[mythtv-users] Capture card with best tuner - BT8x8, SA713x or PVR-250?

[Joe Votour]

My course of action is to get the management to try
and do something with the signal if possible.

I'm also considering a PVR-250 if that would help out.
 I shouldn't need it due to my CPU speed, but I
planned on having one hardware encoder and one
software encoder anyway at one point.  If the PVR-250
can handle the noise and let me encode without
stuttering, I'll spring for one.

Right now I'm so desperate that I'm trying to figure
out how to run OProfile - well, I've figured out how
to run it, I'm figuring out how to analyze the
results.  I'm hoping to try to figure out what's
taking the most amount of CPU time per execution,
which might help me track down something to optimize. 
I just can't tell if the numbers I'm seeing indicate
that memcpy is being called a lot, or if it's taking
up most of the CPU time, as OProfile seems to operate
a bit differently than other (GUI-based) profilers
I've used.

-- Joe

--- Richard Lee-Morlang <rick at webtownis.bc.ca> wrote:
> On Sat, 2003-08-23 at 11:42, Joe V wrote:
> 
> 
> > It's possible that the OS is doing something else,
> I
> > suppose, but I boot into run-level 3 and start
> MythTV
> > from there (using a .xinitrc).  I've removed as
> many
> > of the services as I could using ntsysv (Red Hat
> 9).
> 
> 
> Essentially the same thing I did, though I ended up
> booting into
> runlevel 5 and using gdm's autologin and so on from
> there. Still, if
> it's a system that's basically dedicated to myth,
> you shouldn't be
> running into that sort of trouble with your
> hardware.
> 
> 
> > The pictures that I took, those were of the TV. 
> It
> > was like that before I even started building the
> > MythTV box.
> 
> 
> Then it sounds like your best course of action would
> be to try to
> eliminate as much signal noise as possible in
> whatever ways you can.
> (Building management, cable company, etc..) 
> 
> 
> > As for the capture card, I've used two different
> ones
> > - a LeadTek Winfast 2000 XP Deluxe (which seemed
> to be
> > pretty bad), as well as a Pinnacle PCTV Rave,
> which
> > seems to be a bit better.  That's why I was asking
> > what kinds of cards/tuners people are using.
> 
> 
> Can't offer much help here, since the card I use
> seems to work great,
> and I haven't had any need to try any others.
> (Though I've got a PVR-250
> on my shopping list. ;-) 
> 
> I can say that I was really disappointed with the
> SAAxxxx TV-encoding
> chipset though. Don't have the exact chipset handy,
> but I could look it
> up if anyone wanted to know.
> 
> 
> > One thing that could be a cause of the problem is
> that
> > on both the Leadtek and the Pinnacle cards the
> coax
> > barrel connector isn't part of the tuner itself,
> it
> > connects to the tuner (it's a slide-on connector,
> > looks like a composite connector).  I'm thinking
> that
> > this might have something to do with it, but I
> don't
> > know how many cards actually are like this.
> 
> 
> My WinTV has the whole tuner unit, including the
> connectors, as part of
> a shielded housing built onto the card. Though I can
> see the setup you
> have possibly adding some more noise, if your
> picture isn't
> significantly noisier since you added your myth
> setup, I doubt you'd
> solve your frameloss problems with a different
> connector housing design
> or a different hookup configuration. :-(
> 
> 
> > Now then, one final question for you...  If you
> look
> > at the console, do you see any "rebuffering (X,Y)"
> > messages (where X and Y are numbers)?  Depending
> on
> > the channel I'm watching, I see these messages
> > anywhere from every 10 seconds to every 10 minutes
> > (sometimes I get a few of them every 10 seconds
> and
> > then they go away for 5-10 minutes).  In order to
> keep
> > track of the times, I modified the RingBuffer.cpp
> file
> > to print out the date/time.
> 
> 
> Yes, I've seen them, though by the looks of the
> recent console output on
> my two frontends, it only happens when I go into
> cutlist edit mode. It
> might be happening on my remote frontend during
> regular playback too,
> I'm not sure. I'll keep my eye on it.
> 
> Rick
> > _______________________________________________
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> mythtv-users at mythtv.org
>
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> 


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