[mythtv-users] Some questions before I breakout the Mastercard

[Jarod C. Wilson]

On Mar 17, 2004, at 03:44, Kevin D. Snodgrass wrote:

> Thanks for the quick reply.

No problem.

>> Quickie? That looks like it took some time... ;-) Good work though. 
>> Should be fine with that setup.
>
> At one time (25 years ago) I thought about becoming an architect.  
> Doing basic schematics like that one is not very time comsuming for 
> me. :-)

Aha. Woulda taken me the better part of a week, probably. =)

>>> 1) On a PVR-250, can I have two inputs, one coax cable and the other 
>>> S-Video or composite?  The pics look like it, but the online docs 
>>> don't answer diffinitively.
>> Yes, you can.
>
> Excellent.  I like it when my assumptions turn out to be correct.

But do note that you can only use one of the inputs at a time (some 
people miss that distinction, just wanted to throw it in for clarity's 
sake).

>>> 2) Would I be better off using a video card for playback?
>> Maybe. For standard-def TV, the PVR-350 output has the highest 
>> quality, though there are some stability issues (most of which are 
>> either now fixed or getting fixed). It doesn't work so hot for 
>> anything *but* standard-def TV though. And it'll never support output 
>> of a High-Def signal if you're thinking about going that route in the 
>> future.
>
> Well, if/when I get an HDTV I'll have to refactor.  Right now I have a 
> very nice Sanyo DS27910 (32" flat) standard def TV.  Some day I may 
> get a plasma, but that will wait till more toys get acquired. :-)

Mmm... Plasma... (I've got a RP-HDTV now, and am very happy with it, 
but again... Mmm... Plasma... ;-)

>>> 2a) If so, what video card(s) will give me the highest quality 
>>> playback?
>> A GeForce 4 MX is more or less the de facto standard. Both my 
>> production systems use one (one uses SVideo out, the other 
>> VGA->Component video adapter to my HDTV).
>
> I've always used ATI cards.  But, the newest one I have is in this 
> laptop, a Rage Mobility M3.

ATI has mediocre driver support, at least for the particular 
functionalities Myth needs.

>> I'm rather happy with my nForce2 board, w/onboard GF4MX.
>
> I think I'll try to get something like this.  No use spending money on 
> a video card if onboard video works...

Exactly. No problems whatsoever for me.

>>> I see several people using Fedora, but am dubious about using Fedora 
>>> because of the short lifespan.
>> Don't be. Fedora is excellent, and so is the community support.
>
> I didn't say Fedora wasn't good or anything.

No, I know, sorry, didn't mean to make it sound like you said it wasn't.

> It's the short lifespan that I don't like.

I was meaning more "don't worry about the life-span" , because there is 
such good community support, a large part due to the fact that the base 
distro is very good.

> Support for FC1 will dry up not long after FC2 is out.

 From Red Hat proper, yes, but not from the community.

> I'm still running RH 7.3 and 7.1 on my machines bacause I didn't need 
> anything from the newer releases, these work.

Almost all our Linux boxes at work are 7.3, with one back at 7.2, and 
then my workstation running FC1 (heavily upgraded).

>  Now that RH isn't supporting these older releases I'll have to look 
> elsewhere.  (I'm an old NetWare guy, I install it, config it, and 
> leave it alone for years. <G>)

We're still deploying new systems with 7.3. (Mostly dev workstations, 
the biggest reason for this being we need glibc 2.2.5 compatibility for 
a project we're working on).

>> RHEL3 WS? There's really no need. And nobody maintaining all the 
>> required packages for it, so you'd have to build lots of stuff 
>> yourself, which is somewhat counter-productive for an RPM-based 
>> distro, if you ask me. ;-)
>
> OK.  That idea is nuked.

Which sort of adds a point against SuSE 9, despite Maarten's objections 
to my statement that its asking for trouble. Same situation as RHEL3, 
nobody maintaining all the packages. (Though hopefully, that'll change 
in the future, because yes, SuSE 9 really is quite nice).

