[mythtv-users] DCT-6200 w/ FireWire -- Looking for Input..

Big Wave Dave bigwavedave at gmail.com
Mon Mar 28 20:51:30 UTC 2005

> >
> > > > -I have seen that 2Ghz is recommended for an HD setup.  Is this enough
> > > > for a frontend/backend combo... when capturing via firewire?
> > >
> > > Actually, 3GHz is recommended for an HD setup. You can get away with less
> > > on a frontend-only system, but an all-in-one box needs to do more than
> > > just playback, so you'd be pushing it.
> >
> > I don't really NEED full HD quality.  I will only be using SVIDEO
> > output through an NVIDIA MX4000.
> > I am just hoping to avoid the digital-->analog-->digital conversions
> > by just using the firewire.
> >
> > Is it possible to record with firewire... but perhaps not capture at
> > full HD quality?
> No. Recording HD is a matter of dumping the encoded-by-the-head-end mpeg2
> stream to a file on disk. Can't resize it at recording time. You can
> transcode it to something smaller, but that's a rather time-consuming task,
> and won't do you any good for live TV.

Too bad... but it makes sense.  I didn't think it was possible, but
would have hated myself if it was possible and I hadn't asked.

> > If so, maybe I can get away with less than 3Ghz?  It
> > seems like the price breaks are currently just bellow that.
> With recent optimizations, while 3GHz is still recommended in your situation
> (combined backend/frontend) for optimal performance, its certainly possible
> you could get away with a bit less. I have a viewing-only system that is a
> mere 1.53GHz (Athlon XP 1800) and it handles 720p programming fine (though
> the cpu is pretty much pegged) and can *almost* keep up w/1080i and a deint
> filter (frequent stutter, but almost watchable). I've done quite a bit of
> work to tweak this machine to be able to get there though, its not something
> I'd recommend to anybody. Its more just a challenge for me -- I have a very
> under-utilized 2600 proc I could put in its place, but where's the fun in
> that? :-)

With regard to "recent optimizations", do you mean with using XV /
XVMC or with optimization of MythTV code?

> The odd thing with HD playback is that some folks with machines that should be
> more than powerful enough encounter playback problems (stutter, pegged cpu),
> while others (like myself) manage to get significantly slower systems
> working, so there's more to it than just raw CPU power. Choice of motherboard
> may have an impact, but I couldn't say definitively. Dunno about choice of
> kernel, I haven't had a problem with either stock FC3 kernels or
> hand-compiled ones.
> A 2.8GHz P4 is probably fairly safe, and you could even have success with 2.4,
> but like I said, ymmv... Hyper-Threading seems to be a big win, you
> definitely want a P4 w/HT.
Good to know.  I have heard that HT mileage varies greatly upon the
application.  It makes sense that it would work with this too..

Are there any recommendationso n FireWire PCI cards?  I've been
looking at all the usual places, just wanted to avoid any problematic
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