[mythtv-users] Solutions to tuning issues

Michael T. Dean mtdean at thirdcontact.com
Sun Feb 26 06:29:47 UTC 2006


On 02/26/2006 12:49 AM, Kichigai Mentat wrote:
>  On Feb 25, 2006, at 16.04, Michael T. Dean wrote:
>
> > On 02/24/2006 11:03 PM, Kichigai Mentat wrote:
> >
> >> I'm having trouble tuning some channels. I've been trying to
> >> fine- tune a lot of them, but with at least 70 channels, it's
> >> quite a tedious and annoying task. I'm looking into possible
> >> solutions. At the moment, I'm using analog cable connected to a
> >> PVR-150.
> >>
> > Sounds like your cable company is using HRC and you're not.  In
> > Myth you can specify the frequency table to use for tuning.  Try
> > us-ntsc-hrc (or, if not in the US/not using NTSC, choose an
> > appropriate frequency table).
> >
>  I'm not too sure about that. Most of the channels are tuning in fine,
>  but there's a handful of channels that I just can't seem to tune
>  properly.

The tuner hardware has a built-in fine-tuning mechanism which can find a 
channel even if you specify a frequency that's off by quite a margin...

> >> At the moment, the most logical option is to get a digital cable
> >> box (we have a digital cable service for the other two TVs in the
> >>  house), and just connect it to the PVR-150 through S-Video, and
> >> using either the IR-Blaster in the PVR-150, a serial IR-blaster,
> >> or a direct serial connection, to work the digital cable box.
> >>
> > That's one (rather brute force) approach...
> >
>  Well, I'm not sure I understand the "brute force" part, just
>  wondering if you could explain that a little more.

I mean that paying for a digital cable box rather than fixing the tuning 
issue is a way to get reception by working around the problem.

>  But, I'm wondering, what would be your approach to this? As I
>  understand it, besides enhancing the analog tuning, that's the other
>  option. I would be interested in looking into tuning some of the
>  digital cable channels, but it's not a deal breaker.

However, if you want the digital channels, anyway, you might as well get 
the external receiver instead of spending time fixing the analog tuning 
issue.  While I think getting an external tuner instead of fixing the 
internal tuner is a waste, getting an external tuner to receive 
additional channels is not.

> >> But I rather dislike working with LIRC. It's always rubbed me the
> >>  wrong way. and I've always considered the possibility of getting
> >>  a High-Def cable box, and using the FireWire port on it to
> >> record the data. But I'm using an XBox as a Front-End, and we
> >> only have Standard Definition televisions. The back-end is a low
> >> powered Celeron 650 MHz with 256 MB of RAM. Is there a way to
> >> have a high-def cable box scale down to something like 480p, that
> >> the XBox could be able to play this back?
> >>
> > You could auto-transcode after recording.  Then, 4-16 hours after
> > recording a 1-hour TV show (depending on hardware), you could watch
> >  it. (In other words, you don't want to do this.)
> >
>  No, I really don't want to do this. That's why I was hoping that the
>  cable box could scale it down.

Oh.  I didn't see the part about the cable box scaling it down.  Sorry.  
AIUI, the only way to get the cable box to scale it down is to use an 
NTSC output (like the S-Video or Composite outputs) on the cable box.  I 
don't think it will allow you to specify capture resolution for firewire 
output.

> >> However, I'd be willing to settle for letting MythTV just simply
> >> do automatic fine-tuning adjustments, like a cable-ready TV sets
> >> do. I've heard this system is available, but I've been as yet
> >> unable to find it. I'm running KnoppMyth R5A30.
> >>
> > I don't think there's any way to do this.  You're probably
> > confusing analog fine-tuning with digital TV channel scanning or
> > something...
>
>  Well, if you mean digital scanning of TV channels, yes. If you mean
>  tuning of digital channels, you're wrong. I'd love an auto-fine-
>  tuning system for MythTV, and I think it would be quite useful for
>  some people.

OK, let me try being more specific.  I don't think there's any way to do 
this *in Myth*.  Myth has digital TV channel scanning.  Myth does not 
have analog fine-tuning.  Since you said you've heard an automatic 
fine-tuning adjustment system was available and mentioned you'd settle 
for Myth doing the fine-tuning for you but that you were unable to find 
it in your version of KnoppMyth, I thought the "in Myth" was implied.

Mike



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