>>> Debian unstable
>> That's what many of the core developers use. It works, and I've used 
>> it myself, though I got annoyed with the differences from Red Hat 
>> (been on RH since 4.x also).
>
> I've been on various *nix platforms since about 1985.  They all seem 
> more alike than different.

Oh, they're definitely very similar, but its the little differences 
here and there that were annoying me. Slightly different paths for this 
and that, different init script styles, etc. I opted for minimal hassle 
with my production Myth boxes, and finally made them both Fedora.

>>> KnoppMyth (is it installable?)
>> Yes.
>
> That might be what I use.  Seems many people get it working straight 
> away.  Big bonus is having everything on one install CD.  I assume, 
> since this is Debian based, apt-get is used to update and install?

Yes, that is correct.

>>> and Gentoo are also up for consideration.
>> My second favorite distro behind Red Hat/Fedora. (#3 is SuSE, not 
>> that it matters). Lots of folks use it, and it works great, but 
>> you'll be at it for a while.
>
> I'm somewhat attracted to the idea of Gentoo.  (Re)Compiling 
> everything specifically for my system after it is installed ain't my 
> idea of fun, so compiling during install seems like a good idea.  At 
> the least I would recompile from source the kernel (I guess there is a 
> specific kernel from Axel Thimm) and all of X and KDE.

Definitely time-consuming, but rather fun, for a total geek experience.

>> Patches exist for 2.6.x. There's really no need to go 2.6 though, and
>
> The improvements in the scheduler (both process and IO) and the new 
> driver model are big things for me.  I guess using the hardware 
> [en|de]coders on the PVR-x50 cards means that won't be so important.  
> The CPU just runs the UI and does disk IO.  But doing commercial cuts 
> might be a different thing...

Could be. I'll have to try it out sometime soon, I suppose. But I have 
zero issues to speak of right now, so I haven't bothered.

>> definitely no need for SATA. But to each his own. I use a single 
>> ATA/100 drive for a 3-capture-card setup, and a 2.4-series kernel.
>
> Are you capturing at high bit rates?

Oh yeah. Higher than most people. 8Mbps min, 16Mbps peak for everything 
I intend to watch on my HDTV. 4.5/6.0 for stuff to be viewed on a 27" 
analog TV for my kid.

> Most of what I'll be recording I will want to be archive quality.

I'd call what I record archive quality. A bit space-consuming 
(3.7GB/hr), but I usually don't keep stuff around for very long. 
There's always the option to transcode to mpeg4 as well.

> If not I'd just keep using my VCRs.  (Of course the trip to Canada 
> means someone would have to change tapes all the time, which won't be 
> an issue with a PVR.)

Ditch those VCRs!!!

>> nForce2 is my personal favorite. Problems only crop up with 
>> APIC-enabled kernels, though I understand there's now a patch to 
>> remedy that. My master backend system is on an nForce2 running Fedora 
>> Core.
>
> I've looked and looked, but cannot find the answer.  What is the 
> advantage (bug free advantage) of an APIC-enabled kernel?

I believe it is supposed to improve I/O performance a bit and/or lower 
CPU usage for I/O.

> From my early days on PC-type hardware I did MS-DOS ISR hacking, so I 
> dealt with the AT-type PICs all the time.  I assume the APIC is and 
> Advanced PIC.

I think so, but I'm not altogether certain myself.

> If the kernel doesn't have APIC support that sounds like this advanced 
> feature set (more IRQs I would guess) won't be available, right?

I suppose. Its been a non-issue for me, so I haven't really looked into 
it. There were some big discussions on this list about it a few months 
back if you want to poke through the archive to absorb some info from 
people who seemed to know a fair amount about it.

