded (Using something like XBMC, say).
--
Robert "Anaerin" Johnston


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