[mythtv-users] Tivo or build my own.. cost/time/capabilities help

Craig Huff huffcslists at gmail.com
Sun Nov 4 18:21:03 UTC 2007


We generally don't top post on this list, but I am interleaving my response
your questions and the responses that Dan already made.  You may already
have figured out the additional details I'm adding, but others scanning the
might not. ;-)

You either have to go to the list archive, which has some delay before
show up or join the list and either wait for the digest (up to a few hours
later) or
select to get all the e-mails separately.  Sounds like you didn't already
set up
to get the e-mails individually so you didn't see Dan's reply.  I am cc'ing
this in case that is correct.

On Nov 4, 2007 3:14 AM, Dan Ritter <dsr-myth at tao.merseine.nu> wrote:

> On Sat, Nov 03, 2007 at 06:17:51PM -0700, Kevin Duffey wrote:
> I reformatted your post into paragraphs. 72 columns: it's not
> just a good idea, it's... a very good idea.
> > What I want to know from you experts is, if I were to build my own
> > with an existing AMD XP1600+ box, 1GB ram, and about 160GB HD (willing
> > to buy larger if this is the path to go), will I get the same/similar
> > features that I can with Tivo.
> Mostly. Also, some features that TiVo doesn't have, or only
> makes available on certain models.
> > That is, without being able to run a
> > server, is there a way I can over the web, set up my home-built DVR to
> > record something while on vacation.
> No, running a web site requires running a web server. Apache is
> a good choice. If Comcast is blocking inbound port 80, you can
> set it on port 81 or 8080 or 16300...

There is more than one way to skin this cat, but you always have to have
a system running to "catch" the commands, whatever the means.  This
*could* include  making a system responsive to  wake-on-lan commands
sent over the internet.  Not sure I'd do that, though.  I'm not a big

> > Can I record two programs at once > while watching a 3rd recorded one.
> Yes; you'll need two tuners for that.

The number of programs that can be recorded simultaneously is the same as
the number of capture channels you have installed.  The Hauppauge -150 and
-250 cards are single channel analog (SD) capture cards that can directly
encode the stream to Mpeg-2.  The HD HomeRun is an ethernet attached
device which can capture two HD streams and feed them over the local LAN
to the MythTV backend for storage to the hard drive.

The number of shows that can be played concurrently is limited by the I/O
capacity of the MythTV system, which includes Disk I/O throughput, LAN
bandwidth, backend compute performance and more.  An XP 1600 may not
support much more than the load you asked about.  HD requires more
compute power because it takes more to translate the higher pixels per
second rate HD involves.

This is probable a good time to explain a little more about the MythTV
architecture.  The minimum configuration includes a database, a backend and
frontend on a single box, although they can easily be on separate systems.
Slave backends can also be configured to expand the recording capabilities.

Backends handle scheduling, recording, and managing the recordings storage.
The database keeps the data about upcoming shows, recording rules, and
options.  Frontends mainly are for converting the encoded file (in one of
formats including mpeg-2 and mpeg-4) into display data to present over the
standard video card installed or built-in to the frontend system.  This is
a specialized TV card.

Up to this point, Nvidia interfaces have been more successfully used, but
other vendors have promised to improve their Linux driver support recently.
The results have not yet been seen.

Both backend and frontend systems can be built with an ear towards silent
or at least quieter operation, but not with just any old retail store
parts.  You
may have to replace the power supply and cpu cooling fans and/or replace the
cpu with a newer, cooler running part to satisfy your ears, or live with
what you
have for the time being.  Even disk drives can be part of the

> > Can I share the video to more than
> > one TV in the house without requiring computers next to each... is
> > there some wi-fi (or networked) cheap audio/video converter that can
> > have a video streamed to it and just play to a tv.
> Yes, but it's a computer. I think the best supported of these is
> the MVPMC, but I don't use one.

The MVPMC is another Hauppauge product that is effectively a TV over
IP device.  It has an O/S image that enterprising souls in this community
have figured out how to replace with a Linux/MythTV image that serves as
a frontend.  IIRC, this has a reduced command set vs. a full-up frontend,
that can always change.

Almost anything is possible with a computer, but just as importantly, is the
result worth the effort.  Many video cards support multiple displays and you
could always install multiple video cards in a system, too.  Running A/V
cables to TVs in different rooms would be a challenge and getting different
shows displayed on them is another one that I have not seen addressed here.
You would also have the challenge of how to remotely control the display of
TVs not in the same room as the MythTV system.  It could be done with RF
remotes or additional IR receivers on long cables bundled with the A/V ones,
but I wouldn't do it, personally.

