[mythtv-users] mythtv-users Digest, Vol 36, Issue 176

j.mcdowell at mcdowelltribe.com j.mcdowell at mcdowelltribe.com
Tue Mar 28 21:32:42 UTC 2006


  19. Equipment setup q's from a noob. (j.mcdowell at mcdowelltribe.com)
  22. Re: Equipment setup q's from a noob. (Jeff Simpson)
  26. Re: Equipment setup q's from a noob. (Robert Johnston)

> At the moment, there is no smart card access setup for myth, so you might
> need to go another route, perhaps a password or user-account-based system.
  One could use bio metrics, I know that is well supported under linux 
as a whole, however I am not familiar w/ MythTV yet and therefore it 
may not work.  It is however the very last of my concerns and something 
I would be willing to help to develop if it doesn't exsist.  Again this 
is the last thing I am worried about as punishment is always an option.


> 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.

  I can always break them apart, however it is important to me to have 
FULL feeds and not "Digital Zooms".  I.E. Some security system cards 
will support 5 pics on one screen while they record.  However, if one 
wants to play them back for any reason they are of very poor quaility.  
So as long as MythTV has good support for separate systems streaming 
back and forth w/ good quality I am ok w/ that.


> 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.

  I currently have 500 GB in my PC and 2 Gb ram, so space is not an 
issue w/ the cost of drives falling the way they have.  With the right 
rebate special I can get a TB for $220.00.  Those are SATA drives btw.  
Ram, same thing, so cheap w/ the right rebate it's sick.
  So a 2 TB SATA Raid would cost me 440.00, and again I am ok with 
that.  However, if I separate the boxes I should need 1.5 TB in the 
security streamer.

> 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.
   I am willing to allow certain developer access to my system if I 
build it, to develop features on worthy hardware.

> That's a working feature. It's not as simple as just putting the blank dvd
> in and hitting record, but it's not a very involved process. It's fairly
> easy to make up a DVD and even easier if you just want to copy the MPEG2
> recordings to the disc as data, since most DVD players can play raw MPEG2.

  I should be able to mod this to work just the way I want.

> 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.

  Again, I SHOULD be able to mod tihs to get a semi live feed, a few 
mins delayed.  And if I want to review video over the web, well that's 
a little ambitious.  If the problem is that bad, I can come home.


> 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.

  Again I have no issue w/ making a box for each TV, I guess the 
question remains will a celeron 1.2 GHZ work w/ 256 MB memory and if I 
am lucky I may have a pci slot in these things.  If not I can build 
what ever I need.


> 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.

  I have no idea just yet how mythTV works, I am just starting to read 
about it.

>
> 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.
>
> 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)
   Cost is an issue if it gets crazy, however, has anyone priced the 
cost of a security PVR latley ?  I couldn't get one for 6k that would 
handle all the feeds I want.  I have also seen cards that will handle 
up to 8 CCTV connections @ once.  I am still inquiring as to their 
usefullness.



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.

  Again this is the least of my worries, and as I get deeper and deeper 
into this.  It is possible that I will start developing like crazy and 
contribue quite a bit of useful code.


> Message: 26
> Date: Tue, 28 Mar 2006 14:10:56 -0600
> From: "Robert Johnston" <anaerin at gmail.com>
> Subject: Re: [mythtv-users] Equipment setup q's from a noob.
> To: "Discussion about mythtv" <mythtv-users at mythtv.org>
> Message-ID:
> 	<b75f78d70603281210r402b0f5fxea70d6c0f1f1dfa0 at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> On 3/28/06, Jeff Simpson <llcooljeff at gmail.com> wrote:
>
<snip />
> 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 don't care about the quality on MOST of my cameras, however, the 
front of the house and the sides I want all but HI-DEF. :D


> Nope. Only one PiP is supported.
>
  That is something that I would be willing to "Re-code" once I get 
into it and have a good understanding of how and why everything works.  
At the moment I understand how a watermelon comes to be better than 
mythTV.


> 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)
  This is something I SHOULD be able to do w/ exsisting utils and a 
little scripting.

> 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.
   I will want to go with the options that work best, USB has been 
discussed and dropped due to it's limitations.

...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).
>
  I have thought about this, and they aren't flexable enough for me. So 
I have been thinking that a BASE Athlon 64 w/ 1 gig ram would be more 
than enough.  I can make this small enough to hide inside my 
entertainment center.  It's the BIG BOY w/ all the discs that HAS to 
remain in the basement.  So hopefully MythTV will use the master / 
slave thing VIA TCP/IP so there isn't any let down in signal quality.

> 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).

  Again this is something I would be willing to "Develop" once I have 
an understanding that is better than what I have now.  I think I relly 
should have just built one before posting here.  So I beleive that will 
be my next step.

> --
> Robert "Anaerin" Johnston
>
>


  Joshua McDowell





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