[mythtv-users] Questions: 2nd backend; PVR350 + HD3000; HD

Brad Templeton brad+myth at templetons.com
Sat Jun 24 03:19:10 UTC 2006

On Fri, Jun 23, 2006 at 10:01:41PM -0400, James Pifer wrote:
> On Fri, 2006-06-23 at 14:48 -0400, James Pifer wrote:
> Alright, here's what I think I've figured out so far. If I get a video
> card with DVI output, preferably nvidia because of the good linux
> support, I can convert DVI to component. From there I can convert
> component to what my Infocus projector wants using the included
> adapter. 

I am not sure how you can convert "DVI to component".  DVI has both
DVI digital and DVI analog in it, often, but it is usually RGB.

Component is the very different colour system based on luma and 2
chromas (Y Yb Yr), you need a special circuit to convert it such as the ~$100
box I have and don't use because I got a TV with RGB inputs.   Most
modern projectors, on the other hand, have RGB inputs because people want
to drive them from computers.   Check for that.   

Plus be sure you have dvi-analog output as the converters to component
video usually need that and can't use just DVI-D.   But this is usually
there, it's how dvi to vga converters work!

Your magic 7 pin s-video may just be y/yb/yr into a single connector.
Not a great idea, but it would work.  Not really s-video at all.

> I have a machine that I was hoping to use for this system:
> Athlon 1400+
> 768 Meg RAM
> plenty of disk

Pushing it a lot to get HDTV out of an Athlon 1400.   Perhaps with xvmc.
> Two problems with this machine:
> No PCI Express or AGP slot, so are there any NVidia cards I could use?
> Is it enough to handle HD with an HD3000?

Not without xvmc as far as I know, and frankly, probably a bit sluggish
even then.
> Other question still remains, if I get this setup working, will I be
> able to view regular recordings, MPEG2, through this TV Out? I'm
> assuming yes right now.

Once you have good output to your display, your video card can
resize as needed.   However, I have seen bugs trying to resize 1080i
down to 640x480 on nvidia, but you don't usually do that.  Instead you
run the screen at 1024x768 and let the tv-out circuits resize to 640x480,
and the xvideo buffer resize from 1080i to 1024 x 768.

In order of desireability:

    a) DVI-digital output to TV with DVI digital/HDMI input.  Pure digital
       all the way.   Beware, some DVI's fake having DVI-digital input and
       convert it to analog, in which case b is as good or better.

    b1) TV with VGA or other RGB analog input, computer with such output.
        (All computer cards have analog VGA RBG output of course.)

    b2) Video card with component video output, TV with component video in.
       (All tvs have component video in, cards with it out are more rare.)

    c) Computer with analog RGB out (vga/dvi-a), converter box to component
       video input

    y) Computer with s-video tv out, TV with s-video input
    z) Computer with composite video out, tv with composite video in.

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