[mythtv-users] Can a pcHDTV record standard definition?
brad at bradandkim.net
Wed Dec 13 03:38:28 UTC 2006
On Tue, 2006-12-12 at 19:59 -0700, Brian Wood wrote:
> On Dec 12, 2006, at 6:09 PM, Brad wrote:
> > On Tue, 2006-12-12 at 16:44 -0700, Brian Wood wrote:
> >> On Dec 12, 2006, at 3:54 PM, brad at bradandkim.net wrote:
> >>>> I don't yet have an HD TV but hope to in the near future. In the
> >>>> meantime, I need another capture card. If I get a pcHDTV card
> >>>> will it
> >>>> record standard definition now and allow for the HD upgrade or do
> >>>> I need
> >>>> to buy a card that will be obsolete for me in the coming year?
> >>> I think I answered my own question. pchdtv.com states that the
> >>> HD-5500
> >>> supports NTSC.
> >> Quite correct, but it supports it only as a "dumb" frame-grabber card
> >> - the Video must be compressed/encoded by your CPU.
> >> The commonly-used PVR cards have a hardware encoder on the card so
> >> their output is an MPEG stream, thus requiring no CPU power to encode
> >> the video.
> >> So as long as you don't try and use the card for NTSC on a low-
> >> powered machine it will work.
> > Ahhh...that's good to know. The backend is an AMD 64 with a Gig of
> > RAM
> > and has been fine, but I would be adding a tuner and often playback
> > to a
> > second frontend as well. I better be careful about that.
> Myth encodes video from a frame-grabber either as RtJPEG or MPEG-4.
> The former takes less CPU to encode but produces larger files.
> Playing back MPEG-4 on a F/E takes more CPU than MPEG-2 or RtJPEG.
> You can't get any help from XvMC for anything except MPEG-2, so your
> F/E CPU will have to do the decode, so I'd be careful about encoding
> MPEG-4 if you are playing back on a slow F/E.
Well, that's probably the kicker then. My main frontend is the backend
itself and I am fine there, but I have 2 other frontends that are
marginal at best. Looks like I may need to plan some upgrades in order
to make this transition.
More information about the mythtv-users