[mythtv-users] Did I get this right? (Set-Up)

Andrew Balmos abalmos at gmail.com
Mon Sep 5 19:51:00 UTC 2005

On 9/4/05, Dewey Smolka <dsmolka at gmail.com> wrote:
> >
> > I never thought about the sounds from the cable box (I'm glad I asked
> > questions :), but could I not use the coax out from the top set into
> > the MythTV box and then composite from the MythTV box to the TV?
> Yes, no problem. The coax coming in carries audio and video, so
> there's no need to patch the audio into the soundcard's in. If it's
> the PVR 350 (at least as I understand it), the coax-out will also
> carry both audio and video to your TV. If you use the video card's out
> for your picture in whatever format, you'll need to get the audio out
> of your soundcard out to an amplifier -- the aux ins of any ol' stereo
> will do, and lots of TVs have the composite and stereo RCAs built in
> for plugging in camcorders. Using these is no problem -- (in fact it's
> probably the easiest and cheapest way to do it, using an S-vid to RCA
> converter and an 1/8" stereo mini to stereo RCA cable you can get at
> Radio Shack for $6 or so. I'd recommend doing it this way, because you
> seem to have more flexibility than with the 350s coax-out. Reportedly
> the 350 gives you a marginally better picture, but the hassles with X
> and the difficulties with MPEG-4 make it somewhat limited. Of course,
> with a 350, you would be able tio use either that card's out or the
> vid card's out . . .

OK, thanks for the clarification!

> > Let me get this straight, the IR Blaster is part of the capture card
> > that will change the channel on my top set?  Also, you mentioned that
> > there will be some delay when changing channel, how long of a delay
> > should I be expecting?
> >
> There are two components here, and two separtate things are going on.
> Assuming we're talking about the Hauppage remote, the IR reciever for
> the remote control plugs into the capture card. This controls the
> operation of MythTV. But MythTV needs to tell the hardware -- the
> capture card and, if necessary, the decoder box, which channel to tune
> to. With analog cable, MythTV simply tunes the proper frequency on the
> decoder card. With a cable box, it needs to send remote control
> signals to the box. This is the second module, IR blaster, an IR
> transmitter that mimics your cable companies remote.
> There is always going to be a delay when switching channels because
> you are not really watching live TV. When you select a channel, MythTV
> begins recording to a ring buffer and then immediately begins a
> playback of that recording. There are a lot of steps that have to be
> done between you pressing the channel change button and the picture
> coming out of the machine. On my P3 700 box, it takes two or three
> seconds to switch channels. On a more powerful machine it will
> certainly be quicker, but it will never be as fast as controlling the
> TV or the cable box directly.

OK, that makes sense, and I was expecting a few second delay, but from
the first comment I was thinking 20 or above second wait...

> <snip>
> > No I think I understand it all now, with the exception of the
> > questions above... Also, I read the required specs somewhere and I
> > can't seem to find them any more, I'm sure I'm over looking them...
> > But a PIII ~500Mhz, too slow for a master MythTV box?
> I'd say it's on the very trailing edge. Live TV will probably be too
> stuttery for comfort, though you should be able to record and
> playback. With a hardware card, the CPU isn't very taxed while
> recording, but playing a decent resolution video signal takes a lot of
> juice. Operations like com-flagging and transcoding will take a lot
> longer on this kind of machine as well -- I generally do transcoding
> on my P4 1.8 desktop rather than the Myth box.
> You can definitely get a system running on this that proves the
> concept, teaches you how it works, and really focuses you on what you
> need for the next one

Ya, in a little while I will be getting all the equipment and setting
up a box, mostly just to learn how it all works and such, if it's OK,
than I'll keep it.

> > Also, what is
> > the lowest end video card that I could use before I start seeing
> > degradation?
> I first ran a gf2 mmx with S-vid out. You can't find them in shops
> anymore, but I've seen them for around $10 on ebay. I've seen gf4s in
> shops for $30-$40.

I came across my old video card, a GeForce4 MX 440 with S-vid out, so
I will just throw that card into the box.

Thanks you everyone for all your help! I greatly appreciate it!

- Andrew

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