>>> 6) From what I read the PVR-[23]50 cards embed the sound in the 
>>> MPEG2 stream, so if I use a 350 for playback I don't need a 
>>> soundcard, correct?
>> Not for TV, no. For everything else, yes.
>
> I don't think I'll be using very many of the other features of MythTV. 
>  Not a gamer, don't download MP3s, don't give a rip about a picture 
> gallery, don't even know what RSS feeds are, don't own a DVD and won't 
> ever rent one (virtually all movies bore me or worse).  I really need 
> a VCR (X4) replacement with the ability to burn the important 
> recordings.

So you may be gravy with just a PVR-350 for output.

>> Most standard-def TV signals don't have spiffy audio anyhow. Though 
>> you definitely want something good for HD and/or DVD/Divx.
>
> Something to consider in the future then.

HDTV is that much cooler when you can feed a raw ac3 stream to a nice 
amp... ;-)

>> You're talking about possibly wanting 4 capture cards, so you'd want 
>> to get a 6PCI/1AGP board, which would leave two free PCI slots for 
>> whatever you like, even if you have 4 capture cards and a video card. 
>> The only other route would be a micro-ATX board with 4 PCI slots, but 
>> most of them have garbage onboard video...
>
> Most of the mainboards I've been considering have 5xPCI/1xAGP and 
> onboard sound.

Yeah, the 6PCI ones are slightly more rare/expensive. Any of those have 
worth-while onboard video? I can't recall ever seeing a good ATX board 
with such a thing, only the micro-ATX ones. Though if you go split 
backend and frontend...

> The more I think about this the more I think a frontend/backend 
> solution might be best.  I'm guessing the max distance for S-Video is 
> much less than the distance from my spare bedroom to the other end of 
> my apartment.  Ethernet doesn't have those constraints...

Very true. This would mean either splitting off the 350 into the remote 
frontend machine, and recording to the local driver or over NFS back to 
the master, to be able to utilize its tuner, or foregoing the 350 and 
just using a video card in the frontend, without any capture cards in 
it. This certainly can lead to a much quieter system by the TV...

>> Probably, but nothing comes to mind right now. I'm tired, time for 
>> bed. ;-)
>
> Thanks for all the help!  And sleep is over rated. :-)  I never 
> accomplish anything useful during those 5 hours...

True. But I'm no good at work if I fall asleep on the 
keeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeys...

>>> My plan is to get at least a 3GHz processor
>> Optimal for HD.
>>> 1GB RAM
>> Overkill. 512MB should be plenty, but RAM is cheap. Both my Myth 
>> boxes have 512MB (but my workstation has 2GB now =).
>
> 512MB costs about US$80 for Kingston.  Another $80 won't break the 
> piggy bank.  And I figure Linux can cache the hell out of everything 
> to reduce the amount of work the hard drives will need to do.

Very true. I typically put 512MB in any machine as a minimum these days.

>>> 2 large SATA disks
>> SATA is overkill, though cable management and airflow is much better. 
>> But the drives are also hotter, which is detrimental to quiet 
>> operation...
>
> Thats why I was thinking about locating this machine in a different 
> room.

The more I ponder your situation, the more I think a split 
backend/frontend setup would be ideal. But then you definitely don't 
need the 3GHz CPU in the backend, or the frontend for that matter...

>>> and a DVD burner.  Might even go with SATA RAID 5, if I can get 4 
>>> disks attached.
>> Are your TV recordings really important enough to want to use RAID 
>> 5?!?
>
> I want the storage space AND the reliability.  I also expect this 
> machine to handle this task for several (5+) years. Outside of a 
> server room I've had quite a few hard drive failures.  And yes, the 
> Stanley Cup Finals are that important to me. :-)

Stereotypical die-hard Canadian hockey fan, are ya? I'm *almost* that 
way about baseball, but not quite. ;-)

>>> I'm not afraid to spend money to get what I want
>> Me neither. Just don't tell my wife. =)
>
> Ok, I won't. :-)

Me and my potential future children thank you.

-- 
Jarod C. Wilson, RHCE

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