> > I see that the cost is basically that of the tuner cards (about $150
> > each for the PVR-250 I think it was), + $20 a year for the guide
> > info.
> The PVR-250 doesn't get you anything over the PVR-150, which is
> cheaper. A PVR-500 is a pair of 150s on a single card. I use a
> PVR-500 and an HD HomeRun, which is a pair of HDTV tuners in an
> ethernet-attached box.
> > The interface looks nice, and you get the added benefit of
> > streaming audio, web interface, etc. However, I don't plan on using
> > any of that at my TV as we use the TV speakers.
> I'm not sure why these two sentences are connected.
> > The Pros I see to building my own is.. custom configuring the box,
> > with easily expanding the amount of shows I can record (including I
> > assume having recorded DVDs on the hds to watch at any time, such as
> > my kids PowerRangers and such).
> Yes.
> > Also, if it's possible the big pro is the ability to have a
> > centralized large HD storage, maybe even a home NAS of 1TB or more,
> > and access it from any TV
> Yes.
> > ... although I am guessing the bad news is, it would require a
> > computer with capture/playback card at each TV.
> No, just playback at each TV.
> > This isn't an option for me as I only have the one box extra, and
> > leaving it running all the time with the noise it makes is not really
> > and option as well (that is to say, running 2 or 3 computers, one at
> > each TV, just for playing back videos from a central NAS is not a big
> > option for me).
> Well, there's the MVPMC. There's the X-Box Media Center, and
> older X-Boxes running Myth's frontend on Linux. And dedicated
> MythTV machines can be set to power themselves down when not in
> use.
> > An alternative > to this I *think*, is to use my laptop with pcmcia
> > card that can decode/playback movies from the NAS with wifi. Then,
> > I can just bring my laptop (with card) to any TV I want, and select
> > anything I want. If this last one IS an option, any recomendations
> > on pcmcia (or USB) card that decoded mpeg-2, mp4, etc with excellent
> > quality?
> I don't think anyone is currently shipping such a decoder card.
> However, pretty much any modern laptop, or one with an NVidia
> 5200 or later video chipset, will do a decent job decoding by
> itself.
> > The cons I see is #1, the time involved in getting the hardware
> > in there, set it up, install the OS, install the mythtv software,
> > configure everything and get it all working.
> Yes.

Installation packages like MythDora, which I started using, based on
Fedora, Mythbuntu, and KnoppMyth can get you pretty close to done
in a couple of hours, or maybe less, once you have all the HW in place.

> > The 2nd is the cost. Two tuner cards and a couple HD's will cost 3x as
> > much as the initial two-tuner 80hour tivo box. On the other hand, the
> > service, if I pay 3 year up front, is $8 a month, so within two years,
> > the home built solution would break even with the Tivo solution.
> Yes.
> > The biggest con I see is having a big computer box with fan noise
> > and hd noise next to my TV.
> 1. Doesn't have to be loud.
> 2. Doesn't have to be right next to the TV -- cables come in a
>   variety of lengths.
> > Confusion for me is things like how I split my cable output into two
> > tuners (or more...if thats possible).
> With a splitter, of course. They are cheap. My house currently
> has eight cable devices of various sorts, and I'm in no way
> unusual.

These have a Cable-TV input and  two or more Cable-TV outputs.  If your
cable signal is strong enough, that can be all it takes.  If you later find
picture quality is worse than it was before it got split, you'll need to get
distribution amplifier.  Here in the U.S., these are readily obtained from
Radio Shack, and retail stores such as Target, WalMart, etc.

> > Also, HD cable.. do I need expensive tuner cards to record HD
> > content.
> No, but you do need separate tuners for HD service. There is a
> thread about cheap ones right now.
> > The HD Tivo with 300 hour record (80 hours of HD I think) is like
> > $800. That's insane!
> Well, the 160GB TiVo is only $300, and you can add external
> storage to that now.
> > I imagine the tuner cards probably support HD already
> Only the cards that do HD by themselves.
> > Also, remote control.. I think you can get a simple IR remote, but
> > will it "take over" the cable box so that I don't need to use two
> > remotes.. I can use it like I do my current Dish one.. simply find a
> > channel, pause it, record, continue, skip, etc? Or is this not really
> > an option.. or at least as full featured for the home PC DVR unit?
> You can get as complex a remote as you want. Personally, I use a
> $20 Sony remote
>  http://www.newegg.com/Product/Product.aspx?Item=N82E16880118001
> and some people use $200 Logitech Harmony remotes, and some
> people use magic wands.
> Read the MythTV HowTo section on keys. Anything that you can do,
> you can do from a sufficiently complex remote.

Perhaps it would be good to clarify that there are two different issues
Remotely controlling the MythTV system involves attaching a device that can
receive the remote commands from the handheld remote control.  The handheld
is typically transmitting IR signals, but there exist units that transmit RF
There are a number of IR devices on the market that can be used with MythTV.
The device attached to the MythTV system *may* or *may not* also support
transmitting IR signals using IR LEDs at the end of a cable.  These IR
units can be placed where their output is visible to other devices, such as
the TV,
the cable box, etc. and with appropriate configuration, pressing keys on the
held can cause commands to be sent via the IR transmitter(s) to the other

> > I probably have some more questions.. but I think this covers most
> > things. Any info on good quality SD/HD tuner cards, and other stuff
> > (laptop tuner card, etc) would be great!
> Read the wiki.


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