MythTV Build - A Journal

A

Asgorath

[H]ard|Gawd
Joined
Jul 12, 2004
Messages
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Well, I'm building a full featured MythTV server with multiple clients and I thought I would document the process as it went along. I'll tack on any difficulties I have along with anything I see as a revelation. I have read a few threads that are along these lines in my process of researching and found them to be extremely useful. Just thought I would give back. :)

Note: All prices do not include tax or shipping. They are just give you a general idea of what to expect price wise.

My experience:
- Windows: Very
- Linux: Moderate
- Home Theatre: Very

Goals:

Architecture:
Gentoo
MythTV

- Server
-- 4 capture cards
-- Does the transcoding
-- Reliable and fault tolerant
-- High Capacity
-- Backup DVD archive

- HD Client
-- Upscaling DVD
-- MythWeather and assortment of plugins
-- 1080p output

- SD Client
-- Based around Xbox

----------------------------------------
BUILD

Sattelite System:
  • (1) SSM24 Sadoun 2x4 multiswitch : $29.05 (incl tax+ship) @ sadoun.com
  • (2) DirecTV D11 Settop boxes : $24.48 (incl tax+ship) @ ebay
  • (2) 6' RG6 Male Male Coax Patch Cables : $.....

Server:
Xbox Client:
  • (1) Samsung SDG-605 DVD Drive : $59.95 @ llama.com
  • (1) DVD Playback Kit : $12.24 (incl tax+ship) @ ebay
  • (1) Component Cable Set : $6.07 (incl tax+ship) @ ebay
  • (1) S-Video Cable Set : $6.20 (incl tax+ship) @ ebay
  • (1) Mechassault Game, original release...not the platinum version : $8.00 (incl tax+ship) @ ebay
  • (1) Xbox Controller port -> USB female adapter : $.... (incl tax+ship) @ ebay

-----------------------
Notes on Parts:
  • For the USB -> Serial Devices, I can only trust that the Aten UC232A will work. My girlfriend's dad is a programmer at NDS (programming for DirecTV), and he confirmed that most other adapters will give you lots of trouble
  • I bought both component and S-Video cables for the Xbox so that I can compare the two interfaces back to back on the television for quality
  • If you want to run short pieces of RG6 coax from your splitter into all your tuners, do not be tempted to just make your own super short cords. DTV boxes assume a semi-long cable inside and thus they tend to run somewhat high power signals. If you use a short cord you are just pushing more current than the DTV box expects and the box will heat up unnecessarily. Use at least 6' of patch between each connection to minimize problems.

Questions on Parts:
  • Is MythTV set up to take advantage of a dual core processor? I realize that a dual core will work well with multiple processes, but it seems myth doesn't really need to do multiple processes.
  • Will an AM2 based board or Intel Duo2 board be a better choice?
    A: It's up to you. They are both very capable
  • How efficent is the staggered spinup in a Highpoint RAID5 card? With lots of hard drives the combined spinup current can be very painful on the 12V rail. With a staggered spinup I won't have to use a crazy power supply.
 
Prob a real dumb question but you said HD client. Does that mean high definition? IF so, how can you get HD with just a hauppauge 150 card?
 
Trinic said:
Prob a real dumb question but you said HD client. Does that mean high definition? IF so, how can you get HD with just a hauppauge 150 card?
Click to expand...


I think he's going to grab it through serial? I.e. the hd signal gets sent out from the serial port of the directtv box, then into the USB ports...


....though, I could have sworn those serial ports are used for controlling, not capturing...



then again, he didn't actually say he will capture hd, he'll just have an hd client for gaming, upscaling purposes...


interesting project nonetheless
 
Trinic said:
Prob a real dumb question but you said HD client. Does that mean high definition? IF so, how can you get HD with just a hauppauge 150 card?
Click to expand...

High Def playback. So upconverting everything nicely into the TV's native resolution. Also upconverting DVD's inserted. I realize 480p is the best I can get from SVideo.
 
rayman2k2 said:
I think he's going to grab it through serial? I.e. the hd signal gets sent out from the serial port of the directtv box, then into the USB ports...


....though, I could have sworn those serial ports are used for controlling, not capturing...



then again, he didn't actually say he will capture hd, he'll just have an hd client for gaming, upscaling purposes...


interesting project nonetheless
Click to expand...

The serial is to change the channels. Video will be captured via SVideo. I decided to control using serial because I'll have several boxes and using a single channel serial IR based setup was very very complicated and using a bunch of USB IR blasters is complicated and expensive.

