[mythtv-users] Minimum pcHDTV frontend (with decent vid card)

Brad Templeton brad+myth at templetons.com
Tue Dec 7 20:49:12 UTC 2004

On Tue, Dec 07, 2004 at 08:05:16AM -0700, John Patrick Poet wrote:
> On Tue, 7 Dec 2004, Cory Papenfuss wrote:
> >  	Hey all.  I'm looking to get a pcHDTV card soon, but wanted to
> > know if I'll have to redo my frontend as well.  I've looked through the
> > archives some, but there's a pretty low SNR on actual information.
> >
> >  	Assuming an NVIDIA card (FX5200 or GF4-440), how much CPU is
> > *actually* required?  The whole point of XvMC is that the vid card does
> > the MPEG decoding, so it shouldn't take too much.
> >
> >  	What say you all?
> >
> > Thanks,
> > -Cory
> Daniel is the best one to give you an indication of how well XvMC works.  He
> has put some effort into getting XvMC to handle HD size video frames.
> Most of us using pcHDTV cards gave up on it, and splurged on a 3.0GHz HT P4
> or better, so we would not have to use XvMC.

Also, while Nvidia cards do not have this problem (they have their own
programs in the flakey drivers from nvidia which are more powerful but
can be trouble on newer kernels) a number of other cards also, to my
surprise, have limits on the size of an xvideo rendering box that are
less than the 1920 you need to feed in 1080i HDTV.

At least I found this for both the open source radeon driver and the
open source driver for the Intel Extreme Graphics chipset (which came on
my motherboard though I didn't plan on using it.)   The radeon driver
reports it can do a larger xvideo window, but really can't.   The
IEG driver reports it can only do 1600 by 1440.

We should start a database of these.

Note this is xvideo, not just xvmc.  You really must have xvideo to make
myth work.  xvmc is a great longterm goal, and if you get it running
(It has stopped working for me with the latest xorg-x11 and 2.6.9-667
kernel) it works great with mplayer and probably xine.

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