Also, the DTV boxes have a USB port, but to get serial data into it I just use the USB -> serial adapters
 
What motherboard are you looking at that has a PCI-X slot on it? I was of the understanding that those motherboards were "server" class boards, and cost some serious coin. I could be mistaken, but for my next myth server buildout, I'm planning on getting an sli or crossfire board to ensure that I have 2 pci express slots to use with raid cards. The highpoint 2320 has what appears to be mostly the same features as the 1820a you were looking at for less than a fraction of the price difference that you'll be looking at to get a pci-x motherboard. Both cards claim to have driver support for linux. I will be looking into these cards further for my own use. I know nothing of how well the staggered drive spinup works on those chipsets... none of the review sites seemed to collect data about that stuff. Too bad, really.

As for processors, I think the backend machine will benefit greatly from a dual core processor. Then you can transcode stuff while not starving the cpu feeding captures so that you don't ever get dropped frames.

As for am2 vs. core2, go with whatever fits you better... be it price, a particular motherboard that you like better... Both processors will do an admirable job for your project.

Good luck, and let me know if you have questions. Gentoo with mythtv is awesome. It just takes a little bit of investment in time. Good luck.

-q
 
PCI-X is backwards compatible with PCI. But if you run a PCI card in a PCI-X slot you will only get a 32bit connetion instead of 64bit. Myth isn't a huge bandwith hog so as long as I can feed a 10/100 connection I will be fine. Therefore I don't think I need the full 64bit PCI bus afforded by a PCI-X slot.

Therefore I can get the card for ~$150 less than the PCI-E x4 card, and also be afforded many more options on motherboards because most motherboards don't have PCI-E x4. However I could always get a motherboard that has onboard video, and then utilize the PCI-E x16 slot.

Go for the PCI-X card if you want to save cash. Also, because most motherboards only have a single PCI-E x4 or PCI-E x16 slot, you could not stack more of these cards in the future to build truly monstrous arrays. These highpoint cards are capable of stacking arrays over multiple cards. Oh can you just dream of a 16 drive RAID 6? mmmmm.

Go for PCI-E x4 card if you want better performance (but negligable difference in this myth setup)
 
Asgorath said:
PCI-X is backwards compatible with PCI.
Click to expand...
Not entirely correct. If the slot is keyed for 5V (looks like --- - ---) then that's correct. But if it's keyed for 3.3V (looks like - --- ---) then that's incorrect.
 
What problems were you having with gentoo? I know the learning curve can be steep, but once you get the hang of it, it all makes sense. Now that I'm familiar with gentoo, just about any other distribution just doesn't seem quite right. It's open source, for god's sake compile it yourself on your box. That's the holy grail of optimization.

Just my $.02. Debian is an excellent distribution too, but if gentoo is a bit much for you, debian may not be much easier. I find it easier to compile stuff by hand than end up in dependency resolution hell that only dselect will save you from.

Good Luck
-q

*edit* speaking of debian, I know that the ubuntu community is very strong and has (reputedly) the best community support. On top of that, ubuntu *is* debian, but with more recent software features (although not as tried and true as debian)
 
Gentoo is really cool, but apt-get is almost as easy as emerge, and the thing I hated about gentoo is that it took like 6 hours to get gnome2 up and running. I like to mess around with stuff, and I don't like to sit and wait for it to compile.

What type of PC are you going to be using for your HD client? I'm pretty much exhausted so forgive me if I miss it.

Also it takes the server takes very little CPU, maybe 5% recording both HD and SH at the same time, for me on a supa dupa Celeron 2.93.
 
My client PC is an athlon xp 2600 mobile. I've "done" HD content on it (for the roughly 15 minutes that I was actually able to get a signal) and the box just couldn't handle it. Dropped frames, echoing audio, the whole lot of it. I've put HD on hold until I can upgrade the cpu and vidcard. It doesn't really matter much to me right now, as I can't get a reliable signal.

You're correct that the backend system doesn't need a whole lot of cpu, except for when you're trancoding video or performing commercial flagging jobs and such.

Taking some time to compile is just one of the things you have to accept if you're going to run an optimized system. It really doesn't add much difficulty to the sytem, except that compiling X or Qt or gtk takes some time. Once I've gotten the base install just about right (kernel and USE flags, mainly) I issue:
emerge xorg qt gtk
And go to bed for the night. When I wake up, there's fresh and hot optimized binaries with that ever-so-appealing GNU aroma.

-q
 
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